2008 5.3 Engine Oil/Filter + Octane Rating

[CruelJung]

I drive a 2008 Yukon XL, 5.3 1500 Flex Fuel. The vehicle has 170,000+ miles on it and the AFM/DOD is both mechanically and electronically deleted. I am interested in doing my own oil changes and would like to know what oil and filter brands are most ideal for engine health and longevity.

From my current base of knowledge, I am leaning towards a Wix filter and Amsoil synthetic oil (my vehicle has already been running on synthetic, with AC Delco filters). Any suggestions or experience?

Additionally, is there any reason to run my vehicle on higher octane fuel than 87 unleaded?

 

[iamdub]

I drive a 2008 Yukon XL, 5.3 1500 Flex Fuel. The vehicle has 170,000+ miles on it and the AFM/DOD is both mechanically and electronically deleted. I am interested in doing my own oil changes and would like to know what oil and filter brands are most ideal for engine health and longevity.

From my current base of knowledge, I am leaning towards a Wix filter and Amsoil synthetic oil (my vehicle has already been running on synthetic, with AC Delco filters). Any suggestions or experience?

Additionally, is there any reason to run my vehicle on higher octane fuel than 87 unleaded?

Good job on already running synthetic. Wix is a great filter. You're all set there.

When mine was 100% stock, it would have spark knock if I gave it some moderate throttle to accelerate during hot weather if I ran 87. I know it'd knock a lot more if I were towing. 89 made a considerable improvement- it'd only knock if I floored it from a stop and only for a few ticks. 91-93 eliminated the knock. I can't say mine represents the masses. So, just listen to yours. If it knocks (sounds like clicks under load), run 89 or higher. This might only be necessary during the summer and/or if you have a little fun when you drive.


Speaking of oil, are you aware of any oil consumption? Do you check the level regularly? The PCV system in the earlier Gen 4 engines contributed to oil consumption. One of the functions of AFM exacerbated the issue. It was [mostly] resolved with a revised PCV baffle design in the driver side valve cover around 2010. If yours still has the original cover, I'd recommend you get the updated one. Also, I highly recommend a catch can.

 

[CruelJung]

Good job on already running synthetic. Wix is a great filter. You're all set there.

When mine was 100% stock, it would have spark knock if I gave it some moderate throttle to accelerate during hot weather if I ran 87. I know it'd knock a lot more if I were towing. 89 made a considerable improvement- it'd only knock if I floored it from a stop and only for a few ticks. 91-93 eliminated the knock. I can't say mine represents the masses. So, just listen to yours. If it knocks (sounds like clicks under load), run 89 or higher. This might only be necessary during the summer and/or if you have a little fun when you drive.


Speaking of oil, are you aware of any oil consumption? Do you check the level regularly? The PCV system in the earlier Gen 4 engines contributed to oil consumption. One of the functions of AFM exacerbated the issue. It was [mostly] resolved with a revised PCV baffle design in the driver side valve cover around 2010. If yours still has the original cover, I'd recommend you get the updated one. Also, I highly recommend a catch can.

Thank you for the response. I did change the oil myself, so the engine is now running with Amsoil Signature and an Amsoil EAO17 filter. I can't say if I've heard any knocking in the engine when accelerating or otherwise, but that's something I will pay closer attention to moving forward. I see on your signature that you have also deleted your truck's AFM; in reference to the knock you were experiencing prior to the delete, what octane do you run your Tahoe on now?

I will have to look into PCV system on my vehicle. I had quite a bit of work done on the engine as part of the AFM delete. I don't know about oil consumption, but I do have a minor leak around the bell housing. It was noticed when my oil was changed previously and is still active, but minor.

Before deciding to change my oil myself, after making a 6hr round trip, I noticed my oil filter was leaking and the day after returning I checked the oil before driving--it was very low. Needless to say, it seemed the right time to start doing my own oil changes. 4-5 quarts is about what I drained, but I can't say yet if that was due to the filter leaking or oil consumption. It's something I will be paying close attention to now.

 

[donjetman]

Valve cover driverside – GM# 12570427 - amazon etc

Catch can - https://www.amazon.com/PQY-Catch-Ba...9385144&sprefix=catch+can,aps,129&sr=8-8&th=1

 

[iamdub]

Thank you for the response. I did change the oil myself, so the engine is now running with Amsoil Signature and an Amsoil EAO17 filter. I can't say if I've heard any knocking in the engine when accelerating or otherwise, but that's something I will pay closer attention to moving forward. I see on your signature that you have also deleted your truck's AFM; in reference to the knock you were experiencing prior to the delete, what octane do you run your Tahoe on now?

I run 93 now just as I did before. But, I HAVE to now. That simple delete turned into a small performance upgrade- cam, stall, higher compression, tuned for 93, etc. I just think these things, in purely stock form, benefit from at least 89 and rely on the knock sensors to retard the timing, making 87 "acceptable" and that's what GM specs in the manual. I don't want any knock. Even if I had stuck to my "stock" AFM delete, I would still run 93. A few extra bucks per fill-up is still way cheaper than fractured pistons and/or rings. I'd rather the peace of mind when flooring it to pass during hot weather or when towing.

Coincidentally, I recently ran the tank very low and added about 15 gallons of 89 as a test to see "how close to the ragged edge" the tuning was. Let's just say I'm driving it easy and bought a can of octane booster until I'm due to refuel.

I will have to look into PCV system on my vehicle. I had quite a bit of work done on the engine as part of the AFM delete. I don't know about oil consumption, but I do have a minor leak around the bell housing. It was noticed when my oil was changed previously and is still active, but minor.

Before deciding to change my oil myself, after making a 6hr round trip, I noticed my oil filter was leaking and the day after returning I checked the oil before driving--it was very low. Needless to say, it seemed the right time to start doing my own oil changes. 4-5 quarts is about what I drained, but I can't say yet if that was due to the filter leaking or oil consumption. It's something I will be paying close attention to now.

Good call. Keep an eye on it and know your machine. It'd be reassuring to at least know if that driver side valve cover (as @donjetman graciously linked) was updated during your engine work. The catch can he also linked is fine. My only suggestion is to add a stainless scrubber pad for more filtering media. It goes on top of that round plate with the holes in it.

https://www.amazon.com/Scotch-Brite-214C-Stainless-Scrubbing-Scouring/dp/B002CQTXBC/ref=asc_df_B002CQTXBC/?tag=hyprod-20&linkCode=df0&hvadid=198085753806&hvpos=&hvnetw=g&hvrand=2580842754734806056&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9025338&hvtargid=pla-351298315324&psc=1

 

[CruelJung]

I run 93 now just as I did before. But, I HAVE to now. That simple delete turned into a small performance upgrade- cam, stall, higher compression, tuned for 93, etc. I just think these things, in purely stock form, benefit from at least 89 and rely on the knock sensors to retard the timing, making 87 "acceptable" and that's what GM specs in the manual. I don't want any knock. Even if I had stuck to my "stock" AFM delete, I would still run 93. A few extra bucks per fill-up is still way cheaper than fractured pistons and/or rings. I'd rather the peace of mind when flooring it to pass during hot weather or when towing.

Coincidentally, I recently ran the tank very low and added about 15 gallons of 89 as a test to see "how close to the ragged edge" the tuning was. Let's just say I'm driving it easy and bought a can of octane booster until I'm due to refuel.




Good call. Keep an eye on it and know your machine. It'd be reassuring to at least know if that driver side valve cover (as @donjetman graciously linked) was updated during your engine work. The catch can he also linked is fine. My only suggestion is to add a stainless scrubber pad for more filtering media. It goes on top of that round plate with the holes in it.

https://www.amazon.com/Scotch-Brite-214C-Stainless-Scrubbing-Scouring/dp/B002CQTXBC/ref=asc_df_B002CQTXBC/?tag=hyprod-20&linkCode=df0&hvadid=198085753806&hvpos=&hvnetw=g&hvrand=2580842754734806056&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9025338&hvtargid=pla-351298315324&psc=1

I just filled up with 93 to see if the engine ran differently and, while it could just be a placebo effect, the engine seems to run a bit more smoothly than before.

On the note of 'knock,' I have had a rumble/rattle sound since I acquired the vehicle that seemed to occur on regular, looped intervals while in drive or idle--with a corresponding vibration on the gas pedal. My mechanic thought it was coming from the catalytic converter(s), but I don't have any OBDII codes showing for that. The only codes my PCM gives me are P1153 and P1133, and I've already replaced my two upstream O2 sensors as a response--still get the codes, though. The Diablo Predator II I deleted the AFM with comes in handy to read/delete these codes, but it's something I would like to figure out over time. I only mention this because I figure my fuel injectors and these other factors you've mentioned could be related to these codes and that the vibration/sound *could* be knock.

At any rate, I plan to start using another Amsoil product, Pi, every so often alongside higher octane fuel (I'll try 91 next time and compare)--as well as a catch can and/or other upgrades--to clean up anything possible and ensure the engine is being cared for.

I greatly appreciate the detailed responses; it's been very helpful.

 

[iamdub]

I just filled up with 93 to see if the engine ran differently and, while it could just be a placebo effect, the engine seems to run a bit more smoothly than before.

On the note of 'knock,' I have had a rumble/rattle sound since I acquired the vehicle that seemed to occur on regular, looped intervals while in drive or idle--with a corresponding vibration on the gas pedal. My mechanic thought it was coming from the catalytic converter(s), but I don't have any OBDII codes showing for that. The only codes my PCM gives me are P1153 and P1133, and I've already replaced my two upstream O2 sensors as a response--still get the codes, though. The Diablo Predator II I deleted the AFM with comes in handy to read/delete these codes, but it's something I would like to figure out over time. I only mention this because I figure my fuel injectors and these other factors you've mentioned could be related to these codes and that the vibration/sound *could* be knock.

At any rate, I plan to start using another Amsoil product, Pi, every so often alongside higher octane fuel (I'll try 91 next time and compare)--as well as a catch can and/or other upgrades--to clean up anything possible and ensure the engine is being cared for.

I greatly appreciate the detailed responses; it's been very helpful.

Pinging/spark knock isn't gonna happen at idle or while sitting in gear. If it happens, it should only be when the engine's under a decent amount of load, like with hard throttle and accelerating while towing, or just really hard throttle, WOT when passing, etc. It'll only do it a few times and stop since the PCM will retard the timing. Basically, you punch it from a stop and it'll click a few times then not click any more. You won't necessarily feel the reduction in power.

 

[CruelJung]

Pinging/spark knock isn't gonna happen at idle or while sitting in gear. If it happens, it should only be when the engine's under a decent amount of load, like with hard throttle and accelerating while towing, or just really hard throttle, WOT when passing, etc. It'll only do it a few times and stop since the PCM will retard the timing. Basically, you punch it from a stop and it'll click a few times then not click any more. You won't necessarily feel the reduction in power.

Based upon that description, I don't think my engine is experiencing any spark knock with any of the octane ratings I've tried now (87, 89, 91, and 93). In fact, I recently added a fuel system cleaner (Amsoil PI) when filling my tank and that recurrent noise I described earlier seems to have ceased--which is great. If my experience with the fuel additive continues positively I'll repeat its use every oil change (3-4k miles).

My PCM is tuned for 87 (performance) at the moment. I would like to try the "Diablo Tune" (93) at some point, but not before I work on a few more things to shore up my confidence in the engine's capacity for the advanced timing.

Up next: PCV and oil leak investigation, then likely a catch can followed by an intake upgrade--I like the Airaid MIT/AEM dryflow filter combination, but would like to know more about it.

I appreciate everyone and their input in this thread, but I have to give a special thanks to you for all the details and thoughtful responses; I've checked out your build documentation, too, which is a gift to say the least. It's dubious if I will ever undergo a process like yours with my Yukon, but who knows?

 

[swathdiver]

Based upon that description, I don't think my engine is experiencing any spark knock with any of the octane ratings I've tried now (87, 89, 91, and 93). In fact, I recently added a fuel system cleaner (Amsoil PI) when filling my tank and that recurrent noise I described earlier seems to have ceased--which is great. If my experience with the fuel additive continues positively I'll repeat its use every oil change (3-4k miles).

My PCM is tuned for 87 (performance) at the moment. I would like to try the "Diablo Tune" (93) at some point, but not before I work on a few more things to shore up my confidence in the engine's capacity for the advanced timing.

Up next: PCV and oil leak investigation, then likely a catch can followed by an intake upgrade--I like the Airaid MIT/AEM dryflow filter combination, but would like to know more about it.

I appreciate everyone and their input in this thread, but I have to give a special thanks to you for all the details and thoughtful responses; I've checked out your build documentation, too, which is a gift to say the least. It's dubious if I will ever undergo a process like yours with my Yukon, but who knows?

You will be hard pressed to hear the motor knocking, we're just too insulated. You can see it on a scan tool though.

Excepting DI engines, all engines benefit from running higher octane fuel, smoother idle, better mileage, burned cleaner in the old days before "Top Tier" was adopted across all octane ratings, etc. Now, because of cost, it is rarely beneficial that way but I like my motors to have clean injectors and pistons and rings intact, my 5.3 drinks either 93 or ethanol. They love burning ethanol too!

As for oil, I switched off of Mobil 1 EP filters years ago for K&N filters with the 1" nut and run the longer PF63 as well. The M1 filters lowered my oil pressure more than my liking. The K&N is tops, nothing out flows it or filters better than it. Now that they're making PF48s and PF63s again, not "E", and now we have 3 LS engines to care for, I may go back to ACDelco filters.

A little while after I switched off M1 oil as well. My motor would rattle on start up and it does not on ACDelco's oil. The stats are better and on par with Shell Rotella's Gas Truck oil.

 

[donjetman]

I drive a 2008 Yukon XL, 5.3 1500 Flex Fuel. The vehicle has 170,000+ miles on it and the AFM/DOD is both mechanically and electronically deleted. I am interested in doing my own oil changes and would like to know what oil and filter brands are most ideal for engine health and longevity.

From my current base of knowledge, I am leaning towards a Wix filter and Amsoil synthetic oil (my vehicle has already been running on synthetic, with AC Delco filters). Any suggestions or experience?

Additionally, is there any reason to run my vehicle on higher octane fuel than 87 unleaded?

If you want higher mpg and range run higher octane fuel. I've run all grades of fuel. Knock detectors, variable valve timing, O2 sensors etc make this possible/happen.

I'm running Amsoil ASM Signature 0w-20 and Fram Ultra #10575 filter in our 180+k mile 07 Denali w/6.2L.

I occastionally run a 20-30% e85 mix with premium unleaded in this non-flexfuel vehicle with no negative results. Cost/mile is reduced and I believe the e85 may be doing some cleaning of the fuel system, combustion chamber deposits, valve deposits, and exhaust.

I don't hotrod or tow with our Denali. I get 19 mpg on the hwy and 16 mpg locally.

Here's a thread I did recently with 4 of our most recent used oil analysis reports:

https://www.tahoeyukonforum.com/threads/latest-uoa-0w-20-07-6-2l-w-180-k-mi.136491/#post-1711683

 

[iamdub]

...I like the Airaid MIT/AEM dryflow filter combination, but would like to know more about it.

Ask away!

I appreciate everyone and their input in this thread, but I have to give a special thanks to you for all the details and thoughtful responses; I've checked out your build documentation, too, which is a gift to say the least. It's dubious if I will ever undergo a process like yours with my Yukon, but who knows?

 

[George B]

My ‘13 5.3 likes 89 or E85 much better than 87.
Running a Wix or AC Delco filter on either AC Delco, Mobil1 or Supertech full syn oil.

 

[CruelJung]

Ask away!

I have quite a few questions, really, and background information to add to the questions.

All of the replies to this thread were great, but I was new to most of these concepts and especially unfamiliar with engine modifications when making the initial post. That being said, I have at least a better understanding now about what factors are at play regarding octane, catch cans, intake air flow, the PCV system, and this updated (2010-14) driver side valve cover.

This is going to be a long reply, but I figure that could be healthy for a discussion board like this and you seem to enjoy the details as well--hopefully others will chime in, too.

I'll try to break everything up into sections for easier navigation and list consolidated questions together at the end (even if it's a bit redundant) since all sections are ultimately related:


AEM Dry Filter: I watched a few video reviews about these filters, most of which focused on performance/sound--which is fine, as I am interested in that also (just not primarily)--and one other very interesting review that focused not only on performance but also filtration quality (which is more important to me, as I want the vehicle to last):

Performance Air Filters - K&N vs AEM vs BMC - DYNO Test:

I imagine the seemingly slight increase of larger particles entering the engine that a paper filter would block are likely innocuous, but I'm curious if you've had any negative experiences related to that since using the filter in your vehicle: engine idle changes, trouble codes, oil pressure, PCM re-learning?


Airaid MIT: Similar to the AEM filter, I've watched several videos and read product reviews for the Airaid MIT. Some people had issues with the throttle body end 'popping off', which seemed to be resolved by simply cleaning the mold release agent from the tube but I would be interested if you had any further insight/experience with that? Also, I read some people experienced a dashboard shake after installing this MIT and both increased oil pressure and engine temperature; did you experience any of this?

The factory intake tube has many strange caverns and channels; have you found these to be at all connected with the PCV issues (i.e., to collect oil/fuel/moisture that makes its way to the intake tube? Did you find any fluids in the stock tube when you removed it and have you found any oil making its way into the MIT?


Oil Catch Can: Initially, when learning about catch cans, I searched for further information and it seemed all was positive except some conflicting opinions about catch cans causing restriction to crankcase ventilation (not many, admittedly)--leading to blown engine/oil seals. As I mentioned earlier in this thread, I do have a small but active oil leak visible at the bell housing (likely rear main seal) to begin with, so that restriction possibility raised a concern for me. Have you had any issues with oil pressure or crankcase ventilation restriction since installing your catch can?

Also, have you found any modifications were needed for the 'clean air' vent on the passenger side, or any other areas of the engine, as part of the catch can install?


Updated Driver Side Valve Cover: (in reference to earlier in this thread) My mechanic did not update the valve cover and I have not been able to confirm any service records indicating this work was done. It looks like I will have to remove the valve cover to know if it's the updated one or not. I don't have any associated trouble codes or blue/white smoke from my exhaust and by taking a piece of paper and applying it to my open oil dipstick tube while the engine is running, my PCV has a negative vacuum (if I am understanding this correctly? the paper is lightly suctioned to the dipstick tube). All of this is to say there's no overt indication to me that my valve cover is causing a problem beyond what an oil catch can would theoretically solve.

If I do change the cover to the updated version, will it be necessary to drill out a larger weep hole (where it already exists right near the PCV valve) and/or drill more holes in the chamber leading to the PCV exit for any sloshed oil to drain from? I have seen many people talk about this, and my concern about updating the cover would be causing a problem where there currently is not one.

Example (edit: I know this guy is a bit confused about the old and updated valve cover differences, but this video explains and shows the drilling modifications the best way I've seen):

Consolidated Questions:

1. Did you experience any negative reactions from the engine or PCM from the AEM/Airaid MIT intake modification?
-shaking, (dashboard) rattling, increased engine temp. or oil pressure, oil in the MIT, etc.?

2. Should I expect a decrease in engine or engine component lifespan for filtering out less particles and potentially increasing heat/pressure in the engine with AEM/Airaid MIT?
-pre-existing oil leak cause for concern?

3. How does this intake modification affect the use of an oil catch can from your personal experience?
-increased likelihood of oil leak or crankcase restriction?
-any other modifications needed to accompany the OCC for it to function optimally (aside from the steel wool you and others suggested)?

4. Is there a good reason not to add an OCC to my engine bay now, if I do not have the updated dr. side valve cover?
-pre-existing oil leak cause for concern?

5. If I do the valve cover update, should I modify the (2010-14) dr. side valve cover or is it okay in its stock form, considering I am not experiencing any overt symptoms of oil burning in my exhaust with my current, unknown valve cover?

Thank you!

 

[iamdub]

Consolidated Questions:

1. Did you experience any negative reactions from the engine or PCM from the AEM/Airaid MIT intake modification?
-shaking, (dashboard) rattling, increased engine temp. or oil pressure, oil in the MIT, etc.?

I did not. The MIT is just a tube that deletes the resonance chambers ("mufflers") and smooths the flow of air into the throttle body. The AEM is just an air filter that seems to be every bit as good in flow and filtration as a stock or stock-style filter. The engine is still sucking air in through the same throttle body. The air is just passing through a smoother, unmuffled "straw" ahead of that throttle body. It is able to flow a little more freely, and I mean a little, resulting in a negligible increase in power at higher RPM. Nothing else is affected and there is no way it could cause negative operational effects if installed properly. The most difference it makes is sound. You simply hear the intake growl sound that is otherwise silenced by the resonator chambers on the stock intake duct.

2. Should I expect a decrease in engine or engine component lifespan for filtering out less particles and potentially increasing heat/pressure in the engine with AEM/Airaid MIT?
-pre-existing oil leak cause for concern?

First off, I'll say that I think the factory air filter is perfectly fine as an air filter. Since installing the Airaid and AEM filter about 70K miles ago, I've had my intake tube off three or four times in ~20K mile intervals. I "white glove test" the inside of the tube and have been quite pleasantly surprised every time by the absence of dust or even an appearance of smudges where I wiped it. Also, my oil is still plenty clean enough at 5,000 miles to be in service longer. I still change it and drain it into a clean container for a friend to run in his Tahoe. The MIT is just a differently-shaped tube. It, and good air filter aren't going to increase heat or pressure in the engine. They're not going to alter oil pressure or affect the operation smoothness of the engine. If there is such a change after installing the MIT, then it is caused by a faulty installation and not from the parts themselves.

The intake and filter, either stock or aftermarket, isn't going to alter a pre-existing oil leak.

3. How does this intake modification affect the use of an oil catch can from your personal experience?
-increased likelihood of oil leak or crankcase restriction?
-any other modifications needed to accompany the OCC for it to function optimally (aside from the steel wool you and others suggested)?

They are not related nor connected, so they don't affect each other. The intake duct DOES have a hose that connects to the PCV nipple on the passenger side valve cover. This is a fresh air INLET for the PCV system. A catch can goes on the nipple on the driver side valve cover that is the OUTLET for the PCV system.

As for the catch can itself, there is no need to modify it other than to increase its filtration efficiency and, if it doesn't come with one, adding that scrubber pad is a cheap and effective way to do so.

4. Is there a good reason not to add an OCC to my engine bay now, if I do not have the updated dr. side valve cover?
-pre-existing oil leak cause for concern?

Not having the updated valve cover makes an OCC more necessary. The updated valve cover keeps the oil inside the engine. The OCC catches what makes its way out of the engine and stores it in a reservoir where you'll have to drain it. The updated valve cover should be your first line of defense since it keep t the oil inside the engine so the OCC will only have to catch the smaller amount of oil that still gets past the updated valve cover.

A pre-existing oil leak isn't a cause for concern when referring to the updated valve cover or OCC. If this leak you speak of is from the driver side valve cover gasket or bolt grommets, then it can be remedied when you update the valve cover.

5. If I do the valve cover update, should I modify the (2010-14) dr. side valve cover or is it okay in its stock form, considering I am not experiencing any overt symptoms of oil burning in my exhaust with my current, unknown valve cover?

There are no modifications necessary to the valve cover.

 

[Plimbob]

Cruel, regarding your comment about a slight amount of oil around the filter, I would check the oil cooler block plate which is above your filter. The gasket is prone to seeping on these with a few miles.

 

[CruelJung]

I did not. The MIT is just a tube that deletes the resonance chambers ("mufflers") and smooths the flow of air into the throttle body. The AEM is just an air filter that seems to be every bit as good in flow and filtration as a stock or stock-style filter. The engine is still sucking air in through the same throttle body. The air is just passing through a smoother, unmuffled "straw" ahead of that throttle body. It is able to flow a little more freely, and I mean a little, resulting in a negligible increase in power at higher RPM. Nothing else is affected and there is no way it could cause negative operational effects if installed properly. The most difference it makes is sound. You simply hear the intake growl sound that is otherwise silenced by the resonator chambers on the stock intake duct.




First off, I'll say that I think the factory air filter is perfectly fine as an air filter. Since installing the Airaid and AEM filter about 70K miles ago, I've had my intake tube off three or four times in ~20K mile intervals. I "white glove test" the inside of the tube and have been quite pleasantly surprised every time by the absence of dust or even an appearance of smudges where I wiped it. Also, my oil is still plenty clean enough at 5,000 miles to be in service longer. I still change it and drain it into a clean container for a friend to run in his Tahoe. The MIT is just a differently-shaped tube. It, and good air filter aren't going to increase heat or pressure in the engine. They're not going to alter oil pressure or affect the operation smoothness of the engine. If there is such a change after installing the MIT, then it is caused by a faulty installation and not from the parts themselves.

The intake and filter, either stock or aftermarket, isn't going to alter a pre-existing oil leak.




They are not related nor connected, so they don't affect each other. The intake duct DOES have a hose that connects to the PCV nipple on the passenger side valve cover. This is a fresh air INLET for the PCV system. A catch can goes on the nipple on the driver side valve cover that is the OUTLET for the PCV system.

As for the catch can itself, there is no need to modify it other than to increase its filtration efficiency and, if it doesn't come with one, adding that scrubber pad is a cheap and effective way to do so.




Not having the updated valve cover makes an OCC more necessary. The updated valve cover keeps the oil inside the engine. The OCC catches what makes its way out of the engine and stores it in a reservoir where you'll have to drain it. The updated valve cover should be your first line of defense since it keep t the oil inside the engine so the OCC will only have to catch the smaller amount of oil that still gets past the updated valve cover.

A pre-existing oil leak isn't a cause for concern when referring to the updated valve cover or OCC. If this leak you speak of is from the driver side valve cover gasket or bolt grommets, then it can be remedied when you update the valve cover.




There are no modifications necessary to the valve cover.

Thanks so much for responding to this late reply. I appreciate the advice and personal experience. I've been holding off on these engine components while trying to absorb as much information as possible, since I'm a novice in these areas, but it hasn't been for a lack of desire to do the work.

It's good to know I don't have to potentially disfigure an OEM part (valve cover) for it to function. Bearing that in mind, I guess I'll start with the OCC and valve cover first. It's probably unnecessarily expensive, compared with cheaper options, but I like the Moroso model #85481--looks sharp and comes with a petcock valve for easy draining.

The oil leak I have is down at the bell housing (rear main seal, seemingly). From the times I've crawled underneath, it doesn't look to be sourced from any higher, but I have read that an oil pressure sensor leak can look like a rear main leak sometimes. At any rate, I think the engine is burning more oil than it's externally leaking, so the result of the valve cover swap and OCC install will be interesting. Between the oil change that started this thread and my most recent last week--4,000 miles--my engine lost a total of 1 quart of oil. I made a 500 mile trip shortly thereafter, with some 'competitive high-speed driving' involved, and I had to put in close to 1/2 quart to bring the proper oil level back after I returned. I'm thinking either my oil leak became worse or my 85-95 speeds sloshed more oil than usual into my PCV hose--probably the latter.

As I move further along with engine bay repairs and upgrades, I'll likely make more organized posts with documentation. Hopefully I haven't been breaking any kind of forum code by resuscitating the thread after so long.

Again, thank you!

 

[CruelJung]

Cruel, regarding your comment about a slight amount of oil around the filter, I would check the oil cooler block plate which is above your filter. The gasket is prone to seeping on these with a few miles.

When the leak was first discovered--before I noticed the oily filter and created this thread--I checked that plate in the hope of it being the problem and not my rear main seal; unfortunately, no leak there.

Also, the leaky oil filter was a one-off. I kept that filter and plan to open it to check for any clogging sometime soon, but I haven't done that yet. No such issue since I've been doing my own oil changes, so I think it either clogged somehow (it was loose when I removed it) or my mechanic's assistant didn't tighten it enough in the previous OCI. I've done two oil changes now with an oversized Amsoil filter and haven't had that problem since, although it's worth noting my mechanic was changing my oil in 6 or 7k mile intervals and this recent, second time I've done it myself was at 4k.

 

[iamdub]

Thanks so much for responding to this late reply. I appreciate the advice and personal experience. I've been holding off on these engine components while trying to absorb as much information as possible, since I'm a novice in these areas, but it hasn't been for a lack of desire to do the work.

That's what forums and sharing of info is for!

It's good to know I don't have to potentially disfigure an OEM part (valve cover) for it to function. Bearing that in mind, I guess I'll start with the OCC and valve cover first.

GM realized they had a flawed design in the original cover, updated it and made it a standard part going forward. You only stand to gain by updating yours.

It's probably unnecessarily expensive, compared with cheaper options, but I like the Moroso model #85481--looks sharp and comes with a petcock valve for easy draining.

I agree that the Moroso is expensive when it performs the same function as those that cost 1/10 the price. But, those cheaper options have been known to have sub-par components, such as carbon steel baffles and/or hardware on the inside that would quickly corrode. You can do some research and find "good" cheap ones. But, if your time is more valuable and you have no problem spending the money, you're guaranteed a quality part with that Moroso and it has a bracket and hoses designed specifically to fit your engine.

The oil leak I have is down at the bell housing (rear main seal, seemingly). From the times I've crawled underneath, it doesn't look to be sourced from any higher, but I have read that an oil pressure sensor leak can look like a rear main leak sometimes. At any rate, I think the engine is burning more oil than it's externally leaking, so the result of the valve cover swap and OCC install will be interesting. Between the oil change that started this thread and my most recent last week--4,000 miles--my engine lost a total of 1 quart of oil. I made a 500 mile trip shortly thereafter, with some 'competitive high-speed driving' involved, and I had to put in close to 1/2 quart to bring the proper oil level back after I returned. I'm thinking either my oil leak became worse or my 85-95 speeds sloshed more oil than usual into my PCV hose--probably the latter.

That's a considerable amount to burn and it burning more during that 500-mile trip kinda rules out that it's simply leaking out. With your engine having AFM deleted and it still burning that much oil- yes, you definitely need to make some changes. That updated cover and OCC should certainly be your first steps. I'd venture to recommend the upper engine soak just to be on the safe side.

As I move further along with engine bay repairs and upgrades, I'll likely make more organized posts with documentation. Hopefully I haven't been breaking any kind of forum code by resuscitating the thread after so long.

Again, thank you!

Absolutely! We like build/project threads. Even if yours isn't much of a build, it's still a great way to document and share your progress and results.

 

[avalonandl]

I will throw my hat in the ring on Wix filters are great. I dont care for Amsoil but thats just me. The synthecis today are so good its hard to go wrong with any major brand. Mobil, Valvloine, Pennzoil etc.

Only brand I dis is Royal Purple and STP

 

[Plimbob]

Did you check the oil level sensor on the block on the passenger side of the engine. I had to change mine out about 80K ago and based on the oil around the area it had been leaking a bit when I changed it. If it was leaking much it could make one think it may be a main.

Just a thought.