Burning oil

[Jillb]

 

[j91z28d1]

My oil pressure is low I believe but oil level is fine...starting to think I bought a lemon

I'm sorry.

what you're seeing is actually very common on this board for this generation. yours at almost 250k miles is considered high mileage for these. honestly about 150k they are ready for some fixer ups. easy to do it you're a diy mechanic, sadly, if not, a shop can run up a bill almost as high as you paid for the truck pretty quickly.

on the upside yours is still running and driving, another guy pushed his budget to get into one for his family, got a 3rd party pre inspection and all, said it was good. valve train ate itself in a few months and shop replaced the engine. it seemed like a rough spot financially.


so the good, with your high mileage, your transmission has probably already been rebuilt. they go about 150k if you don't fix some flaws before hand that require removing the tranny to do. your low oil pressure might be a tick low, but it's pretty common. caused by a lot of different things but good part is it's still above what gm calls minimum. I'd have to look it up but it's something like 6psi at 1000 rpm hot. so as long as it's not currently tapping, and the oil pressure pops up pretty quickly when you Rev it up. it's probably not going to leave you stranded right now. it should start tapping pretty loudly before it does that. I personally depending your climate, I'd go with a thicker oil, something like a 10w40. another user here has gone as high as 20w50 without any negative side effects, and he sends used oil samples out for testing. of course up north in a cold below zero winter, 10w40 would be better. but during a hot summer whatever makes it run better, use less oil is fine.


depending on how tight your budget is, at this point. maybe just keep oil in it and enjoy driving it. others might have a better idea than me, but I can't even guess how long it will last as is. maybe forever, maybe not. there's an old saying that sometimes rings true. a chevy will run badly longer than most cars will run. haha



there's good info in these 2 sticky threads that might get you up to speed on what to expect. and maybe plan for. the trend you'll find there is these trucks will last forever if you get them early and have the budget to keep up with maintenance and fix a few engineers flaws along the way, over all being much cheaper than buying a new car. but if you walk into them without knowing what you're getting into. it can be hard to get on top of.

Thinking of Buying a 07-14 NNBS Tahoe/Suburban? Look Here

Gentleman I have been put in charge of making a sticky with common questions asked on the forum. These include common problems (please provide fixes and pics), some of the common mods (provide pics, step by step instructions, etc.) i.e. not air ride but maybe leveling the rear or front. I am...

www.tahoeyukonforum.com

IMPORTANT: The Chronicles of Low Oil Pressure by 07burb

Warning: this is a LONG read but may hold valuable information for others experiencing this same issue. This is what I've experienced and what seemed to work for me. Things may be different for you. Let me start from the beginning....there's also an amendment at the end of this post ---In June...

www.tahoeyukonforum.com

oh, and that k&n is very dirty. in general unless you need that 5 extra hp at wide open throttle. we tend to run stock air boxes with good paper filters. they keep a lot of dirt out of the engine that a k&n doesn't. plus the mass air flow sensor is picky about how the air flows thru it and gm put a lot of effort into getting smooth airflow across that sensor. it's honestly not a huge deal, but in states with picky emissions testing, some have had to go back to stock airboxs to get emissions based fault codes to clear. if yours is a daily driver, you might ask someone with a stock one if they want to buy your k&n setup plus give you their stock one. might make a few $ and come out with a better running setup in the long run.


good luck with it. it looks nice in the pics.

 

[Jillb]

I'm sorry.

what you're seeing is actually very common on this board for this generation. yours at almost 250k miles is considered high mileage for these. honestly about 150k they are ready for some fixer ups. easy to do it you're a diy mechanic, sadly, if not, a shop can run up a bill almost as high as you paid for the truck pretty quickly.

on the upside yours is still running and driving, another guy pushed his budget to get into one for his family, got a 3rd party pre inspection and all, said it was good. valve train ate itself in a few months and shop replaced the engine. it seemed like a rough spot financially.


so the good, with your high mileage, your transmission has probably already been rebuilt. they go about 150k if you don't fix some flaws before hand that require removing the tranny to do. your low oil pressure might be a tick low, but it's pretty common. caused by a lot of different things but good part is it's still above what gm calls minimum. I'd have to look it up but it's something like 6psi at 1000 rpm hot. so as long as it's not currently tapping, and the oil pressure pops up pretty quickly when you Rev it up. it's probably not going to leave you stranded right now. it should start tapping pretty loudly before it does that. I personally depending your climate, I'd go with a thicker oil, something like a 10w40. another user here has gone as high as 20w50 without any negative side effects, and he sends used oil samples out for testing. of course up north in a cold below zero winter, 10w40 would be better. but during a hot summer whatever makes it run better, use less oil is fine.


depending on how tight your budget is, at this point. maybe just keep oil in it and enjoy driving it. others might have a better idea than me, but I can't even guess how long it will last as is. maybe forever, maybe not. there's an old saying that sometimes rings true. a chevy will run badly longer than most cars will run. haha



there's good info in these 2 sticky threads that might get you up to speed on what to expect. and maybe plan for. the trend you'll find there is these trucks will last forever if you get them early and have the budget to keep up with maintenance and fix a few engineers flaws along the way, over all being much cheaper than buying a new car. but if you walk into them without knowing what you're getting into. it can be hard to get on top of.

Thinking of Buying a 07-14 NNBS Tahoe/Suburban? Look Here

Gentleman I have been put in charge of making a sticky with common questions asked on the forum. These include common problems (please provide fixes and pics), some of the common mods (provide pics, step by step instructions, etc.) i.e. not air ride but maybe leveling the rear or front. I am...

www.tahoeyukonforum.com

IMPORTANT: The Chronicles of Low Oil Pressure by 07burb

Warning: this is a LONG read but may hold valuable information for others experiencing this same issue. This is what I've experienced and what seemed to work for me. Things may be different for you. Let me start from the beginning....there's also an amendment at the end of this post ---In June...

www.tahoeyukonforum.com

oh, and that k&n is very dirty. in general unless you need that 5 extra hp at wide open throttle. we tend to run stock air boxes with good paper filters. they keep a lot of dirt out of the engine that a k&n doesn't. plus the mass air flow sensor is picky about how the air flows thru it and gm put a lot of effort into getting smooth airflow across that sensor. it's honestly not a huge deal, but in states with picky emissions testing, some have had to go back to stock airboxs to get emissions based fault codes to clear. if yours is a daily driver, you might ask someone with a stock one if they want to buy your k&n setup plus give you their stock one. might make a few $ and come out with a better running setup in the long run.


good luck with it. it looks nice in the pics.

Very very helpful info! Thank you so much! I live in Southern Missouri, so about to head into a hot summer...thinking of going with a 10w40 and as you suggested go back to stock air filter and diagnosing the misfire...a tune up and oil change and air filter is about all I can do right now but in February of next year might as well drop a new motor in it when I will have the cash to do so! Thank you to all that has replied! What a great forum!

 

[NardDog]

Wow, looks great!

I tried to post attachments/photos but not sure where or what happened to them

Its seems like your oil pressure is good. The catalytic converter can be purchased thru Rock auto and the have a shop weld it up. Then have a shop or a friend look to see if there are any codes stored in the memory of the truck, maybe a O2 sensor bank code. Lastly, keep an eye on the oil consumption. If it gets ridiculous you may have to consider a repair otherwise get used to the idea of checking the oil more often and topping off when needed. Its another chore I know but it ls better than buying a new truck. I would say you have a truck that with proper maintenance will last you a long time!

 

[Jillb]

Wow, looks great!

Its seems like your oil pressure is good. Have a shop or a friend look to see if there are any codes stored in the memory of the truck, maybe a O2 sensor bank code. If there are no stored codes I would say you have a truck that with proper maintenance will last you a long time!

Will do thank you and thanks for the replies!

 

[strutaeng]

It's "only" misfiring on cylinder 5?! No body has mentioned op is obviously running it with a misfire?

Running it with a misfire will destroy the catalytic converters... that's problem #1. Fix the misfire ASAP.

Problem #2 is oil pressure? Maybe, IDK on that one. If you don't have the AFM, that's fine.

Problem #3 is it's burning oil? This can actually cause problem #1, but you need further diagnosis to determine this...

I wouldn't say you bought a lemon. Afterall, it's a 200k+ vehicle. Maybe you bought someone's problems? I can see that happening. But at 200k+, that's to be expected, no?

 

[houstontaylor]

I have a 2003 Chevy Tahoe and at 290,000 miles it suddenly started burning a lot of oil, like in your case. Until then it was not burning any significant amount of oil. I figured that something internal broke and rather than digging into the engine to have it fixed I had the engine replaced with a remanufactured one. I never did find out what caused that though.

 

[jwth]

pull the number 5 plug and take s look at it. if it has been burninh oil it might be just worn valve stem guide seal which would foul the plug. If the plug is clean it may have an injector not firing or clogged up, may run thru oil pushing a dead cylinder.
switching to a heavier weight oil might pick up th oil pressure but getting a mechanical guage reading would be the the way to go to get a true picture. Sometimes an oil pump pick up tube seal will give low pressure

 

[hagar]

Replace your drivers side valve cover with the dorman 264-969 as a start for the oil burning issue. Change your plugs and cylinder 5 will most likely be getting oil build up on it from the oil burning problem causing the misfire, then run penzoil 5w30 synthetic high mileage formula with a half bottle of Lucas synthetic oil stabilizer. That is the best formula I could come up with after trial and error for the typical oil burning problem on some of these engines. I did it this way to try and make the oil stickier so it doesn't spash around as much, and it has been taking engines that were burning a liter of oil per 800 kms (i am Canadian eh,) down to a liter of oil every 2000 to 2500 kms, wich is livable.

Then pull your oil pressure sensor and oil pressure screen, throw the screen in the garbage, put in a new sensor with no screen, and change your oil every 4 thousand miles.

Then turn off the dod system with a tune.

 

[jwth]

rotten egg smell is sometime caused by tje moxture being too lean. The cold air intake will chamge yhr moxture due to less restrictions and the engine tine might nerd to be modified for that

 

[NardDog]

Replace your drivers side valve cover with the dorman 264-969 as a start for the oil burning issue. Change your plugs and cylinder 5 will most likely be getting oil build up on it from the oil burning problem causing the misfire, then run penzoil 5w30 synthetic high mileage formula with a half bottle of Lucas synthetic oil stabilizer. That is the best formula I could come up with after trial and error for the typical oil burning problem on some of these engines. I did it this way to try and make the oil stickier so it doesn't spash around as much, and it has been taking engines that were burning a liter of oil per 800 kms (i am Canadian eh,) down to a liter of oil every 2000 to 2500 kms, wich is livable.

Then pull your oil pressure sensor and oil pressure screen, throw the screen in the garbage, put in a new sensor with no screen, and change your oil every 4 thousand miles.

Then turn off the dod system with a tune.

My truck was burning some serious amounts of oil for a long time. It didn’t ruin the Cats until last year. Since then I ran Amsoils engine flush and my oil consumption has been cut in half. Either the piston rings were stuck or valves were letting oil thru not sure which but the flush really helped me.

 

[Lil Timmy Shy]

My truck was burning some serious amounts of oil for a long time. It didn’t ruin the Cats until last year. Since then I ran Amsoils engine flush and my oil consumption has been cut in half. Either the piston rings were stuck or valves were letting oil thru not sure which but the flush really helped me.

I seriously wonder.......... what would happen if you did another Amsoil flush - and then another - and then another - and then another, ad nauseum. Maybe your engine would get to the point it wasn't using any oil? I am very fortunate so far; no oil consumption, and no slipping tranny. But, I am only at 37K on my 2014. However, I am meticulous about changing oil on schedule with synthetic blend, and having the tranny serviced faithfully. And I have an AFM delete. Plus, I baby the transmission as far as shifting it hard via rapid launches, etc.
If I had it to do all over again, I'd have kept my 2003 with 230K on the clock. What a fool I was.........

 

[Charlie207]

I seriously wonder.......... what would happen if you did another Amsoil flush - and then another - and then another - and then another, ad nauseum. Maybe your engine would get to the point it wasn't using any oil? I am very fortunate so far; no oil consumption, and no slipping tranny. But, I am only at 37K on my 2014. However, I am meticulous about changing oil on schedule with synthetic blend, and having the tranny serviced faithfully. And I have an AFM delete. Plus, I baby the transmission as far as shifting it hard via rapid launches, etc.
If I had it to do all over again, I'd have kept my 2003 with 230K on the clock. What a fool I was.........

The GMT900s are fine. If you upgrade the torque converter and ensure proper fluid cooling (well known/well documented issues), you should be fine to drive it normally.

 

[RET423]

The rotten egg smell means at least one bank is running rich, if it's not throwing a code for that it means the 02 sensor is not reporting the rich condition so it's likely reporting a false lean condition & the PCM is trying to compensate by dumping more fuel

A quick test is unplug both primary 02 sensors & start the car, it will throw a code but if the rotten egg smell is gone then you know you need to replace the primary 02 sensors

Good luck!

 

[Lil Timmy Shy]

The GMT900s are fine. If you upgrade the torque converter and ensure proper fluid cooling (well known/well documented issues), you should be fine to drive it normally.

Yeah, I've been hearing about how "fine" they are at every transmission shop I've ever queried about the 6L80e reliability. I am hoping that since my unit has never had the "transmission cooker" thermostat in the cooling block line, that I will dodge that bullet. But, it still has a notoriously weak torque converter. Then, all I will have to fret with is the notorious AFM valve train issues/oil consumption, etc.........

 

[Airman68]

I agree with the stock air filter, plenty good for everyday driving. One thing I didn't see is the AFM issues. If it were me, I would disable the AFM to try to prevent any issues down the line. Very easy to do. Amazon sells modules you can plug into the OBD port. I have a 2008 with 210k miles. runs great, doesn't burn much oil, just need to keep an eye on it. Overall your truck looks very nice and clean.

 

[EddieC]

I learned my lesson on fancy intake/filter setups on a C5 Corvette. The one I bought claimed 30+ hp increase; My seat of the pants dyno didn't feel it. The only noticeable change was a bit more intake noise. Well there was one other advantage because it impressed the banker who bought it from me but then again he didn't know how to drive stick (which it was).

I think GM and most manufacturers put much time into and know what is best for their engines.

 

[EddieC]

My truck was burning some serious amounts of oil for a long time. It didn’t ruin the Cats until last year. Since then I ran Amsoils engine flush and my oil consumption has been cut in half. Either the piston rings were stuck or valves were letting oil thru not sure which but the flush really helped me.

I recently saw Valvoline Restore and Protect motor oil. Any thoughts on that?

 

[Charlie207]

I recently saw Valvoline Restore and Protect motor oil. Any thoughts on that?

A bunch of folks are running it on this site. I think there is a dedicated thread.

I had it in my last engine, and it definitely was removing deposits, based on the dark color coming out of the oil pan. I just threw some in my 2nd engine, but doubt it'll do as much cleaning on a fresh build.

 

[NardDog]

I recently saw Valvoline Restore and Protect motor oil. Any thoughts on that?

Never tried this one.