Finished Recent Top end work, few issues remain

[iamdub]

...

Been a while, welcome back. How ya been?

 

[Sgtduckyboy]

I just went back and re-read your original post and noticed you talk about a "dimple on the larger of the two gears"- please explain. Are you talking about your timing gears? That's the only thing I can think of that matches what you're talking about, since there's nothing on the oil pump itself that you can turn around backwards. And if so, I don't see how you could have got the timing correct if you didn't have dots to line up on the upper and lower timing gears. But... if you did install the upper timing gear inside out, that's most likely your problem. My Cloyes timing set came with a camshaft thrust washer and it needed to be installed correctly or "it will cause a severe wear issue". I'm not sure of what would happen if you reinstalled the stock upper timing gear inside out but I don't think it's a good thing at all.

It was the oil pump I was referring to. If you look it up, on the gerotors, there are dimples, you dont really see them, at least I didnt at first, there is no reference to them in the instructions I found while doing this work. I found it while looking for reasons why my oil pressure is low at running temperature AFTER doing all this work. the timing chain was fine, inspected by a neighbor who has rebuilt many small blocks.

 

[Sgtduckyboy]

UPDATE: went in saturday and removed the intake manifold and injectors. Since my gasket kit had injector seals, I went ahead and removed the rail, removed injectors, cleaned them, remplaced seals, put them on the rail and let them soak in some carb cleaner. they all looked clean inside, nothing seemed to be in any of them, which is what you would think! The gasked for the manifold looked fine, nothing pinched or out of place. the stock type I bought to put back on, just didnt look as good as the Fel-pro that came with the gasket kit and we took it off, cleaned it up, inspected and put it back on. I double checked the gap on two of the spark plugs from each side, they were .004. I did find one thing odd, on the back of the intake manifold, there is a 'blow off' type of gizmo. We werent sure what position it was in, but we closed it and it was sticking open easily when opening and closing it. So we put a drop of WD-40 on it and it seemed to work better. Our guess was this was some sort of 'gate' in case a backfire occured, it could release pressure out that way and then close when normal operation occured. I am not a car genius but that is all that made sense, see the pictures yourself. Car runs great except once really warm. Put in fresh 5w40, hoping to get better oil pressure at warm idle. I still got it to set off 'oil pressure low' after sitting for 20 minutes once warmed up. If i raise the rpm about 100 rpms, its fine, OP goes up a few pounds and light goes off. I thought about raising the RPM with my diablo tuner. thats great, but it would still idle rough,even with the extra 100 rpm's. Remember, this is only at normal operating temperature. Cold is fine, warming up is fine, once warm, OP goes down to trip the light and idle starts going down, then up, and you can see it in the car lights dimming and increasing. My thoughts, tune is most likely since I do not have any DTC's. I wonder if the car is running to rich or lean. Not familiar with Fuel Injected closed loops systems to know what is the effect of being to lean/rich at idle. I was giong to try one of the two other tunes in the Diablo sport tuner. there is one that is 87 octane, better power/economy than the stock , then there is another one that is for 91 octane, I was going to save that for last. My question, is there an actual 'learn' process once the tune is reset/installed? Whether or not, is a tank of gas enough to see if it works after the tune is changed? I thought the cold weather might have something to do with it, but that is more about poor MPG's in this bitter cold. Also, remember, i have changed my MAP sensor, Cam position sensor, Engine coolant sensor and oil pressure sensor (which didnt work before i did all this and never had 'loping' at warm idle issue before.

 

[Rocket Man]

It was the oil pump I was referring to. If you look it up, on the gerotors, there are dimples, you dont really see them, at least I didnt at first, there is no reference to them in the instructions I found while doing this work. I found it while looking for reasons why my oil pressure is low at running temperature AFTER doing all this work. the timing chain was fine, inspected by a neighbor who has rebuilt many small blocks.

Here's what you said about the oil pump, which has me baffled:" i put in the melling 295HV pump. i didnt however, realize there was a 'dimple' on the larger of the two gears and not sure if that is facing in or out. I dont feel this would be an issue since it is working, but I figure, i have a 50% chance its correct. I can not find out if having it in wrong changes anything with the oil pressure or performance of the pump". Now you just said there are 'gerotors" with dimples. I don't understand. Here's a picture of the pump and as you see, there's no gears that you can put inside out, nothing with dimples. You can't remove the gear from inside the oil pump and put it in inside out, and you can't install the oil pump inside out so that's what's got me confused. The second picture is the timing gears and chain, which have dimples for timing. Those need to be lined up when you install the timing chain, and if you get either gear installed inside out you might lose oil pressure. As for that "blow off type of gizmo" on your intake manifold, that's where the vacuum hose goes for the brake master cylinder which isn't used if you have hydroboost brakes, which you must have. With hydroboost brakes, that hose is replaced with that funny-looking thing which is actually a plug for the hole in the manifold. The reason it moves in and out is because it has a quick-connect fitting that works like that. It does nothing except plug the hole, and if it was leaking you'd have a massive vacuum leak.

 

[Sgtduckyboy]

Here's what you said about the oil pump, which has me baffled:" i put in the melling 295HV pump. i didnt however, realize there was a 'dimple' on the larger of the two gears and not sure if that is facing in or out. I dont feel this would be an issue since it is working, but I figure, i have a 50% chance its correct. I can not find out if having it in wrong changes anything with the oil pressure or performance of the pump". Now you just said there are 'gerotors" with dimples. I don't understand. Here's a picture of the pump and as you see, there's no gears that you can put inside out, nothing with dimples. You can't remove the gear from inside the oil pump and put it in inside out, and you can't install the oil pump inside out so that's what's got me confused. The second picture is the timing gears and chain, which have dimples for timing. Those need to be lined up when you install the timing chain, and if you get either gear installed inside out you might lose oil pressure. As for that "blow off type of gizmo" on your intake manifold, that's where the vacuum hose goes for the brake master cylinder which isn't used if you have hydroboost brakes, which you must have. With hydroboost brakes, that hose is replaced with that funny-looking thing which is actually a plug for the hole in the manifold. The reason it moves in and out is because it has a quick-connect fitting that works like that. It does nothing except plug the hole, and if it was leaking you'd have a massive vacuum leak.

sorry, but your picture of the pump is the back side of the pump. the process i am referring to, when installing the pump is here

 

[Rocket Man]

I've never seen anyone disassemble an oil pump to install it like in that video. That's a new one on me. I love how they say disassembling the pump voids the warranty. There is a simpler way to center the pump, and I've never heard of a problem doing it the normal way. But now I see what you were talking about. Thanks. Your problem is worrisome to me though since the NBS GMT 800's normally have 40 psi at idle and 60 at higher RPM's. Mine had about 150k when I replaced the pump with a Melling standard volume and it has nearly 50 psi idle now and 65 at higher RPM's. The pressure you're reporting is closer to what the NNBS GMT 900's have but I'm not sure why.

 

[Sgtduckyboy]

I've never seen anyone disassemble an oil pump to install it like in that video. That's a new one on me. I love how they say disassembling the pump voids the warranty. There is a simpler way to center the pump, and I've never heard of a problem doing it the normal way. But now I see what you were talking about. Thanks. Your problem is worrisome to me though since the NBS GMT 800's normally have 40 psi at idle and 60 at higher RPM's. Mine had about 150k when I replaced the pump with a Melling standard volume and it has nearly 50 psi idle now and 65 at higher RPM's. The pressure you're reporting is closer to what the NNBS GMT 900's have but I'm not sure why.

Glad we got through that!
since its not that hard to do, but I'll wait until its warmer out, I'll pull the front open again and check that oil pump. And the way in the video is how you have to do it, if you dont drop the oil pan. Because you have to remove the rotors in the pump in order to rotate the pump off of the oil sump tube and likewise, to install the pump, rotating it around the oil tube. you sound like you have way more experience than I do with these, this is my first. Not sure if you had done this without removing the oil pan.

 

[Rocket Man]

I removed my oil pan but others have done it with the pan on and without disassembling the pump. It's a bit harder for sure but all the instructions I've seen do it with the pump together. That's a good idea though. Some have pinched the O-ring doing it which leads to loss of pressure too. I had a piece of the oil dipstick tube in the oil pan ( long story) which I wanted out so I dropped the pan which led to replacing the rear main seal while it was off. One thing leads to another ya know.

 

[02Lightning]

Been a while, welcome back. How ya been?

Doing good, you?

 

[iamdub]

Doing good, you?

Still "here". lol

 

[rockola1971]

Holy cow! What a soup sandwich. So you took the oil pump apart (which I doubt has caused your low oil pressure problem). If i read correctly further up your oil pressure gauge never worked before because of a bad sender? Do you even know for sure that you had normal pressure around 40psi after warmup before you started taking things apart?
You sure your timing marks are lined up correctly? It only takes one tooth off to run like crap and the computer cant make up for that.

 

[swathdiver]

Mine had about 150k when I replaced the pump with a Melling standard volume and it has nearly 50 psi idle now and 65 at higher RPM's. The pressure you're reporting is closer to what the NNBS GMT 900's have but I'm not sure why.

More volume. There are two pumps, one for AFM engines which pumps 1/3 more oil and the one that's probably the same or similar as yours for non-AFM motors.

 

[Rocket Man]

More volume. There are two pumps, one for AFM engines which pumps 1/3 more oil and the one that's probably the same or similar as yours for non-AFM motors.

I researched it before I did mine and the standard volume standard pressure was recommended for the LQ4.

 

[swathdiver]

I think that is plenty Mark. A question I ask myself is, after removing AFM, do I ran the other pump or keep the original? Mine idles right now at 30 psi hot in park. I'd be inclined to leave it as oil will still be pumped through those now defunct AFM passages.

 

[Rocket Man]

I think that is plenty Mark. A question I ask myself is, after removing AFM, do I ran the other pump or keep the original? Mine idles right now at 30 psi hot in park. I'd be inclined to leave it as oil will still be pumped through those now defunct AFM passages.

That's a very good question, I haven't researched which pump to use after you remove the AFM components. If you find any info please post it.

 

[Sgtduckyboy]

I have the 295HV pump which is more volume and pressure than the standard 295 and more than the 10295 pump. I think my problem may not be oil pump related(but not 100%). The cam I installed in the car, does cause an idle issue with stock tune. Its mild, but yet, once CL is in effect, the system is constantly trying to correct the AFR and thus dropping RPM's as it leans the mix, I believe its running rich, my MPG's are way down. Confirmed all this with a tuner over at Diablotewn. Guy has lots of references and seems to hit the mark with what I know based on my work with Harley Engines and upgrades to Cams and exhaust. Last night I dropped in the 91 tune and the 93 octane fuel. I ran it to warm this morning and not a single hesitation in rpm's at the stop light once warm. I dont believe my issue is solved, but at least its somewhat resolved. I cant do the tuning until it warms up and I'll do the 91 octane tune since I am not worried about the gas money.

To answer other questions: yes the timing marks were dead on, confirmed by neighbor who is an avid small block chevy engine rebuilder, besides, the engine runs like a naked ape for almost 400 miles now upon accelaration and at speed. And no, i dont know about the old oil pressure so all we know is what we see now. I just did my second oil change, mostly to get the damaged lifter parts out of the engine and this time I used 5w-40 and OP is holding higher once warm, which I figured, but still down around 5-10psi at times, which I hear isnt that bad at idle.

I am giong to just drive it with the 91, let it learn the map/settings, see if it gets better and once warmer, as long as nothing else occurs, then I'll pursue the tuning to dial it in better. I can tell you this, using the class 1 cam, is amazingly better with power compared to stock. My neighbor drove it and his review was this, his friend has a 6.0 2500 and thats a dog compared to my 5.3 with cam. He says its good, just get it dialed in. Its almost like a new engine again. Its not since i know its old and you just never know when something else could fail. Tranny shifts good, I do hear a 'clunk' upon take-off sometimes which may need a u-joint attention, I'll look at that once warmer unless it fails before then.

Here is the pump I put on,, HV and HP. I am not ruling out my cam bearings are responsible for the low pressure at low rpm, but its probably been that way for awhile, so no harm in trying to continue with that. http://www.jegs.com/i/Melling/689/M295HV/10002/-1

 

[Sgtduckyboy]

UPDATE: went in saturday and removed the intake manifold and injectors. Since my gasket kit had injector seals, I went ahead and removed the rail, removed injectors, cleaned them, remplaced seals, put them on the rail and let them soak in some carb cleaner. they all looked clean inside, nothing seemed to be in any of them, which is what you would think! The gasked for the manifold looked fine, nothing pinched or out of place. the stock type I bought to put back on, just didnt look as good as the Fel-pro that came with the gasket kit and we took it off, cleaned it up, inspected and put it back on. I double checked the gap on two of the spark plugs from each side, they were .004. I did find one thing odd, on the back of the intake manifold, there is a 'blow off' type of gizmo. We werent sure what position it was in, but we closed it and it was sticking open easily when opening and closing it. So we put a drop of WD-40 on it and it seemed to work better. Our guess was this was some sort of 'gate' in case a backfire occured, it could release pressure out that way and then close when normal operation occured. I am not a car genius but that is all that made sense, see the pictures yourself. Car runs great except once really warm. Put in fresh 5w40, hoping to get better oil pressure at warm idle. I still got it to set off 'oil pressure low' after sitting for 20 minutes once warmed up. If i raise the rpm about 100 rpms, its fine, OP goes up a few pounds and light goes off. I thought about raising the RPM with my diablo tuner. thats great, but it would still idle rough,even with the extra 100 rpm's. Remember, this is only at normal operating temperature. Cold is fine, warming up is fine, once warm, OP goes down to trip the light and idle starts going down, then up, and you can see it in the car lights dimming and increasing. My thoughts, tune is most likely since I do not have any DTC's. I wonder if the car is running to rich or lean. Not familiar with Fuel Injected closed loops systems to know what is the effect of being to lean/rich at idle. I was giong to try one of the two other tunes in the Diablo sport tuner. there is one that is 87 octane, better power/economy than the stock , then there is another one that is for 91 octane, I was going to save that for last. My question, is there an actual 'learn' process once the tune is reset/installed? Whether or not, is a tank of gas enough to see if it works after the tune is changed? I thought the cold weather might have something to do with it, but that is more about poor MPG's in this bitter cold. Also, remember, i have changed my MAP sensor, Cam position sensor, Engine coolant sensor and oil pressure sensor (which didnt work before i did all this and never had 'loping' at warm idle issue before.View attachment 189740 View attachment 189741

I did figure out what this is. Its where the brake booster line would go, but I have the kind that is hooked up to the power steering pump. I was wondering why it was connected that way and since this is my first LS1 engine, i havent seen where the brake booster normally connects.

 

[Rocket Man]

I did figure out what this is. Its where the brake booster line would go, but I have the kind that is hooked up to the power steering pump. I was wondering why it was connected that way and since this is my first LS1 engine, i havent seen where the brake booster normally connects.

I mentioned that awhile back. It's a vacuum line for standard brakes, or booster line like you called it. You have what's called hydroboost brakes that utilize the hydraulic pressure from the steering pump. They are better than the vacuum boost.

 

[Sgtduckyboy]

I mentioned that awhile back. It's a vacuum line for standard brakes, or booster line like you called it. You have what's called hydroboost brakes that utilize the hydraulic pressure from the steering pump. They are better than the vacuum boost.

forgive me, I'm blond. I cant remember where I found out. I also have a conversation going on a Tahoe group in Facebook.. thanks again for your input! I like the blower idea... maybe if i get crazy in a few years I'll do it!

 

[swathdiver]

That's a very good question, I haven't researched which pump to use after you remove the AFM components. If you find any info please post it.

Have you seen the pdf, "Rebuilding GM's Gen IV Engine"? Pretty cool and explains the pumps, pressures and springs and lots of other things.