Finished Recent Top end work, few issues remain

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rockola1971

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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

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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

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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

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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

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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.
 
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Sgtduckyboy

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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
 
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Sgtduckyboy

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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

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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.
 
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Sgtduckyboy

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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!
 

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