2004 GXP Headgasket Job

[wilsonracing]

Ok, so after putting it off for a while to try to regroup my thoughts and what I've done. I finally got the motor back out and Just Now pulled the back head off again. And the gasket IS correct. So why don't I have oil to the top of the motor?? Checked the oil pump and it looks fine.

[harofreak00]

I wish I had some more helpful advice, but I don't. All I can tell you is I looked in the oil cap of my GXP while it was running and oil was splashing everywhere.

I've had several Northstars apart, did a head stud kit on one, and timing guides and tensioners on another. I did no oil pump priming and everything worked fine from the first startup.

[CMNTMXR57]

Yea, I'm sorta at a loss here too man. Could something have fallen in an oil gallery? However, there are others in the block/heads, so it wouldn't block all oil flow.

[wilsonracing]

The oil gallery isn't exposed for something to fall into. I'm thinking it's the oil pump, it almost has to be. That's the next party I'm gonna throw at it and hope it fixed the problem. Along with another head gasket.

[harofreak00]

I don't know if you were planning on buying a new one, but I have an oil pump here from a motor with 162k that skipped time.

[wilsonracing]

That's a little bit more miles them my car has on it now. Idk if it's a good idea to put a used one on it?? With the lick I've had with this thing, it would be bad two min after I put it in.. Lol

[CMNTMXR57]

I'm going a little foggy on N* blocks/heads, but the three holes at the bottom side of the block deck are the oil passages if I recall



This is why I asked if the head gasket(s) were in proper alignment.

[wilsonracing]

Yep your exactly correct, and yep the gaskets are installed correctly. If I could figure out how to attach a pic to this page I have the pic I took of it last night.

[CMNTMXR57]

Put it out on a site like imgur

then link it here using the following (without the "" marks)

"[img]"link%20to%20the%20picture%20you're%20linkinf"[/img]"

[wilsonracing]

I cant get the pic to go.
I know its right though, just gotta figure out why the pump isn't pumping.

[CMNTMXR57]

Ok, this is going to sound completely messed up (I want to use another term there, but the board auto-corrects). Anyway, early N*'s had an issue I recall with an oil pressure relief valve on the oil pump. Sometimes it gets clogged with debris. So there was a "Force priming" procedure GM called out. I'm not saying that this is the issue as it was prone to earlier N*'s, but at this point does it hurt to try??

This process is from GM to force prime the pump and relieve that pressure.

To remove particles from the relief valve in the oil pump, perform the following procedure:

1. Add an ADDITIONAL 10 to 12 quarts (liters) of engine oil to the engine. This will immerse the pump completely in oil.

2. Start the engine and repeatedly open the throttle (rev the engine) from idle to 3500 rpm. This will allow the pump to prime; cycling the relief valve forces any debris from the relief valve.

Important : Do not operate the engine above 3500 rpm. Doing so will aerate the engine oil and/or force excess engine oil into the PCV system. DO NOT DRIVE THE VEHICLE while the additional oil is in the engine.

After the engine has sufficient oil pressure, any valvetrain noise associated with this low oil pressure condition should not be evident upon restarting the vehicle and the low oil pressure and malfunction indicator lamp (service engine soon) messages should not remain illuminated.

3. After engine has sufficient oil pressure, drain the crankcase. Reinstall the engine oil pan drain plug.

4. Add 7 quarts of engine oil and check the oil level. Make sure the vehicle is on a level surface and the engine operating temperature is 1OO°C when checking the oil level with the engine stopped for 15-20 seconds.

[wilsonracing]

I seen something about that also a few weeks ago, I tried that as a last ditch effort before I pulled it out again. And it didn't work.

[CMNTMXR57]

I'm at a loss then. If there is no blockage, then it's the pump itself. But I can't think of any reason it would've broke doing what you were doing.

Stupid question... Have you changed the oil filter too?

[wilsonracing]

Yep changed the oil and filter before start up after doing the head stud and gasket rebuild. Only thing I can think is the oil pump much have gotten damaged when I head the balancer installed to deep, but I think it was only to deep by an 1/8 or so at the most. That's my only thoughts on why. I did change the oil pressure sensor also because I broke the original removing the head and exhaust manifold at the same time. But even if the pressure switch is bad ( outta the box) it still wouldn't make the oil pump not work.

[CMNTMXR57]

That might be the problem...

The bolts on the balancer require a specific torque... Something like 37ft/lb and 120* rotation after.

[wilsonracing]

I agree, That's what makes me think its the pump. I know I had the balancer a smidge deep, and over tight.

[CMNTMXR57]

Sorry, I'm trying to exhaust all potential things I can think of before you have to go that route.

[wilsonracing]

Thank you for sure, the information has helped a bunch and it's stearing me in the right direction. Just ready to get this thing done and back on the road.

[wilsonracing]

So...... After putting this piece of crap motor back together again.... With a new oil pump ($165.00) and a new head gasket ( $35.00) and all the time and energy, it runs. But NO oil again. I had pressure and oil to the top of the motor for a little bit at first start up and running. But now nothing. It ran for about 5 min with good pressure and I thought I had it figured out. But heck no. Now what????? I'm totally tired of working on this thing and done with it. Someone come buy it. $1500.00 I want this thing out of my shop.

[CMNTMXR57]

Sorry, I'm fresh outta ideas.

Where are you at? That might help.