Very odd oil leak and very low pressure. HELP!


97GSTspyder
12-31-2008, 03:29 AM
Ok here's the deal...Finally finished up every bit of the suspension, got it back on the ground and it looks amazing. Now here's the problem...Went for a test drive, and smelled oil. Pulled back into the garage, oil pressure gauge was reading 0 at idle, but goes up with higher RPM's. Popped the hood, and it was smoking. It's smoking from the right side of the O2 housing, and I noticed that the very left top header bolt is seeping oil!?!

These are the only things I could come up with.

1. The head is punctured where that bolt threads into (hope not).

2. The turbo is going bad, oil is getting to places it shouldn't be (explanation for the O2 housing smoking).

It looks like the O2 housing is wet with oil. But how? The oil feed line for the turbo is on the opposite side, no lines are in this area. How is there oil on the outside of the O2 housing...?

Now, it's leaking just slightly from the header bolt. Why am I running 0 psi of pressure? I could see maybe a very small drop because the leak is so small, but not from 20-25 (normal @ idle for me) to 0.

I checked the oil BEFORE taking it for the initial test drive, level was fine. I checked it after realizing I was leaking oil and it was smoking, it was at the same level. So I know it's not leaking too bad.

Any ideas guys? I'm hoping this motor isn't shitting the bed...

david-b
12-31-2008, 09:13 AM
Doesn't a couple exhaust studs on the 4g63 go right to an oil passage? I could see if the stud is loose oil will seep out from there. Could be off on that.

I would pull that last bolt and see if any more oil comes out. It may be dripping from the valve cover gasket.

If it's smoking from the O2 housing though, that seems like a bad turbo. Pull the housing off and check for in/out, side/side shaft play. Also may want to check the IC piping for oil build up.

And a leak will not affect oil pressure, at least not that much. I think the guage reads right near the oil filter which is next to the oil pump, so the pump would have to be bad in order for it to have a bad reading. Are you sure when you did the suspension that a ground or something for the oil pressure gauge wasn't knocked out? Is it stock or aftermarket?

97GSTspyder
01-01-2009, 10:25 AM
It's an aftermarket autometer cobalt gauge so it's pretty accurate. I double checked all the wires for the gauge, including the sender wire and it's all fine. I haven't really looked too far into it since last night was New Year's Eve...But after posting the original thread, I went out and looked at it more and the exhaust manifold stud that was seeping oil was loose as hell. I torqued it and it no longer leaks, so that's good. As far as the turbo, instead of pulling off the O2 housing I took the intake pipe off and there is very minimal shaft play in any direction from what I could tell.

As far as the low oil pressure, I forgot that the last time I changed the oil I used 5w-30 instead of the 10w-40 I normally use which might explain the lower oil pressure (my car has been sitting for a couple months in the garage because of the bad weather and because I was working on the suspension). But just above 0 psi still seems too low for idle when fully warmed up. On a cold motor it's around 75.

I'm probably going to do a compression test later today to see what all 4 cylinders are at...Also, could I have a bad turbo to O2 housing gasket? Maybe that would explain the smoking in that area...and since it's cold out, it would make it visible to the naked eye.

Thanks for the help, and Happy New Year's everyone!

Steve

97GSTspyder
01-01-2009, 01:04 PM
Update:

The car is still burning oil pretty bad...Bad enough to where my whole garage was full of smoke even with the one door open.

I have blown 2 turbos before and know how badly they smoke. But as of right now, my car doesn't smoke like I have a blown turbo. It smokes, but not REAL bad. And the smell of burning oil made me sick lol. So, could my turbo still possibly be bad but not bad enough to make it look like someone threw a smoke bomb under my car? Because if I remember right, the last turbo (16g) I blew, it smoked so goddamn bad that if you were driving behind me you'd probably want to kill me.

Like I said, I pulled of the intake tube and checked for shaft play. It was minimal in/out play and almost no side/side play. This is a used turbo I got from a friend last year, so I don't know how many miles were on it or if it was ever properly turbo timed.

Would it be worth the time and money for me to pull this turbo off, buy a rebuild kit, and rebuild it into a 16g? (I still have the blown 16g so I can swap parts, and this 14b has a much better turbine housing with no cracks).

Although, this still doesn't explain why my oil pressure is hardly anything at idle...

Possibly time to dig out the cherry picker :(

EDIT >> I just finished a compression test. When I pulled out the plugs, all 4 of them were completely saturated in oil! WTF? But when I did the compression test, it ran 180psi across all 4 cylinders. So it can't be a ring problem. But why are my plugs all covered in oil? Possible bad valve cover gasket? But how would the oil get past the threads of the plugs?

david-b
01-02-2009, 09:37 AM
EDIT >> I just finished a compression test. When I pulled out the plugs, all 4 of them were completely saturated in oil! WTF? But when I did the compression test, it ran 180psi across all 4 cylinders. So it can't be a ring problem. But why are my plugs all covered in oil? Possible bad valve cover gasket? But how would the oil get past the threads of the plugs?

If the plugs are in oil it could be bad rings or head gasket. It's seaping in from somewhere, burning in the combustion chamber and the rest that's not burning is going into the exhaust and O2 housing. Since your compression is good across the board, I would guess bad rings. A bad headgasket would cause low compression somewhere. You should do a leakdown test.

Add your comment to this topic!