Oil Pressure/Smoke ?'s

[turbonut85]

So I took the GN to a local show yesterday....Here is what I noticed: Upon start-up...with engine cold I had about 50-55 psi on the oil pressure gauge. The more I drove it, and the hotter it got, the pressure would drop with the RPMs...all the way down to 10 lbs in drive, stopped at a light. What would cause this?? Also, car puffs blue smoke upon start-up and has a burning oil smell in the exhaust...but I can only see it intermittenly. Could this be a bad seal in the turbo?? Are these two problems likely to be related?? If the seal was bad in the turbo, could it be leaking exhaust into the center section of the turbo thus heating the oil and thinning it out?? Would that cause the drop in oil pressure?? Help me out here ---Keith

 

[conn84gn]

How many miles?
What oil visc. 10-30?
Plugs black?

 

[turbonut85]

How many miles?
What oil visc. 10-30?
Plugs black?

About 500-600 miles on a fresh rebuild. Oil visc is 10w30...just changed it. Plugs are normal to slightly white. Problems were there before the oil change too.

 

[conn84gn]

How hot a day was it

 

[turbonut85]

Not hot at all...Iowa sucks for weather. Wasn't even 70 degrees. Car temp was never over 168 degrees.

 

[Jerryl]

Two issues;
Oil pressure and oil use.

For oil pressure;
Did this low oil pressure start suddenly?
Pull the cover of the pump and verify the end clearance.
Also try a thicker oil for now.

As far as oil use;
Could be the turbo seal, maybe rings not fully seated, valve guides.
Does it only smoke when you get in the throttle?
TB or DP wet with oil?

 

[turbonut85]

Two issues;
Oil pressure and oil use.

For oil pressure;
Did this low oil pressure start suddenly?
Pull the cover of the pump and verify the end clearance.
Also try a thicker oil for now.

As far as oil use;
Could be the turbo seal, maybe rings not fully seated, valve guides.
Does it only smoke when you get in the throttle?
TB or DP wet with oil?

Don't believe this sterted suddenly. Pretty sure the rings are fully seated...not getting any oil on the plugs. Doesn't really smoke when I get into it, mostly at idle. Like I said, when I drive it around and come to a stop, I can smell it in the exhaust, and sometimes I can see it too. I was getting some oily residue on the back side of the TB blade...guess I thought it was being sucked in there via the PCV so I changed that. Haven't checked it since. I'll check that. Didn't really wanna pull the DP til I get the one I just bought but it's looking like that is the next place to look. I'm thinking it MIGHT be consuming some oil but I dunno...too early to tell since I just changed it Thursday night, and only drove it on Saturday.:redface: Guess I'm gonna have to drive it more......:biggrin:

 

[Jerryl]

Don't believe this sterted suddenly. Pretty sure the rings are fully seated...not getting any oil on the plugs. Doesn't really smoke when I get into it, mostly at idle. Like I said, when I drive it around and come to a stop, I can smell it in the exhaust, and sometimes I can see it too. I was getting some oily residue on the back side of the TB blade...guess I thought it was being sucked in there via the PCV so I changed that. Haven't checked it since. I'll check that. Didn't really wanna pull the DP til I get the one I just bought but it's looking like that is the next place to look. I'm thinking it MIGHT be consuming some oil but I dunno...too early to tell since I just changed it Thursday night, and only drove it on Saturday.:redface: Guess I'm gonna have to drive it more......:biggrin:

If the oil pressure did not start suddenly on a fresh build, re-check the oil pump end clearance.

 

[turbonut85]

If the oil pressure did not start suddenly on a fresh build, re-check the oil pump end clearance.

Just to clarify, When I start the car....(cold engine) the oil pressure is normal. i.e.: jumps right up to 50-55 psi. As I drive the car (engine up to normal temp) the oil pressure seems to fade off. 25-35 psi at about 1800-2200 rpm, and all the way down to 10 psi at idle (800 rpm) I did look into the TB and there seems to be an oily film on the inside of the TB blade. Turbo seal??

 

[turbonut85]

So I took 5 minutes and installed the restricted Y into the boost line...and when I took the old Y out, oil dripped out of it. Kinda thinkin my turbo is blowing oil ...what do you guys think??

 

[BEATAV8]

cut open your oil filter and see what's inside. It will tell you a lot about the health of the engine.

if the turbo is blowing oil past the comp seal it will have excessive oil in the compressor discharge. Could be a drainage issue for the turbo or a high crankcase pressure problem. But if the car only smokes on startup that's typically a valve stem seal leak issue.

You could try eliminating the PCV system and running with open breathers on both valve covers. This is the way I like to run but you will smell the blowby at a stop light (valvoline has a nice bouqet). Without a PCV you should not see oil in the doghouse or around the throttle body. And if oil from the PCV is causinig your smoke problem then it should go away too.

 

[turbonut85]

I just pulled the inlet pipe and the DP and they are very black like the car is running very rich...but the O2 sensor is light tan like it is running lean??? DP is dry for the most part...If the seal was blowing oil on the compressor side, wouldn't there be oil on the plugs?? Maybe it is still sucking through the PCV?? Pretty sure the car is running lean now...Gettin some knock and it even dieseled on me once! BLM's are normal (125-129) but they fluctuate while I drive...all the way up to 140-142. I know the inlet pipe was cracked so that could be causing the lean condition....right?? What do you guys think??

 

[turbonut85]

So I just pulled the turbo and this is what I found...

 

[turbonut85]

...And this is what I'm gonna do to fix it....:biggrin: :biggrin: ...ain't life a b!@%h??

 

[Boost231]

looks like your pulling oil threw the pcv and into the intake pipe. plug the pcv off.

 

[BRAD_PADGETT]

If you are running the stock oil fill tube setup the oil fill cap could be defective causing pressurized block. I ran into this problem. Try running the car without the oil fill cap. Brad