Pontiac Grand Prix 3800 oil leak??

**rschap1** · 01-13-2009, 04:41 AM

I have gotten some good stuff here before so THANKS, and here I go asking again. Wife's 2000 Grand Prix GT has a small oil leak. As I try and chase this, it is so slow and small it is hard to find. First looked like the valve cover. Only reason I even notice is that it is hitting the exhaust on the front bank of the motor stinking and smoking slightly. Last night I tried looking a bit further, since I am not convinced it is the valve cover. I pull the plastic engine cover off the top of the motor, and see small puddles in the low spots of the aluminum intake manifold. Looks like oil is getting on top of the intake, and working it's way around towards the front of the motor, dripping down the top surface of the accesory drives and water pump, then running around the plug wire looms, finally hitting the exhaust. As I look for the cause I begin wondering if there is any place oil would leak from the induction side of this motor? Doesn't look like it. The plastic intake plenum doesn't appear to be a possibility. I am now wondering if there is a PCV system or anything that could be un-hooked and blowing oil mist. Only saw a couple of 1/4" diameter hard plastic vacuum lines, and no other PCV looking stuff. I had also found tidbits of dog food on the backside manifld area. So I know it hasn't been too long since a varmit of somesort visited under the hood. Any coomon oil leaks in the vicinity I mentioned? Any other ideas? Appreciate it!! I just don't want to tear anything down to find out it is only oil I dripped over the last 120,000 miles of oil changes finally surfacing or something simple . THANKS AGAIN!!

**Bandit02** · 01-13-2009, 04:54 AM

Check the valve covers again, GM had a recall on the L67s (S/C 3800) for fires and that was oil leaking out of the valve covers and on the manifolds causing fires. Puddles on the top of the intakes are usually failing (dry rotted) seals in the fuel lines.

**rschap1** · 01-13-2009, 05:16 AM

Thanks. I'll look closer. The car is not supercharged, but is there anywhere to look for recall info? Thanks!!

**GTP231** · 01-13-2009, 08:50 AM

Its the Valve Cover Gaskets. Go to a dealer and make sure you get the orange ones as that's the new updated ones

**rschap1** · 01-13-2009, 09:04 AM

It looks like it's leaking on the "top" side though, towards the intake. Is there so much oil slinging around that it comes out there and not "puddling" lower on the exhaust side?
THANKS AGAIN!!! I will be taking a LOTS closer look at those!

**RageAgainstTheMinivan** · 01-13-2009, 09:20 AM

+1 on valve covers. I have/had a few 3800's and about half of the covers leaked. I didnt know about the recall though. Also, your pcv is on top, passenger side of the plastic plenum.

**transamprincess98** · 01-13-2009, 09:41 AM

Had the same problem with mine.Was the valve cover gaskets.

**rschap1** · 01-13-2009, 09:54 AM

Well. Sounds like I have some good reasons to replace those. AGAIN, much appreciate the help/advice!!

**310stanger** · 01-13-2009, 10:03 AM

i heard this is normally from valve cover gaskets

haha

**transamprincess98** · 01-13-2009, 10:04 AM

Once you do that expect something else to leak or break. I have more gremlins in my Grand Prix then I can count on fingers and toes. Always something stupid. I've replaced AC compressor, rear window regulator, front window switch, both rear wheel bearings & hubs, now I think the stupid car needs a steering rack

**0rion** · 01-13-2009, 10:26 AM

Originally Posted by transamprincess98

Once you do that expect something else to leak or break. I have more gremlins in my Grand Prix then I can count on fingers and toes. Always something stupid. I've replaced AC compressor, rear window regulator, front window switch, both rear wheel bearings & hubs, now I think the stupid car needs a steering rack

wow, we had a 99GTP that we took to 120k miles and the only work I ever did to it was fix the lockout on the shifter mechanism. That car was the most reliable car I've ever owned I think for that many miles.

To the OP. If you really want to make sure clean everything up and take it around the block but my money is on valve cover gaskets also...known issue.

**GTP231** · 01-13-2009, 03:47 PM

Originally Posted by 0rion

wow, we had a 99GTP that we took to 120k miles and the only work I ever did to it was fix the lockout on the shifter mechanism. That car was the most reliable car I've ever owned I think for that many miles.

To the OP. If you really want to make sure clean everything up and take it around the block but my money is on valve cover gaskets also...known issue.

Other than a bad rebuild on my trans when I exploded a LSD mine's been fine other than a pair of axles and driver's side hubs. Just hit 101K

**Zapper2003** · 01-13-2009, 05:43 PM

I'm pretty sure GM 3.8's had a weak block that would crack between the waterways and the cylinder wall, leaking coolant into the combustion chamber. I know of a few cases where that had happened around here, a couple even causing the engines to hydrolock. Anyone else heard of that?