GM 3800 color under oil cap

[GerGa]

2004 Buick Lesabre 3800 SII L36 engine. Did upper and lower intake manifold gaskets with the aluminum frame lower gaskets and upgraded upper manifold at 50k miles. Did as precaution because the upper manifold was leaking oil and previous owner never changed the coolant.
Have run Pennzoil Platinum 5w30 since I bought it but it uses quite a bit of oil with that. At least a quart in 3k miles. Before a long trip recently I checked the oil and it was down a full quart, and there was some yellowish milkyness under the oil fill cap. It was a 6 hour round trip on the highway pulling a 5x8 utility trailer. The engine was run a bit hard under those circumstances because I did anywhere from 55, 60, to 65mph, a lot of that in 3rd gear rather than overdrive, and the stupid ramp on the back of the trailer acts as a sail. It makes a huge difference from 50mph folded up versus folded inside the trailer, but it's gotta be up while hauling a motorcycle.
The color under the gas cap after the trip was black so I must have burned off whatever was in there.
Full size image of oil cap

I'm thinking it is most likely coolant but would like to hear from the 3800 experts. Could my head gaskets be leaking coolant into the oil? I am on my first change to Pennzoil dino yellow bottle 5w30 since then and it uses noticeably less oil. I also wonder if letting the oil go down a quart or more is related as well.
I also noticed that the gasket that came with my intake plenum had the little injection mold nubs literally on the gasket seating surface where it seats with the lower intake manifold. It looked pretty stupid to me but I'm not an auto mechanic so what do I know. Do all the upper intake gaskets have injection mold nubs on it's seating surface?
This is the intake manifold I used. http://www.ineedparts.com/gm-intake-sure-fix-manifold-kit.html

Thanks

 

[53' Stude]

Short trip driving. Take car out for good 30minute or 1hour long good drive.

 

[Trav]

Its probably just normal condensation being burned off by the higher oil temps seen during a hard run. This is very common in the winter months.
Look down the fill hole with a good flashlight if its not milky in there your probably fine but you can do a cheap UOA to confirm.

 

[simple_gifts]

My 89 Ford I6 had a filler cap on top of a cylindrical tower; I suspect the cylindrical tower was put there so fingers could not touch the valvetrain.

In the winter months, ice would form under the cap and it would not melt, even after a substantial run.

 

[bmod305]

Normal during winter. Every 3800 I have owned looks like that in the winter especially in really cold weather or short trips.

Dave

 

[GerGa]

This was fall but maybe I was taking short trips a few days before. Most of my driving is 35 minutes to and from work monday to friday. Maybe I'll switch back to Penz Platinum and get an oil analysis if it comes back with some reason to worry.

 

[Rolla07]

Originally Posted By: Trav
Its probably just normal condensation being burned off by the higher oil temps seen during a hard run. This is very common in the winter months.
Look down the fill hole with a good flashlight if its not milky in there your probably fine but you can do a cheap UOA to confirm.


+1 Exactly

 

[beast3300]

That is normal for short trip driving. I use a piece a cardboard in front of radiator to help heat the car up faster. My work drive is only 1 mile now. Also a slightly lazy thermostat can also add to the moisture effect during the winter months. My personal favorite is Stant's Superstat. I have it in all my cars and friend's cars.

 

[jacky]

why not use hm oil? possibly overfill by a 1/2 qt

 

[Olas]

Dipstick level? Is the coolant low? Do you have a functioning heater?
If I saw that under my filler cap I'd be tempted to drain oil&coolant to see what the bulk of the fluid looks like..

 

[Bluestream]

Originally Posted By: Olas
Dipstick level? Is the coolant low? Do you have a functioning heater?
If I saw that under my filler cap I'd be tempted to drain oil&coolant to see what the bulk of the fluid looks like..


YOU would drain the oil and look at it? What you one ascertain from the look of the oil?

 

[carviewsonic]

My 3800 oil fill caps look exactly like yours in the photo, during cold weather and short tripping. Always clear up when highway running, or warm weather. As long as your not losing coolant, it should be fine.

As to oil consumption, our 2003 PA uses 1l (quart) in about 3000 miles, same as you. It doesn't bother me, I just top up occasionally.

 

[Trav]

Whenever I do LIM gaskets or plenum on these engines I do a UOA to confirm no coolant is present in the oil, its worthwhile to do it once anyway just for peace of mind that the repair is good.

 

[Lubener]

Are you losing any coolant? Mine does that during short trip/ winter driving. When I discovered moisture under my cap, it was frozen, so I knew right away it wasn't coolant. Would't hurt to check your PCV system.

 

[Bgallagher]

Originally Posted By: car51
Short trip driving. Take car out for good 30minute or 1hour long good drive.


+1 Get her on the highway for a trip. It's perfectly normal and safe.

 

[GerGa]

I've been noticing the smell of coolant around the left side of my car after driving. It's leaking out the end of the upper intake. There's only 25k miles on all new gaskets and upper plenum. I used the plenum from here http://www.ineedparts.com/gm-intake-sure-fix-manifold-kit.html it seems a bit warped at the other end because when I bolted the throttle body to the plenum, the TB was sitting too high for a bracket that braces the TB to the engine block. Otherwise I thought the plenum sat pretty flat against the lower intake.

 

[Merkava_4]

Pull that oil cap filler extension off so that you can look under the valve cover. Check to see if you have coolant/oil sludge on the rocker arms and valve springs.

 

[GerGa]

Its fine I now know the coolant loss source. The cap was normal from sort trips.

 

[Lubener]

Try re torquing the UIM bolts (88 inch lbs), but it could be warped if it was tightened unevenly.I had to tweek them shortly after replacing UIM.

 

[GerGa]

Originally Posted By: Lubener
Try re torquing the UIM bolts (88 inch lbs), but it could be warped if it was tightened unevenly.I had to tweek them shortly after replacing UIM.


I'll try that.

Does anyone know if the coolant needs to be drained before removing the plenum?