Yellow Oil Goo Under Oil Cap Suggestion

[Skoobahead]

I've had the common condensation under the oil cap and surrounding area on my 2.0 Beetle since I've owned it.(2 years) Today I decided to check the hose connected to the valve cover that goes to the PCV valve in the intake plenum hose. TOTALLY FILLED WITH GOO! I recommend removing this hose assembly and cleaning it out. None of the Crankcase ventilation could have gotten into the intake plenum as designed.

[Toad]

here's a question, do you do primarialy short trips, or mostly long trips?

the yellow goo is usally caused by condensation on the valve cover/oil cap that never fully evaporates because the oil never gets to full temperature long enough to get rid of the water. also replace the rubber seal under the oil cap. that also causes it if its dried out.

[oceanjoe89]

HA! it is so weird that you brought this up because today I checked my oil and I had remembered hearing about people going on about foam on the oil cap, so i pulled it off and sure enough there was a little bit of it on the cap! it looked mostly like water and I can attribute that to the fact that my bug hasn't seen a highway journey until just this past week when i started commuting to school daily again...

[flip240]

our beetle is primarily driven highway for at least 20-30 mins each use, and we still got that yellow goo on the oil cap. it stopped coming back after I cleaned out the pcv system (that was clogged).

same thing happened on my friend's e36 328i that had a clogged pressure regulator

[oceanjoe89]

hmm maybe i will poke around in the pcv system and just make sure there aren't any blockages

[cep]

This is the only engine I've ever seen do this. Our '02 is driven mostly on the highway and the cap looks terrible on it. Not only yellow goo, if you wipe it off with a cloth, rusty crap comes with it.

I was *hoping* that a change of thermostat would fix it. The thinking was that the engine was never getting up to full operating temp and therefore never burning off the condensation.

So much for that theory.

[D2Beetle]

Originally Posted by flip240

our beetle is primarily driven highway for at least 20-30 mins each use, and we still got that yellow goo on the oil cap. it stopped coming back after I cleaned out the pcv system (that was clogged).

same thing happened on my friend's e36 328i that had a clogged pressure regulator

My '98 and '99 still do it occasionally and I drive 28 miles one way, everyday; however my speed is usually 55 or less.

[Beckweed]

I'm glad this was brought up b/c I have this problem too. I've changed the rubber seal on the oil fill cap and it hasn't helped...still getting the yellow goo.

I didn't think the gls 2.0 had a pcv valve and didn't consider going this route. Mine is a 1999. Maybe it's just my year/engine (AEG) that doesn't have a pcv system(although I'm not sure what other kind of ventilation system it would have). Am I wrong?

Thanks,
Becky

[Skoobahead]

My driving is mixed. I don't believe driving style matters on this engine.
Actually on the 2.0 the system consists of a breather hose between the valve cover and the intake air boot. On the air boot you will see an electical connector. This is for the heating element to prevent icing during cold weather. It appears that this is also the PCV valve assy.My heating element/valve was covered in Grey Poupon!

[cep]

Originally Posted by cep

This is the only engine I've ever seen do this. Our '02 is driven mostly on the highway and the cap looks terrible on it. Not only yellow goo, if you wipe it off with a cloth, rusty crap comes with it.

I was *hoping* that a change of thermostat would fix it. The thinking was that the engine was never getting up to full operating temp and therefore never burning off the condensation.

So much for that theory.

I'm not sure why I wrote 'so much for that theory.'

I checked the oil tonight; it has been about 1000 miles since the new thermostat and guess what?

The goo is gone.

[oceanjoe89]

excllent to hear that cep. I think my thermostat is on the crap and might be causing my yellow goo issue as well

[Skoobahead]

interesting, but did you have good heat in the cabin prior to the thermostat change? My heat pumps out very well so I think my engine temp is quite normal.

[cep]

Yes, we never had any complaints with the amount of heat in the cabin. The whole thermostat thing was set in motion by a 'cooling system problem' code (P1296 in OBII language). But other symptoms were pointing to an engine running colder than normal--the goo on the oil filler cap, oil that had a smell of gasoline, and poor mileage. If the engine doesn't get warm enough, the condensation never gets cooked out of the oil, hence the goo. If the engine never gets warm enough, the computer richens the mixture, hence the poor mileage and gas in the oil.

The thermostat seems to have fixed two out of three. The goo is gone and the oil no longer smells of gas, but the mileage is still lousy. Maybe a little better, but not good, 23mpg or so. But it had done as poorly as 16 mpg on one tank that I checked.

[LadybugEwa]

For the mileage I'd look at the MAF and the pre-cat O2 sensor. That's assuming you've changed the fuel filter already.

[Skoobahead]

Wow.....This goo thing is unbelieveable.The past few days I've put 150 miles of mostly highway driving since I completely cleaned hoses and valve cover area. Temps have been in the teens.
I pulled hoses off to check today... GOO is starting to grow in hoses all over again! Valve cover area under oil cap saturated in moisture.
This is while using Synthetic oil so the theory that Synthetic stops the goo is not true.
Very strange indeed. Car run flawlessly with mileage around 25.
Just plain wierd.

[cjspack]

Happened to pull off my oil filler cap yesterday and noticed the yellow goo and thought it might be something serious. When I pulled up the forum and saw all you guys w/the same problem I was relieved. This car does go on some short jaunts and it has been really cold here lately, which could account for my yellow gunk. And I, like cep, got the rusty color when wiping down the breather cap. (By the way, I am using synthetic oil.)

[racechaser]

I checked my oil, it looked like chocolate milk & smelled like gas. Car runs good, has not been getting the milage it was getting. Think a thermostat or temp. sensor would cause this?

[flip240]

that is not normal, gas in your crankcase is most likely a non-operational PCV system which allows combustion gases to recirculate back into the intake to be burned. If they cannot be recirculated, they turn back into a liquid and mix with your oil diluting it and playing extreme havoc with your engine bearings.

if you noticed drivability issues, it could be leaky injector(s) but that might cause startup issues also.

[FarrisK]

Originally Posted by racechaser

I checked my oil, it looked like chocolate milk & smelled like gas. Car runs good, has not been getting the milage it was getting. Think a thermostat or temp. sensor would cause this?

Originally Posted by flip240

that is not normal, gas in your crankcase is most likely a non-operational PCV system which allows combustion gases to recirculate back into the intake to be burned. If they cannot be recirculated, they turn back into a liquid and mix with your oil diluting it and playing extreme havoc with your engine bearings.

if you noticed drivability issues, it could be leaky injector(s) but that might cause startup issues also.

These really should be in a different thread....

Also, to the people with the goo under the oil caps: I was always told that goo under the oil cap means headgasket work. Does that not apply here?

[cep]

Originally Posted by racechaser

I checked my oil, it looked like chocolate milk & smelled like gas. Car runs good, has not been getting the milage it was getting. Think a thermostat or temp. sensor would cause this?

The T-stat or temp sensor could cause the gas smell, but the chocolate milk look, in my experience is water, usually coolant.

Are you losing coolant? How many miles/months on this oil?