Yellow/Green Goo in Oil Fill Tube

[whs]

Was messing with the car (1999 C2 Cab 64k miles no RMS issues to date) today and opened the oil fill cap and noticed a yellow/green (sorry, I'm color blind) goo (not sticky, but the consistency of say hand cream) inside the filler tube. My first thought was this isn't good and opened the coolant cap. No sign of anything unusual there. Fluid looks clean and clear. Is this normal? Anything else I should look for? Thanks for your help.

Will

[horseman]

Was messing with the car (1999 C2 Cab 64k miles no RMS issues to date) today and opened the oil fill cap and noticed a yellow/green (sorry, I'm color blind) goo (not sticky, but the consistency of say hand cream) inside the filler tube. My first thought was this isn't good and opened the coolant cap. No sign of anything unusual there. Fluid looks clean and clear. Is this normal? Anything else I should look for? Thanks for your help.

Will

This can be bad or not so bad. If the car has been sitting for a long time in the winter or in a high humidity situation then goes through a big temperature change the moisture in the air, and oil in the crankcase can reach the dew point and cause a very small amount of what you see in the filler tube. It would still be wise to have a good tech check it out. A clean dip stick and clear coolant is a good sign. On the other hand, If there is a significant amount, that could be several things, none of which are very good. Good luck.

[GranburyChuck]

I have noticed the same thing. My oil is clean, nothing in the radiator reservoir. I seemed to have noticed it when weather got cold. So as Horseman says may not be any problem. At first I was concerned about the air oil separator but I only have a light smoke on start-up. So I'm hoping it is just the temperature change.

[2Fast996]

I have similar observations. Sent off an oil sample for analysis and all was well :thumbup:

[1999Porsche911]

Chances are, if the sludge is appearing in your oil fill tube, it is accumulating in other areas of your engine. To prevent this, you must bring your engine to maximum temperature for longer periods of time. There is no other way of eliminating it short of eliminating all humidity the car is exposed to. This also means you have substantial moisture in your cylinders at startup which is the leading cause of engine wear.

[whs]

Thanks for the replys. Sounds like it could very well be a weather related moisture issue. Our climate here has been crazy with temps in the 60's one week to snow and freezing temps the next and back. Is there anything that Porsche recommends to deal with this? An oil additive or something. At next oil change should I have the oil system flushed? Sounds like this may not be too uncommon of an issue. Thanks again.

Will

[1999Porsche911]

Thanks for the replys. Sounds like it could very well be a weather related moisture issue. Our climate here has been crazy with temps in the 60's one week to snow and freezing temps the next and back. Is there anything that Porsche recommends to deal with this? An oil additive or something. At next oil change should I have the oil system flushed? Sounds like this may not be too uncommon of an issue. Thanks again.

Will

You have already been told the 2 ways to prevent it. Putting in fresh oil will not eliminate it from coming back. The cause of sludge is moisture and/or contaminants in the oil. If you drive your car for short trips that do not allow the temperature to rise to normal for a length of time, you will not remove the moisture in the oil that accumulated during the last engine shut down, High relative humidity increases the amount of moisture entering the engine as it cools.

[whs]

Thanks for the replys. Sounds like it could very well be a weather related moisture issue. Our climate here has been crazy with temps in the 60's one week to snow and freezing temps the next and back. Is there anything that Porsche recommends to deal with this? An oil additive or something. At next oil change should I have the oil system flushed? Sounds like this may not be too uncommon of an issue. Thanks again.

Will

You have already been told the 2 ways to prevent it. Putting in fresh oil will not eliminate it from coming back. The cause of sludge is moisture and/or contaminants in the oil. If you drive your car for short trips that do not allow the temperature to rise to normal for a length of time, you will not remove the moisture in the oil that accumulated during the last engine shut down, High relative humidity increases the amount of moisture entering the engine as it cools.

I understand the advice that was given. That being said, you can't control the weather and don't always drive your car 100 miles everytime it leaves the garage. I will admit that there are many time that I take my car out on quick trips to the store, so I will stop doing that as often. So the question is, is there anything else recommended to help with this situation. The answer may very well be no. Thanks again.

Will

[RFM]

Condensation residues in the filler cap area are normal, it is the coolest area of the entire engine. The humidity inside the engine go's up and forms condensation in the coolest area, the residue is a chemical reaction between water and oil.

If the car have no coolant consumption there is nothing to worry about, it is a typical short run symptom. All Porsche engines with the oil filler separate from the engine have this, even the air coolers.

[1999Porsche911]

Condensation residues in the filler cap area are normal, it is the coolest area of the entire engine. The humidity inside the engine go's up and forms condensation in the coolest area, the residue is a chemical reaction between water and oil.

If the car have no coolant consumption there is nothing to worry about, it is a typical short run symptom. All Porsche engines with the oil filler separate from the engine have this, even the air coolers.

That is an incorrect statement. Not All and NOT even many Porsche's experience this problem. It also IS a condition to be concerned about if the sludge is there all the time. You may be right that the filler tube is the first place the sludge will appear, but it does not stop there. This sludge can and often accumulates in the areas of the engine where oil fumes go but flow does not exist and areas adjacent to oil flow. Coolant consumption has nothing to do with this condition as the moisture is not from the coolant but from the atmosphere. Bringing the engine to full operating temperature for coolant and oil on a regular basis will eliminate the problem.

People who drive short trips on a regular basis and do not bring the engine up to temperature and live in humid climates have a greater risk of sludge and subsequent engine damage.

[1schoir]

Condensation residues in the filler cap area are normal, it is the coolest area of the entire engine. The humidity inside the engine go's up and forms condensation in the coolest area, the residue is a chemical reaction between water and oil.

If the car have no coolant consumption there is nothing to worry about, it is a typical short run symptom. All Porsche engines with the oil filler separate from the engine have this, even the air coolers.

That is an incorrect statement. Not All and NOT even many Porsche's experience this problem. It also IS a condition to be concerned about if the sludge is there all the time. You may be right that the filler tube is the first place the sludge will appear, but it does not stop there. This sludge can and often accumulates in the areas of the engine where oil fumes go but flow does not exist and areas adjacent to oil flow. Coolant consumption has nothing to do with this condition as the moisture is not from the coolant but from the atmosphere. Bringing the engine to full operating temperature for coolant and oil on a regular basis will eliminate the problem.

People who drive short trips on a regular basis and do not bring the engine up to temperature and live in humid climates have a greater risk of sludge and subsequent engine damage.

I think that you and RFM are essentially in agreement. RFM was pointing out that if the moisture is not being contributed by the cooling system, then there is no major problem, as one can then conclude that this condition is a result of "short runs" ("...typical short run symptom") and longer runs would eliminate the problem.

I have experienced a similar condition when I just take short drives.

Regards, Maurice.

Edited February 1, 2008 by 1schoir

[Jon996]

Just another confirmation note. This happened to me too as the weather got colder in MN. Nothing all summer, but a couple of short trips and the yellow goo. I did stop by the dealer, who confirmed a normal response to cool weather.

[GranburyChuck]

Thanks Jon996, I assume it is the cooler weather too. I am here in north Texas and one morning it is 19F and in the afternoon 68F. I drive about 50 miles one way to work on highways so speeds reach close to 80 mph (ooopss don't read that). My temperature gauge is well within normal range every time I get the car onto the freeway. So I feel pretty confident it is related to the cooler air temperature. Never saw it in the summer. This car is my daily driver to work and usually not used on the weekends so every trip is a long distance high speed? trip.

[JohnJStewart]

My car had it and I don't think it's an issue although these cars probably do need a good warm up from time to time.

[wvicary]

From my VW days I seem to remember that the oil temp must be something like 80C before it can start to burn off the moisture in it.

[Scouser]

I have had this in my car for the last 5 years in about 60,000 miles. I change the oil every 5000 miles minimum.

I see it prety much every time I go to check the oil. Car still runs great.

I am not sure if its normal but I don't think it;s a problem.