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Milky, white paste on oil cap and filler tube

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Hi, first post....been lurking for awhile

 

My problem is just as the title states. I have a 1996 Legacy Outback 2.2L. I drive ~20 min everyday one way to school on the highway and just started to notice a white paste like substance in my filler neck and my oil cap. I did check the dipstick, and that shows no signs of whiteness. What do you guys think this is. It has been getting cold around these parts, but as i said - I drive highway+ speeds ~15min one way everyday.

Welcome to the forum.

 

The "white paste" is an oil/water emulsion, kind of like mayonnaise. Hopefully, it's just from moisture condensation due to the weather conditions. Sometimes this is PCV system related. Occasionally, it's the symptom of the beginnings of an internal head gasket leak, but usually there will be other signs at the same time if that's the cause.

How long since your last oil change? As OB said-this is a sign of condensation in your oil,it could be because of old oil and cold weather. check your PCV and replace if needed,it should help remove natural moisture build up.Have you checked your antifreeze/ radiator lately for signs of oil?

Replace the PCV valve.

 

Change the oil more frequently. Same with the air filter.

 

Otherwise its normal, but something you can reduce by doing more frequent oil changes.

 

The engine oil takes two to three times longer to heat up then the coolant does. What is happeneing is the oil isnt getting hot enough on your short trip to burn off condensation.

 

 

nipper

  • Author

The oil was just changed. I change the oil just about every 3,000 miles since I owned the car (2yrs). The coolant is fine, level hasn't dropped noticeably. I did run seafoam thru the fuel last tank, so ?? I replaced the PVC last year with subaru oem...but that doesn't mean it isn't bad/clogged...

 

So...? go ahead and replace the pvc?

 

Thanks for the replies btw

okay-well if the oil was just changed some questions. How long have you been finding the crud on the cap? Is this the first time,has it been getting worse over the course of oil changes? PCV's usually last longer but if you've got "extreme moisture" build up then you may look at it and see if it has the same crud on it which could be a bad sign. Although you are having someone change your oil next time ask them if it seems watery or cloudy or observe the oil dropping yourself. are you experiencing any driveabilty problems,over heating or heat loss?

  • Author

No problems in driveability....(and the oil is ~500 miles old btw). I change the oil, so I'll check next time. I should also mention that I took a ~2.5hr all highway trip on this new oil. The crud seemed to start once I started to get cold, it's a pretty thick coating on the cap. I'll try to get a pic tom. although you probably wont be able to notice the thickness.

 

So if there is crap on the pcv, then what kind of problem do I have. Am I looking for chunks of black stuff, cause I saw that when I changed it last time.

 

What does the air filter have to do with this? It's only a few months old, but it was a cheap puralator one.

Well since you change your own oil you would notice the buildup.If it was me I'd clean off any residue and then go on a very aggressive drive,then check the condition of the oil cap.You have not mentioned if this is a one off occurence which we need to know.

The air filter determines what gets down below and is very important,you don't have to go Subaru but don't go cheap either

  • Author

Well I noticed the crud on the cap...changed the oil...drove 2.5hrs at highway speed...looked at the cap 4 days after the trip and saw crud again, on the cap (and filler neck).

 

I am going to replace the pvc, it is cheap enough. Just unsure if that will solve my problem. What does black chunky stuff on the pvc indicate?

Well I noticed the crud on the cap...changed the oil...drove 2.5hrs at highway speed...looked at the cap 4 days after the trip and saw crud again, on the cap (and filler neck).

 

I am going to replace the pvc, it is cheap enough. Just unsure if that will solve my problem. What does black chunky stuff on the pvc indicate?

 

 

PCV

 

thats carbon from combustion which is normal.

 

How many miles are on this engine.

If the seasons changed on this oil change (60's to 30's) you can get condensation.

 

How tight does the oil fill cap seal?

 

Does the old PCV rattle when shaken? Can you blow through both ends? If its not closing, it can draw fresh air into the crankase and cause what your seeing.

 

How old is your t-stat?

 

nipper

The other thing to look at is the hoses running to the PCV valve. The hose that hooks to the valve goes to a T, one hose runs up to the air intake tract, and a 3/4" hose runs straight down to the block. Remove this hose, the T, and the PCV valve hose, and clean them thouroughly. I've found them to be restricted by carbon gunk fairly often.

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