Strange gunk on oil cap

[Sleb]

I change my oil every 5000km regularly and only have ever used 100% synthetic. Today when I did my routine oil change I found this gunk in the oil cap (pics attached). I have never seen this before, when I cleaned it off with a rag it felt damp. What the hell is this? Did I some how get moisture in the engine?

 

[tower]

Did I some how get moisture in the engine?

Yes

 

[m4dc0w]

Last time I saw anything that color in the oil was when the coolant was leaking into the engine. Hope that isn't your case.

-mc

 

[Pensa]

That does look like you are getting coolant into the oil. You need to get that fixed ASAP or it will ruin your engine.

I would pull my plugs and see if I could tell if it is a cracked head or blown head gasket. There is other ways the coolant can get into the oil, but I would start there.

 

[Sleb]

The engine is running smooth, no power loss, the engine temp is fine. The oil that I drained out looked normal and had no signs of water in it at all. Why would this gunk be only under the oil cap

 

[Willard]

If there's no water in the oil, it may just be excessive build up of condensation on the oil cap. I've seen this before, just not quite that bad.

 

[Sleb]

After changing the oil I run the engine for 10 mins then turned it off and I found a few small drops of moisture under the oil cap.

 

[Willard]

If your not loosing coolant, and there's nothing in your oil, there's nothing to worry about. It's all just condensation.

 

[Sleb]

My coolant level is normal, it doesn't look like I'm losing coolant...but if it's only say a 1/4 cup I wouldn't be able to tell by looking at the overflow.

 

[Willard]

You said your oil looked normal, right? Not foamy, no white stuff in it....along those lines does your coolant look alright?

 

[Sleb]

yes the coolant is normal.......no signs of oil in there at all

 

[Willard]

If everything else looks normal, don't worry about it. It's just condensation.

 

[Sleb]

Thanks for your help.........I really hope that's all it is. Why all of a sudden would you get so much condensation under the oil cap?

 

[tower]

I would check the PCV.

 

[crash594]

Do you do alot of short trips? It happens on my parents car. Mom only drives 1 mile to work round trip. condensation

 

[Sleb]

I have just started to work at a new site which is about 1.5 miles away, so overs the last 5 weeks the truck has only had short trips on it

 

[Willard]

I have just started to work at a new site which is about 1.5 miles away, so overs the last 5 weeks the truck has only had short trips on it

That could very well be the reason, as the motor probably never gets hot enough to burn extra condensation off, so it keeps on accumulating.

 

[Sleb]

I checked the PCV valve and its clean; I live in Canada and in the morning it's below 0 and the afternoons are above 0, the condensation that I now see on the oil cap is crystal clear drops (no antifreeze in there) so cold weather and short trips seem to be causing condensation in the highest point of the engine which is the oil cap. I'll keep my eye on it just to make sure. Thanks for all your help.........

 

[mkf350]

What brand oil are you using? Mobil 1???

 

[Sleb]

Mobil 1 synthetic