Yellow slime on oil cap and neck...

While changing my oil this afternoon, I found the underside of my oil cap and the fill neck covered in a yellow slime. I was immediately worried about a blown gasket or leak somewhere in my engine. But after further research, I found that it's common for vehicles in the winter that drive mostly short distances. Apparently, condensation forms at neck and cap but the oil or metal up there doesn't get hot enough to burn off the moisture.
Anyway, I wiped it off and continued.

I live in western pa and mostly drive 4mi to work and back each day. I need to get it out and running more often I guess. I use it every day but only put on 4,000 miles in 8 months.

The oil from the reservoir looked fine.

Any other suggestions?

 

Probably just condensation and such.

 

It's sludge. Happens durning colder weather and short trips because the engine doesn't heat up enough to burn the water/condensation off...

 

change and inspect oil to be sure. thats more than i am used to seeing

 

If it is that bad, you probably have either a cracked head or a bad head gasket. Mine wasn't even that bad and the head was cracked...

 

Take a longer drive once a week to give her time to get good and warm to burn the condensation off. If you are really concerned about your head gasket, take an oil sample and send it in to get checked.

 

It's normal, mine does the same thing.

 

Longer drives. Short run cycles are hard on your engine. Ive seen that sludge on lots of 4runners/2nd gen tacos, it's normal.

 

It's normal especially with the colder weather we have been getting lately. This is more common with these plastic oil tubes compared to the aluminum ones which can warm up faster.

 

Good reason to conclude it has nothing to do with a cracked head or bad gasket.

No big deal, search "oil cap", this topic comes up every week.

Edit: I did the search and it comes up almost every day, sometimes more than once a day.

 

i got the shorter tube that is for the 5.7L tundra and i almost never get the slime anymore. the FJ 4.0 gets an aluminum filler tube also

 

I was concerned about this because shortly after buying my '07 i noticed sludge. I wiped the cap and changed the oil. Since then i haven't had anymore milky yellow stuff!!

 

Don't worry about it OP. Do you drive a lot of short trips? If I do a lot of highway, I don't get that. If I do a lot of short trips, I do get some moisture under the oil cap like that.

 

Yeah I see that all the time when i opened up the cap to put the oil in when i do service on the truck...I do run a lot of short trips especially as a volunteer firefighter..that explains why its doing it..since ive never had an issue with the engine im assuming its not that big of a deal..i ussally wipe it off before new oil goes in...

 

Seems like a lot to me? But it does happen in the winter.

 

why not just change the oil to be sure? better safe than sorry kindof thing. if mine looked like that i would sh*t

 

First time I saw that was on my motorcycle. I posted on the ducati forum and people said the same thing about condensation.

I changed my oil with Mobil-1 full synthetic and the filter, and I do see it on short rides where I dont let it get up to full operating temperature for a while (like going to the store or somewhere close), but it is drastically reduced since when I got the bike used from the guy before. All due to new oil (and probably removing water that was in there I suppose).

 

It might be normal for short trips but I sure would not want that shit in my engine. I would start with an oil/filter change and maybe take longer trips more often even if it means driving around just wasteing gas. Hows the PCV?

 

situation normal

 

Went to do my first oil change since buying my truck. Opened up the oil cap and about my pants. Fortunately I thought quick on my feet and checked TW! It makes sense too since a little water in oil will make it turn a milky color.