Why is there tan sludge inside the oil cap?
 

I went to add oil today and the underside and top of the oil filler spout were quite full of a soft tan coloured sludge. I've never seen anything like it so I'm hoping someone here has an idea what it is.

The engine has about 4,000 km (2,500 mi) on it since since a complete rebuild.

Thanks,
Rod.

Re: Why is there tan sludge inside the oil cap?
 

It's moisture. More than likely from the change in season as the air temps warm up and a lot of moisture is in the air and makes it's way into the engine.
Just wipe it all off and don't worry about it :)

Re: Why is there tan sludge inside the oil cap?
 

Thanks, that makes lots of sense -- the outside temps have been up and down all winter. Good call!

Re: Why is there tan sludge inside the oil cap?
 

It's also more likely to build up with shorter trips,

Re: Why is there tan sludge inside the oil cap?
 

Man, you guys are good! My daily commute is only 7km each way, so right again!

Re: Why is there tan sludge inside the oil cap?
 

Yes you need to take it for a longer run to get the oil up to temp, to boil the water out of it.


Harvey.

Re: Why is there tan sludge inside the oil cap?
 

My Dad had a service station when I was a kid (this 50 years ago...) and I remember him talking doing an "Italian tune-up" on a customer's car -- which was to take it for a good high-speed run to clean it out.

Re: Why is there tan sludge inside the oil cap?
 

You need to do the same once in a while. :) :lol:

Re: Why is there tan sludge inside the oil cap?
 

Just got back! Beautiful early spring day, so why not take advantage?

Stopped by NAPA on the way back for an oil filter. The one I've seen recommended here -- Purolator L30165 -- is $45 so I settled for a K&N HP 4001 for half of that. Not surprising, there's none in stock but it'll be here Wesdesday. Picked up 7qts of Amsoil 5W-30 at the local hardware store, so all I need now is a hoist. :o

Re: Why is there tan sludge inside the oil cap?
 

Real men can do it w/o lifting the car.

Re: Why is there tan sludge inside the oil cap?
 

I used to know a girl who changed her own oil by driving two wheels up on the curb.

<3<3