Is that mayonaise or did i drop my Sandwich?
 

Hi all apologies if this is the wrong part of the forum for this.

I was doing some motorway driving today and i got the yellow low oil light, this really pissed me off as i topped it up 2 months ago and had the oil sensor replaced (was coming on and going of just after start up).

Ok so i thought 'i have been running it a bit hard in the winter months', get new oil, pop the hood and open the cap and I SEE WHITE STUFF.

I am an EX long time MG owner and the dreaded white stuff give me heart failure, so its not caked in it but its there. On a mid milage 2002 is this cause for serious concern or just some general maintenace? coolant looks fine, except for the low oil all is ok.... new sensor is clean and clear.

Am i panicing about nothing?

Well you might want to panic a little bit since your pcv valve is going and a dealership will change you 8 hours labor to replace it. The milky nasty buildup on your oil cap is moisture entering the system via a torn rubber diaphram in your pcv valve. All the parts are under 100$ but the valve is located under the intake, which you can imagine is a PIA to get to, which it is.
if you let it go for to long then you can expect a rough start up when its cold, possibly some smoke out the exhaust.
BMW makes a tool which we call a "slack Tube" which it pretty much measures crank case vaccum. If you have a low amount of vaccum then your pcv valve will need to be replaced.
Depending on where you live I might be able to help you out and do the job for you for alot less then the dealer would charge.

so if you remove your oil cap while the car is on, and tis really easy to remove w/no resistance, then it is bad? because for me its really easy to remove, yet i definitely dont have any white stuff in my oil or oil cap, and whats this i hear about the valve 'hooting'?

get it checked out only reason for there to be white is if coolant is getting into the oil
not a cool thing but with being new to BMW's I'm not good when it comes there to start the looking I would do and oil change and check the bottom of the pan if its thick and milky all I can say is sorry and look at your head gasket

It could be just some condensation, a bit of moisture will get in from this. If you are not losing coolant then I would not be too worried.

How did the oil look when you drained it?

Bingo, you hit it dead on the spot

When oil and coolant mix up that's what it looks like

Thanks all for good answers,

BTW i live in Egham about 10 miles from the center of London in the UK

I haven't done a complete flush yet i only topped it up. I arrived home last night and it was dark and raining... and i have no garage !!! i'll have to do it after easter.

The Oil cap is a b*tch to shift so there is still pressure and there isn't alot of mayo... haven't had any rough running, even on really cold mornings.

thanks to mr antiburn i'm looking up the manual for the PCV valve, we have these great haynes manuals here in the UK,... fooooking marvelous

I'm trying to talk my way out of a dealer bill aren't i....


Cheers lads !

good luck man just don't put this off or your could really be alot worse off than you are now

Most of the times when the oil looks like mayo it's typically a bad head gasket

yep thats what I was saying if its just a little your catching it early enough not to have the head machined so get it looked at fast but I'm not sure if there is coolant flow around the intake I'm used to seeing that on the 60 degree v-6's that gm makes the 3.4 they make is notorious for the intake gasket going leading to the same thing

Hold up, there is no Mayo in the Oil, oil is fine, its on the filler cap and the rim. Could this be condensation?

if you see it under the cap you still have it getting into the oil your not going to see how bad it is untill you drain the pan most of that will settle to the bottom of the pan even if it looks ok when you drain it you still need to have it looked at look at the head gasket check to see if there is coolant around the lower end of the intake gasket and get it checked out

The reason your yellow oil light keeps comming on is due to all this moisture build up in your oil messing with the sensor. The yellow build up around the cap is the highest point that the water vapor can get to and collects there. If the oil on the dip stick looks milky all the way through then you have a headgasket or head problem. If its only around the cap theres nothing to worry about.

Only thing you need to do is change the pcv valve and connecting hoses, change the oil and filter and blow out the moisture buildup inside the level sensor. Just make sure after youve done that wipe off the build up around the cap and see if it comes back.