Milk on oil cap..

Flatsixhead · Flatsixhead's Garage

A friend of mind just bought a low mile (43K) 86 951. He said the car runs like a dream and does not run hot (temp is half way between the 1/2 & 3/4 mark) The car was bought for $8500 and had extensive service history + records from day 1.. He came home from a drive tonight and checked the oil which was a little low. When he added oil he said that it looked like a milky substance on the inside of the oil cap. When I asked him if the coolant looked like it had oil in it - he checked and it looked normal (Light green in color) I also asked him to look at the dipstick to see if he could see any milkyness in the oil that came up was negative. Anybody know what milk on the oil filler cap could mean?

rb101 · 11-28-2009, 05:59 PM

That is normal, it is condensation collecting in the coolest part of the engine. You can reduce the amount by running the car longer periods of time.

Flatsixhead · Flatsixhead's Garage

Cool Thanks.. I just called him and he is super happy!!

Z-man · Z-man's Garage

I would still dump the oil to see what's there. I had milkshake inside my oil cap, and it took forever to diagnose - finally found the root of my problem - a cracked head...

-Z-man.

KrazyKarl · 11-28-2009, 08:55 PM

I had the same issue as z-man, but there was foam on the cap and at the bottom of the AOS as well as foam on the ball of the dip stick

Flatsixhead · Flatsixhead's Garage

KrazyKarl - What's the AOS? I will call him right away to dump the oil..

KrazyKarl · 04:16 PM

sorry, AOS is the air oil seperator. It's the plastic piece on the back of the engine the oil is poured into. When I dumped my oil I didn't get any separation, it wasn't until I took the valve cover off and saw the crack and a sea of green from the coolant that I knew what the problem was.

Here's what it looked like

porschehuh · 12-01-2009, 05:06 AM

i had the same prob, 10 miles after a $1400 head gasket, my car started to smoke really bad and i had the milky oil, my mech said i had a cracked cylinder, $2800 later i had a 63000 mile shortblock

Flatsixhead · Flatsixhead's Garage

He went from happy to sad in under 4 seconds... Not sure what to tell him but I hope that the milk on the cap is normal condensation. He said that the oil looked normal (a little dirty but not milky or foamy) I feel bad because he bought it after getting a ride in the Silver Bullet.

FRporsche · 12-01-2009, 09:59 PM

If you see milk under the oil cap it's because you need to pour motor oil in there, not milk. Well at least use whole milk, 944s don't like the thin stuff like 1% - not enough milk pressure.

My 944 runs great, and I see condensation on the cap too. Like stated above, it's normal and nothing to worry about. One day when all the moisture is removed from the engine, it will stop (or if you rebuild/clean it). Maybe try seafoaming it and then flush it out with a few oil changes... but that's overkill, it really is fine.

banana944 · 12-01-2009, 10:29 PM

Oh please dont let these stories worry your friend, its normal.

rb101 · 01:36 AM

My suggestion:
1. Change the oil (so you know it's fresh).
2. Drive the Car (so it can be enjoyed and get the oil hot to drive out the moister that naturally collects in it).
3. Check oil (minimum weekly).
4. Check coolant (minimum weekly).
5. Drive car more.

Don't worry about the things you can't control.

DanielDudley · 12-02-2009, 02:55 AM

Unless your engine oil looks like a chocolate milkshake, chances are you are fine. It is always a good idea to check the oil often, at least at every fill up, and look at the coolant level at the same time,

Wipe out the cap and go for a long drive, and my guess is that your friend will never see it again.