Should I be worried? Nasty under the oil cap...

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Quattro Pete

Quattro Pete

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I checked my coolant level today and noticed it was just slightly lower than before. Then I took of the oil cap and noticed these strange looking sediments on the sidewalls. I don't remember seeing them before...

P1020460.jpg


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I've got about 4k miles on this OCI (GC 0w-30), another 1k miles to go before I was planning to do a UOA. The car has 41k miles total.

What do you guys think? I really don't like the way this looks...
 
Someone with more experience can chime in here but that doesn't look too good for a car with 41k on it. What kind of car, motor, etc...?
 
Have you been making short trips lately? Have a Dodge Durango 4.7 that gets the same look in the oil fill neck when it's cold outside or when doing short trips from condensation. 41K seems too low miles for a blown head gasket. Drain the oil and see if it looks thin or milky. I would do a UOA too just to play it safe.
 
I've seen lots of filler caps like that before even on cars without blown head gaskets. Sometimes it's just a funky design where condensation builds up. I've seen it on my sister's Daewoo and her boyfriend's Kia. But if I were you, I'd still get it checked out.
 
I've had similar and worse.

The similar was simply short trip condensation.

The worse was a cracked block.

The difference was very noticable. The worse one looked like a tan/beige goo, and there was a lot of it.

However, while this isn't an obvious problem it does cause initial concern. If I were you, I'd:

1) Clean the cap.
2) Send in an oil sample.
3) Change oil (to be cautious).
4) Keep an eye on the cap every other day while you await the return of the report on your oil sample.

Good luck with that...
 
One thing that would concern me is if you have had a sudden coolant drop. If so, I'd get it checked ASAP.
 
To answer some of the questions... the engine is a BMW 3-liter straight-six (M54B30):
http://en.wikipedia.org/wiki/BMW_M54#M54B30

As for my driving patterns, I have a 14-mile one-way commute, twice a day, in a suburban setting with lots of traffic lights but not bumper-to-bumper traffic. It takes me about 30 minutes. I would think this would be sufficient to burn off water vapor, especially that the ambient temps are in the 80s and 90s here, so the coolant gets up to temp very quickly and holds at about 92 deg. C (197F).

Visually, the coolant level is slightly down, but it may just be the time I measured it... it's hard to tell really. I guess I need to do a pressure test.

Thanks for the comments so far. Keep them coming...
 
A quick $20 engine oil analysis will tell the story. You can find several places which offer that service on the sponsors page here.
 
Quote:

A quick $20 engine oil analysis will tell the story. You can find several places which offer that service on the sponsors page here.

Click to expand...

Oh, I am definitely planning on doing that. I already have a test kit, but wanted to wait until I hit 5k miles on this oil run. I was just wondering if there is anything else that I need to do immediately, even before I send the oil for analysis.

Has anyone performed a coolant system pressure test by themselves? How expensive are such testers and where can I buy them?
 
i wouldnt wait, an oil change is cheap considering the issue you MAY have.. i would do it soon... i would rub my finger on the stuff and smell it. see what it smells like, oil, rust, coolant etc etc.. never know.

have you ever overheated the motor? or has anyone overheated it?
 
AutoZone has a loan a tool program that you could use to borrow a pressure tester, or just take it to a shop you trust. A little money spent now could prevent a bigger expense later, especially considering the low mileage on the car.

When the lower intake gasket on my Chevy went, all I had was white gunk under the oil cap. It didn't look nearly as ugly as those pics.
 
Quote:

have you ever overheated the motor? or has anyone overheated it?

Click to expand...

Not within the last 11k miles that the car was in my possesion. And when I bought it with 30k, there was no such stuff under the oil cap.
 
it is a spot where condensation can exist though.. i would swing it by a BMW place and let them look at it. or find an online BMW chat site and post there to see what they say
 
BTW - Shannow has real time data for his 330ci with the same engine that indicates it takes 10 miles in a similar climate to yours in stop and go traffic for his oil temperature to reach full operating temperature. On the highway it takes longer than 10 miles as I recall.

In the best possible case, it is likely that only in the last 4 miles of your commute is your oil at full operating temperature.

In the mean time, I would check the coolant section to identify the key elements in your g-48 coolant (I think you would be looking for high Na if memory serves), then get that UOA right away.

For instant gratification, you can go to a radiator shop. Most have a clear plastic device they fill with a blue chemical. They put this over your radiator opening (in place of the radiator cap) and allow radiator fumes to bubble through it. If the blue chemical turns red, it indicates that combustion byproducts (hydrocarbons) are in your coolant, indicating a head-gasket leak.

If it makes you feel any better, BMW's turn castrol and most other oils this color of brown pretty rapidly. Mine looks similar, but without any trace of milkiness you are seeing.

I would want to get to the bottom of this asap if I were you. I personally wouldn't wait until the end of your originally planned OCI.

Please let us know how you resolve this!
 
Do you guys think that a possible oil leak could have developed as a result of me using AutoRx? I added AutoRx a few thousand miles after I bought the car and finished my rinse cycle 4k miles ago. This is actually my first oil run after I fished with AutoRx rinse.

I know AutoRx is in high regard here, but I think there have been cases where it caused leaks...

Then again, I haven't noticed any oil loss. If anything, it is the coolant level that has dropped slightly, if any.

On the other hand, my mechanic is telling me, that the pressure in the oil system is much higher than in the coolant system, so if the two were mixing, it would be the oil getting into the coolant system, not coolant getting into the oil system...
 
Quote:


On the other hand, my mechanic is telling me, that the pressure in the oil system is much higher than in the coolant system, so if the two were mixing, it would be the oil getting into the coolant system, not coolant getting into the oil system...

Click to expand...


While the engine is running that is probably true, the oil is at a higher pressure than the coolant.

After you shut the engine off, however, the coolant is still pressurized and remains so for a while, while the oil is no longer under pressure.
 
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