How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask internal88 Your Own Question
internal88, Technician
Category: Audi
Satisfied Customers: 2574
Experience:  I have been repairing Audi vehicles for over 15 years. I specialized in German diagnostic.
Type Your Audi Question Here...
internal88 is online now
A new question is answered every 9 seconds

I have a slight amount of sludge on the inside top of my

Customer Question

I have a slight amount of Brown sludge on the inside top of my header tank and on the inside of the filler cap. Car only covers approx. 3000 miles a year and the last time I took the filler cap off was about 4 years ago.
Submitted: 1 year ago.
Category: Audi
Expert:  internal88 replied 1 year ago.

Hello, I'm Brandon - Audi tech.

The brown sludge has lot to do with short trip interval.

When was the last time you have an oil change?

Typically the PCV valve is clogged or dirty which build up the brown sludge.

Expert:  internal88 replied 1 year ago.

It looks like this in the above link. It cost about $280.

Labor is 1.4 labor hours.

Please rate me positive for the prompt service, thank you!

Customer: replied 1 year ago.
I think you misunderstood me, header tank as in coolant tank.
Expert:  internal88 replied 1 year ago.

Ok, I got it. That will be different. It sounds like a cylinder head gasket damaged.

There are two test you could confirm if is the cylinder head gasket. Will you be doing the test?

Customer: replied 1 year ago.
What is the test?
Expert:  internal88 replied 1 year ago.

1. The easy fast test is to start your engine and see if there is bubble coming up in the coolant tank. If you see lot of bubble that means the head gasket is damaged. Also if you see heavy white smoke from the exhaust. That is also an indicator.


There is a kit out there to check if there is combustion gas leak inside the coolant system.