KevinNg2016

Hello friends,
I have a 2004 Audi B6 A4 that was overheated. The cylinder head is bad. My question is if I buy a new cylinder head, will it work? I do not know if the overheat cause any pistons damage? Do I need a new engine? Please take a look at the picture and I need your experiences and advises.

A4Audi4Fun

Hard to tell just from the pictures - assume the cylinder head was warped. It's also possible the eqivalent mating portion on the engine block is also not true/square. Piston/ring status really can only be determined by removal and inspection while everything is apart or compression test once the new head is replaced.

KevinNg2016

Thanks for the response. I took the head to the machine shop, they told me it is junk now, which mean i have to buy a new head. But I am not sure if buying the new head will work. Since the error code mentioned something about knock sensor. I do not know if the piston/ring is damage or not even like you said.

W261w261

What did you decide to do on this? If it was the first overheat, the pistons and bottom end are *probably* ok. If it had overheated other times but didn't affect the head gasket, there is some possibility of bottom end bearing damage.

The good news is the 1.8 is an old motor by now, and you can probably find a head at a reasonable price. The bad news is that the car is maybe not worth the investment at this point.

KevinNg2016

I haven't do anything yet, because I am not sure if I buy a new head and install it, the pistons or motor is bad, chances are I will be wasting my money and my time by installing and taking it apart again. What is your best suggestion? I remembered pulled out some error codes about knock sensor or ping error, this code came on after the car was overheated and cut off all the powers while I was driving on the freeway.