Valves and Compression

[ScottyCBoy at aol.com]

"Valve Jobs" Consist of removing the heads and regrinding the seats and valve. Over time valves and seats wear and must be remachined. More than likely though worn valve seats and valves are caused by worn valve guides, when closed, the valve hits the seat funny and causes wear. Carbon can also build up and cause poor valve sealing. Carbon can be removed by using solvents, shell blasting or fuel injection cleaner.

Audi valves and seat typically never need to be reground, I've seen several 4 and 5 cylinder cars exceed 400K miles on the original head.

I know with the turbo engines, you cannot grind the valves, as the valve head gets thinner heat builds up quicker and can result in a burnt valve. The V8 maybe similar.

Before removing the heads I would try to get the chambers as clean as possible by using other methods, such as Carbon blasting, or a good fuel injection cleaner.

Scott



In a message dated 8/4/2003 7:55:59 AM Eastern Daylight Time, "Henderson, Bruce" <BHenderson at accuridecorp.com> writes:

>
>Have a 91 Q8 and just returned from my shade-tree specialist.  He said the compression of the left side was 60, 100, 80 and 0.  He did not do the right side.  According to him, a valve job is in order.  Several questions:
>
>1. Is this, in fact, indicative of a needed valve job?
>2. If so, do I do the one valve (No. 1)?  Or the whole 8??
>3. What is a reasonable price to pay for such a job??  I assume that I don't want to go to the Audi dealer, right??
>4. The car has 180K on it, and other than the sluggishness, is in good shape.  Can I run it in this condition for a while longer??  If I do, what's the likelihood of something else going wrong??
>
>Thanks for your help.  I'm a "newbee" to the site, love my Audi and looking for some guidance.
>
>Bruce
>
>
>
>J. Bruce Henderson
>EHS Operations
>P - 812.962.5065
>F - 812.962.5413
>C - 812.499.5802
>
> -----Original Message-----
>From:   Huw Powell [mailto:audi at humanspeakers.com]
>Sent:   Monday, August 04, 2003 1:02 AM
>To: jwarner6 at columbus.rr.com
>Cc: quattro at audifans.com
>Subject:    Re: Stumped!
>
>
>> I noticed a while ago that I appeared to have a missing component on my
>> engine.
>
>> Jeff Warner
>> Galloway, OH
>> Post 11/88 200 Quattro Wagon
>> '86 GT
>
>on which car?
>
>--
>Huw Powell
>
>http://www.humanspeakers.com/audi
>
>http://www.humanthoughts.org/
>
>
>
>