Re: Tightning the belt, its all in the timming.

[zm@mhcnet.att.com (Zafer Mehmood [209])]

> 
> An earlier post said that the 8 and 10 valve normally aspirated engines
> were non-interfering.  What about the 10 valve turbo (MC) engine?  I
> would hope that it's also non-interfering, since its compression ratio
> is much lower than the normally aspirated engine.

I have the 10v turbo (MC) in my '87 5000TQ. It does seem intuitive that
the lower compression ratio turbo engines would be non-interfering but
I have been told by the trusted head mechanic at the Audi dealer that
valve damage will result if the belt breaks. He has seen this happen.
Someone else here (Glen, I think) has also seen a damaged 10 valve
turbo engine in a TQC.

> 
> I'd appreciate your wisdom on this topic because my 10V turbo has 75K
> miles on it.  The dealer has told me not to even worry about the timing
> belt until 100K miles.  I'd like to believe him, but maybe he's just
> forgoing the quick buck now in hopes of a big repair bill when the belt
> breaks!
> 

I think its better to replace the belt at around 90K miles and have peace
of mind. Whether or not the engine gets damaged, you don't want a disabled
car in the middle of nowhere due to a broken belt. I had the belt on my car
replaced at 108K. The mechanic took the timing belt cover off and showed me
the belt. It had cracks on it. Got it replaced pronto. Looking back, I was
taking a chance past 90K. Its easy to pop one end of the cover off to take
a look (two 6mm inside hex screws). Watch out for a cracked or oily belt.

-----------------------------------------------------------------
Zafer Mehmood				   AT&T Bell Laboratories
zm@mhcnet.att.com			   Murray Hill, NJ