[s-cars] Detonation, HELP... (on the road)

[Joshua van Tol]

On Sep 22, 2006, at 1:33 AM, djdawson2 at aol.com wrote:
> This detonation is BAD.  We're not talking about high boost  
> stuff... I'm talking about a very audible knock when anything above  
> 0 boost is applied.  Any small grade, any attempt to pass.  You can  
> even hear the engine detonate if you simply rev the engine in neutral.

Sounds like a bad rod bearing to me. If you had enough timing advance  
to cause detonation while revving the engine with no load the car  
would be running spectacularly bad, you would be having severe  
problems just getting it to start. There would be no mistaking it.  
All your symptoms point to an internal engine problem. Check the oil,  
look for metal flakes in the oil. It will help to look at the oil in  
oblique lighting.

In any case, stop driving. The rod will eventually fail, and then  
instead of needing a reground crank and possibly a rod, you'll pretty  
much need an entire bottom end, and possibly a head if you get really  
unlucky.