I havea 95 Intrepid 3.3L with 215,000 miles. The car is still in excellent condition due to religious maintenance on it, but it's getting old.

I've had the same problem on a couple high mileage vehicles and am trying to work this out..... and would like some ideas.

The engine has started detonationg under a heavy load (up hill) in O.D. and even in 3rd gear on a very steep hill. I run and have always run 87 octane BP/Ameco gas. The temp is about 1/3rd (if accurate), the ignition system is about 10,000 miles old and it started this before the new parts.
The plugs look good with a normal color and I still get about 32mpg.Higher octane gas doesn't seem to help much, neither does the temperature outside summer/winter. Any ideas?

I figure (maybe) that due to carbon buildup on the top of the piston, it increases the compression ratio over time. No?

I could:

run higher octane gas (which I am going to try 93 octane on my next fill-up)
try a colder spark plug
run a cooler thermostat
redard the timing, isn't it computer controlled?
Live with it until my engine grenades.

 

Well, this forum appears to be dead.

Any links that can tell me how to set the timing? My google searches turned up null.

 

For the record, it was a faulty O2 sensor.

 

yea, I know the feeling! It is rather dead. I have been away for a bit, and I'm not seeing too many others giving input. I am about to quit myself, I only hang in because I think maybey I can help someone. If you find a more livley fourm, let me know.