PLEASE HELP!!! Very bad pinging

[Sanchez]

I want to say first off, that I am not new to this board. I can't seem to get my password for my old screen name.

OK, so here is the problem:

I have a 94 Ex, that is pinging, overheating, and idling too high. When I first start the vehicle, it is fine. It isn't until the vehicle has been driven for about 20 minutes that the problems begin. The temp gauge and RPM's are fine. Then it starts to idle right around 1000 RPM. Next, the temp gauge rises to about 2/3 hot (it normally stays at about 1/4 hot). When it gets hot, the pinging gets louder. I really notice it when I take off from a stop, the pinging upon immeadiate acceleration is loud. One other thing I have noticed is that the whole problem starts sooner if the A/C is on. If I turn it off, it does help a bit.

Just for clarification, these are the items I have replaced in the past 4 months: plugs, wires, both oxygen sensors, cleaned the intake.

Please help!! I haver done a search and haven't found any results.

Thanks, Brad

 

[mrboyle]

When was the last time you changed the thermostat? It sounds like you are overheating. Check the cooling system for leaks, have the system and radiator cap pressure tested. If they are fine I recomend changing the thermostat and having the radiator flushed.

 

[mrboyle]

By the way the reason the engine is idling high is due to the overheating problem. The computer is designed to raise the idle RPM if the engine temp rises above a cretain tempature. The increase in RPM allows the coolant to circulate faster and the cooling fan to draw more air across the radiator in an attempt to cool the engine.

 

[Sanchez]

Good call Mr. Boyle!

I changed the t-stat and backflushed the system and it now runs fine.

Thanks!