If my coolant tempurature reachs above ~220*, my engine will start pings consistently, not hard, but consistant. Even if I run the fan, to cool it back down it'll keep pinging. I am going to drop a 180* thermo in, and wire up a manual fan switch to ensure I dont reach 220*, but I dont think it should be knocking like that. Why would it do that? Maybe I have carbon build up or something??

 

My 91 305 TBI pings considerably more when it is hot even when I keep the fan on by setting the climate control to AC (AC not operational). I have replaced the O2 sensor and verified that the EGR valve is operating correctlly. I not sure what to do next. I have even considered changing the spark table in the PROM.

 

Yeah, my EGR gets stuck sometimes, and if it gets over 220* it'll ping till you let the heads cool down. I am gonna wire in a manual fan switch, and also I am gonna spray some water into the throttle body....

 

I forgot to mention I slowly poured about a cup of water through the throttle body when running the engine at 3000 rpm thinking the head had carbon deposits. No black clouds came out the exhaust like some people have mentioned on the board and it did not help my pinging at high temperatures.

 

well first off it dont mean **** how much your fans are on inless you get a different t stat and only a combination of the two will provide a cool engine. the 180 sould help a lot but still will not make too much of a diff figuring the fans turn on at such a high temp so what you have to do is either put a manuel fan (why?) or put in a different fan switch that will turn it on at a sooner temp and you will not have to worry about it at all and will not wear your fan motors as much with them being always on or saving your engine because you forgot to turn it on and put in a lower t stat in. i found a 160 work great for me but i live in FL little south from you so either a 170 or a 180 is prolly going to do you good. if you still have a problems there is something wrong because i am still running that set up with stock radiator with those simple mods with my mods and i run 175 if not a little cooler

 

Well some of ya are right on with the cooling. Am willing to bet that you are using 87 octane gas and the timing is bumped up a bit right?

My car goes to 220* with 6* of timing and 93 octane and just barely detonate cause I have the car tuned arround 180*

So start using some good gas and change your fuel filter for good measure.

Kat