I'm looking for some help on troubleshooting my buddies overheating prelude. It has a h23a engine.
The gauge peaks out sometimes when the car is sitting at idle, going up a bar every few minutes, and other times will hold at halfway. We also cannot get hot air out of his blower.
When the enine is hot, upper rad hose is hot, lower rad hose is warm, valvecover is at 70*C, upper rad hose coolant neck at 100*C, lower rad hose coolant neck 70*C, rad 70*C.
Where would I start looking? At first I thought it might have been a bad ground for the sensor somewhere, but because he has no heat that should indicate either thermostat or heater core blockage right?