Hi, I have a 94 Honda accord LX with a f22b2 engine. It only overheats when i drive it on the highway at high speeds. I can drive all day long in and out of traffic with out it heating up over normal temperture. I have replaced the thermostat,water pump, timming and water pump belts,radiadtor fuild, bled the air from the system,replaced the radiadtor cap, replaced the head gasket and had the head tested for cracks and redone. both fans are running, replaced the entire exhaust system. there is no water in the oil, no oil in the water and no water comming out of the muffler. It does not leak any where and it does not use up any radiadtor fuild. It only overheats at high speeds when I pass someone for example on the highway and then it gets hot and stays hot until I stop the engine, then it runs fine again at normal temps. What I missed? No ones seems to know. The only thing I haven't changed is the radiadtor and senors. Thank you Robert

 

Bad temp sensor or temp gauge? Short in the wiring?

 

I thought that could be the the problem at first, but the engine had got to the boiling point once prior to changing the head gasket. It had the exact same overheating problem after changing the head gasket and head work. I am now thinking that the head gasket was not the problem or it was caused by the radiadtor not flowing enough water at high speeds to keep the engine cool. the radiadtor is the original and has appox 200,000 miles on it. I put a new one in today and I'll try it out tomorrow and see if that solves the problem. I'll post the result. hopefully it will work and this info will help some one else. Thanks Robert

 

maybe the fluids in your radiator are no good...long shot but what oil are you using?

 

I had replaced the cooling fuilds and that didn't solve the problem. I ended up pulling out the radiator witch looked good but had the inside clogged up with build up. I couldn't tell untill I pulled it out and emptied it to look inside. I put a new one in and the problem was solved. I think it's what caused the head gasket problem to begin with. Thank you