i was driving home on the freeway when i noticed the temperature was almost all the way up on the gauge when i was idling (in neutral, just cruising along downhill). so i put it back in gear after the hill and gave it a little gas and the temperature went back down to normal. this kept happening as i got off the freeway.
i just did a swap to a rebuilt engine, new belts, new thermostat, new waterpump. old hoses, radiator, new 50/50 coolant, nothings leaking.
the system has been bled.
i dont know if its because maybe i put the thermostat in the wrong way.
i swapped to the same engine, just another rebuilt one. plugged everything back on the same way. could i have positioned the thermostat in a different way and cause this tho?
i didnt bleed it out, but a mechanic friend took it to his shop and he said he bled it.
also ive noticed only the smaller, right fan turns on. ive never heard or seen the larger fan turn on. dont know if that would be it. but still doesnt make sense since i would be overheating cruising down the freeway at 70 with the engine at idle.
sounds like a bad water pump to me, when you cruise at idle the pump is not spinning fan enough to get the right amount of flow, but when you raise the rpm, you get some what of a flow. know what i mean? probably your impeller is wearing out.
nevermind, i guess you changed the water pump too… um… your radiator have been serviced? could be cloggin up on you.
radiator was new when i bought the car yr n half ago, but it was never a problem before the swap. and for the first 150 miles after the swap there was no problem, this jus started happening in the past 100 miles.
when you say “rebuilt” was the engine completely disassemble and block hottank/clean, or was it just a head resurfacing type of deal?
did you get the head resurface?
try flushing out the cooling system with a cleaning solution (about 4 bucks or so)
after market radiator?? just because its new doesn’t mean it good, trust me i learn this the hard way, i had a radiator on my miata that went out less than 6 months and it was brand new when i bought it.
i guess you have a/c, since you mention 2 fans. both fans should be turning on at the same time. either gonna be the motor or the relay. try hooking the fan up to 12v (battery). if it doesn’t turn on, you know the motor is pooched.
the fact that it cools when the engine speeds raise says that circulation is good.
plus, if a water pump goes, it usually makes a pretty distinct noise