skumbee

make a car over heat??????
my problem right now is the car over heats when its on drive but when i put it in N and rev it the temp. drops

WhiteWindsor

Yes they can, but you could have another problem also. Change the pulley' out and see what happens.

skumbee

hmm ok its cuz i just got the car about 2 weeks ago and its funny cuz when i put it in N and rev the engine the temp. drops
and when i drop it in D the cars temp goes up fast

chath_brick

it slows down the water pump, so yeah that could be it, but you probably have other problems as well (slowing down the pump that little bit shouldnt make a HUGE difference)

skumbee

ok soo ive checked the compression on my heads and the highes was 170lbs and most of them read 165lbs does any one know if these numbers are good??????????

67mustang302

You mean compression tested the cylinders? That's fine. Underdrive pullies make the pump turn slower can actually help with cooling in some cases, more time to absorb heat from the engine, and more time to transfer it to the radiator. Have you flushed the cooling system?

mattdel

year of the car matters here.
a bad fan clutch won't cool as well during cruising rpms, especially with a load.
free revving it in neutral will bring the temp down also with a bad fan clutch.
most of the time, a bad fan clutch will make a howling noise while its still cold.

but yah, start with swapping out that pulley for the stock one. it shouldn't matter too much, and your situation sounds like a blockage in the system rather than the pulley, but hey... start with the simple stuff, right?

skumbee

hmm how can i take care of this blockage????????
ooh and yes i meant the cylinders......
and well if you say that underdrive pulleys dont make much of a dif. then i wont remove them
the guy that sold it to me said that it needed a fan clutch but then again alot of people checked it out already and they say that the fan clutch looks good

rocketrotary

First make sure your radiator is clear of debris. Then drain your cooling system and flush it. a fan clutch is not expensive, nor is it a difficult part to change, so you might want to go ahead and do it anyway. Just my $0.02

Baddog

Put a lower temp t-stat in it. Is it warm where you are?