Pontiac Owners Club UK

Hope someone can help point me in the right direction. My radiator fan does not turn on and my car gets very hot. Right into the red line. It is fine when moving. But in traffic it will creep up. And when I turn the engine off it bubbles and sprays out of the water tank. the water in the water tank is brown but not oily or foamy.

there are 1 or 2 relays that operate the fans (haynes manual shows locations, 1 on bulkhead, 1 on inner wing)
the ECU actuates the relays by earthing them
if you look on relay it shows which terminal is which.
if you connect an earth wire to the non powered terminal the fan should come on. if not test relay and check for power at the 2 + terminals
you could test the fan by connecting earth and power direct

Thank you John. I'll check them to see if the fan comes on.

mine did not work on this formula i got i wired mine to the ignition via a relay it now runs all the time sits at a quarter of the gauge about 170
could fit a switch for it too so it warms up quicker

got mine on an over-ride switch, but ecu would still operate mine if it got hot and I didnt turn it on

but having it on continuasly is better than not coming on for sure

Probably a good idea to do a coolant flush and refill if it's brown.

I was thinking the same thing. If the fan works then I will fit a switch. Thank you guys. I'll let you know how I get on.

gta i had it ran soon as the engine fired too maybe was chipped or something so i was told it brings it on quicker ?

my red one was mechanical crank driven ran all the time so no difference really they always go round

keep em cool i say last thing you want it boiling over. i did new anti freeze and radiator cap soon as i got this one. worth checking the cap is ok there only about £12 for a nice lever pressure release us one from ebay and they look cool too

I am going to flush the system this weekend, thanks Banker.

thirdgen wrote:gta i had it ran soon as the engine fired too maybe was chipped or something so i was told it brings it on quicker ?

the hypertech thermo chip (as fitted to mine and davids) combined with the hypertech thermostat turns the fans on at about a third of gauge movement

RevEm wrote:I am going to flush the system this weekend, thanks Banker.

i did this about 2 years ago, and although the coolant never becomes truly clear again (rusty colour always returns a little) the condition of the coolant improved massively! the sludge and crap that was in mine got cleared up easily. All i did was drain the coolant from the radiator, re top up with water, let it circulate till hot, drain again and repeat until the entire coolant system is only water and no residual coolant. Once id done this, i drained again and then flushed the radiator with the hosepipe until no rust colour came out the bottom outlet.

dont forget to circulate the water with the heater and blower on maximum to make sure the heater matrix gets flushed too!!

if you disconect the top hose, put a hosepipe in the rad. and run the engine for a while this will get a lot of muck out to start with

Also, although a lot of people have told me im wrong , I only dilute coolant by about 25% so 3 parts coolant to 1 part water and I only ever use distiller/purified water.

Thanks for all the tips guys. Its much appreciated.

I didn't get a chance to flush the system today. But did test the relay for the cooling fan. The relay need replacing. It is not showing any continuity what when powered. Changed it over with the aircon relay as they are the same. And fan now working as it should Just need a new relay for the aircon now. I'll flush the system in the week if I get a chance.

So happy I can now without it over heating.

bhm1712 wrote:Also, although a lot of people have told me im wrong , I only dilute coolant by about 25% so 3 parts coolant to 1 part water and I only ever use distiller/purified water.

I usually go 50/50 antifreeze to water,i used distilled when i had the turbo engine as i read it helps keep engine cooler than standard tap water.

50% is right, antifreeze is not as good as water for keeping the engine cool so stronger is not better

sorry guys but Ferrari use 100% antifreeze for better cooling as it cools better than water. if you have a borderline overheat situation more antifreeze works.

Big Chief wrote:sorry guys but Ferrari use 100% antifreeze for better cooling as it cools better than water. if you have a borderline overheat situation more antifreeze works.

Yes i have heard this too. Ethylene glycol cools better the more concentrated it is. Hence why the manufacturers of coolant quote the freezing temperatures and boiling temperatures on the MSDS and the more coolant you use the lower the freezing temperature and higher the boiling point is.