Author Topic: need help! (Read 2690 times)

91318radmobile · « **on:** September 08, 2010, 08:52:27 AM »

ive posted in a different section to no avail but im desperate for help so i'll try here, i have a 91 318i w/m42
the car overheated and warped the head, that issue was resolved with a milled head, new head gasket (and all other gaskets) and i also attacked the cooling system and replaced everything i could while deleting what i could
problem: the car is still overheating, it takes 15 minutes or so when idling but when driving happens in maybe half that time
i know my fan clutch is good but my aux fan never comes on(not sure if these would even be the culprit)
i have bled the system correctly, multiple times with no luck

if anyone has any tips/tricks/advice it would be appreciated
im new to these cars but im not an idiot so please do not reply as if i am

monko141 · « **Reply #1 on:** September 08, 2010, 09:17:45 AM »

Did you replace the coolant diverter tube under the intake? I pulled one that had a piece of plastic in it.

91318radmobile · « **Reply #2 on:** September 09, 2010, 10:15:58 AM »

everything was replaced/checked cooling system-wise, coolant is flowing, everything seems fine but it still gets hot

YetiX · « **Reply #3 on:** September 09, 2010, 10:35:57 AM »

Have you checked the radiator itself?

DesktopDave · « **Reply #4 on:** September 09, 2010, 01:49:04 PM »

Since you never see the aux fan run, fix that first. Check the fanstat switch on the top of the passenger side of the radiator. Jump the terminals inside the wiring connector to see if the fan comes on at all.

If necessary, boil the fanstat in a saucepan & test it that way. Relays also can cause trouble, and the aux fan itself (or the large resistor clipped to it) sometimes goes wrong.

If you're still having an overheating problem, get the system pressure tested up to 15-20psi. Any severe pressure leak will cause overheating regardless of how new everything is.

Check the heater core too. When my BMWs overheat, I always put the heater on high...on one of my cars that made it worse. Finally figured out that there was a bad o-ring on the valve inside the car! Leaks in the heater core can be concealed by the HVAC heater box, it drains out by the transmission (hard to see but easy to small).

Also be sure you have the fan bolted on the right way. It can be bolted on backwards, believe it or not. Doesn't work as well that way...

91318radmobile · « **Reply #5 on:** September 10, 2010, 10:15:09 AM »

thanks dave this is the most helpful reply yet, i havent pressure tested the system because its all new but i guess it could still be leaking, and as far as the fan, i think im going to install an electric pull fan behind the rad. that will guarantee cooling