Over heating again!

[MrDNR]

Hi Guys,

I'd made a thread earlier (http://www.r3vlimited.com/board/show...040#post520040) regarding the overheating of my '88 320i BMW.

Well that time, I'd got the radiator completely cleant + flushed and I went ahead and changed the setting so that the fan runs on the faster setting too.

After, leaving the car for about 10 days or so ... the car has begun going over half the mark again (almost 3/4th) and I don't think its the thermostat problem ... cause on opening the bonnet, I can feel the heat.

Last time, I'd got it serviced ... the mechanic told me my water pump didn't have any leaks and worked perfectly well. Also, right now ... the fan is working when the A/C is switched on.

Uh, just before I let it for the 10 days ... I noticed quite a lot of water loss below the car, probably A/C water? However, I topped off the coolant right now ... but it doesn't seem to help much.


Any thoughts? The car drives at around 3/4th at the thermo sensor ... should I risk taking it on a 2 hour drive to a mechanic I know? .. or should I do it locally?

[porsche gt1]

three things.

Check your fan clutch. if it has failed then that could be a very good reason why you are overheating. If the car is over half way take a rolled up newspaper to it. if the paper starts breaking your good if not replace. Just becasue the fan works does not mean it is working properly.

Second do you have a milk chocolate mix in your oil? If so you could have a blown HG, this will cause an overheating situation as well.

lastly, If you just had your Rad fluid changed, maybe you have air in the system. I would crack the filler cap and run the car for a bit to try and force the air out.

[DarkWing6]

I was going to go with #3. I have had my car overheat after refilling the same way and just letting the car run it out fixed the problem.

[ZinRot325i]

I had the same problem with another (non-e30) BMW and it was just air in the coolant.

[Adrian_Visser]

run it with the coolant reservoir cap off for like 5 minutes. so which fan are you talking about anyways? you say you:
"went ahead and changed the setting so that the fan runs on the faster setting too".
which fan are you talking about? the electic fan is for the A/C condenser not the rad.
the fan between the rad and the engine is the one that performs cooling of the engine, it is a clutch fan which 'locks' up when the clutch heats up, these clutches do wear out, my prior bmw, an e28 had a bad one, its temp was fine when moving but at a stop light it would creep up into the red in several minutes, if there's air in the cooling system causing a vapor lock of the water pump the temp will skyrocket soon after you start it.

[mrLEE30]

there is a set proceedure for bleeding and just opening the rad cap is not the way!!

put your temp knob for the heating inside the car to full hot.

fill the expansion bottle with coolant , let the car get up to heat (guage somwhere around the middle) keep adding coolant until the level is steady, close the cap, then open the bleed screw which is on the thermostst housing (8mm bolt) keep this open with the engine running until no more air comes out, then close it, check coolant level. go for a short drive with heating on full.

stop the car but keep engine running, check coolant level and re open the bleed screw until no more air comes out (wear gloves as it will be hot).

if any air came out at this stage repeat the above until only water comes out of the bleed screw when its opened.

air locks in the M20 are very bad and will cause the rear two cylinders to over heat and blow your head gasket.

mrlee

[porsche gt1]

there is a set proceedure for bleeding and just opening the rad cap is not the way!!

put your temp knob for the heating inside the car to full hot.

fill the expansion bottle with coolant , let the car get up to heat (guage somwhere around the middle) keep adding coolant until the level is steady, close the cap, then open the bleed screw which is on the thermostst housing (8mm bolt) keep this open with the engine running until no more air comes out, then close it, check coolant level. go for a short drive with heating on full.

stop the car but keep engine running, check coolant level and re open the bleed screw until no more air comes out (wear gloves as it will be hot).

if any air came out at this stage repeat the above until only water comes out of the bleed screw when its opened.

air locks in the M20 are very bad and will cause the rear two cylinders to over heat and blow your head gasket.

mrlee

I was always told the other way. I like your way better. I will now try it on mine to see what happens. :)