E34 M43 - 1995 Overheating though everything swapped

[Martin - Denmark]

Hi. Hope somebody can help me with this problem.

I have a BMW 518 M43 from 1995. It keeps overheating after short time...

Ive swapped the following:

Termostat
Radiator
Radiator hoses
AirCon valve
Waterpump

Everytime it overheats the Radiator and Termostat is cold....

I think the headgasket "packing" is faulty, but that shouldnt cause it to overheat should it ?

Hope somebody can give some good advise.

cheers..M

[Rory535i]

I know it may sound stupid, but did u make sure the thermostat is in the right way round? I did a head job on mine recently and I was working really late in the night and put the damn thing in back to front and never noticed! Couldn't work out why it kept overheating. Put it in the right way and everything was fine.

[Brandon J]

2 other things to consider are: if there are any air pockets in the cooling system b/c the coolant will not move around and cool if there is air trapped. It is very important to bleed the air out of the coolant. Also, check the temp sensor on the radiator.

[TC535i]

Heater core?

[632 Regal]

I vote along with Brandon on an air pocket!

[Unregistered]

Agree with Brandon. I own similar car as Martin and swapped the same thing (except the a/c valve). Shouldn't be thermostat because it comes as a unit with the housing. It took me several times to bleed the air out, each time between 15 to 30 min (I got tired of waiting under the hot sun). Also, don't forget what other forummers here (from other threads) said, switch off the aircond, switch on the heater to highest temperature, fan at full blast no. 4 while doing the bleeding.

[Brandon J]

One of the indicators of an air pocket is the cold coolant hose. If the return hose is either too cold or too hot, there can be air trapped. Too cold means that the coolant or air isn't being moved, thus not heated from the engine, and too hot means that there is air in the return hose and it gets hotter than the coolant.

One way to aid the dislodging of air pockets is to squeeze and let go of the hoses a couple of times every so often while bleeding.

[mike wong]

it's what the fan is bolted onto before it attaches to the water pump.
try spinning the fan by hand. they should be some/little resistance felt which slows the fan down. if it spins too freely, the clutch should be replaced.

[Martin - Denmark]

Just wanted to say thanks for all of your advise - I'll try bleeding the system again, and check the fanclutch.

Cheers
Martin

[dca]

if your radiator is cold and engine is heat, there can be deposits inside your hoses or there can be air inside your system. make front of your car is higher than rest, remove bleeding screw start your engine let it run, and adjust heater inside to the highest heat setting. add water to your radiator and wait until seeing water bubbles stop and water leakage. try this tow or three times after waiting some time( use your car and try) . I dont think this is related to gasket.