Heating and overheating issues

Post Mon Jan 20, 2014 10:25 am

Hi,
I have overheating issues with my 91' 325i convertible since I bought the car. Needle goes 3/4 way and stays there. I have changed thermostat, radiator, fan cluch. Now it settles between 1/2 and 3/4. Sometimes it goes to 3/4 but never to red. Other day I noticed that heater only blowes worm air at passenger side. Today when needle gone 3/4 I pushed car hard and it came back just hair over 1/2 mark and warm air started blowing both sides. After driving car for another 10min temp settled between 1/2 and 3/4 witch is still too high. Any ideas? Please help!!!

Post Mon Jan 20, 2014 10:31 am

First thing to check is that the heater pipes are connected the right way around at the bulkhead in the engine bay. The hose that comes from the back of the cylinder head connects to the lower heater pipe.
Second thing to do is to remove the instrument cluster and check that the small nut on the back of the casing, right behind the temperature gauge, is tight.

Post Mon Jan 20, 2014 11:22 am

Just checked the hoses and they are correct .

Post Mon Jan 20, 2014 12:04 pm

Pipe from the back of the head to the lower heater pipe?

Post Mon Jan 20, 2014 1:35 pm

Both heater pipes in correct order and good condition

Post Thu Jan 30, 2014 4:42 am

Any more ideas?

Post Thu Jan 30, 2014 7:22 am

Brianmoooore wrote: Second thing to do is to remove the instrument cluster and check that the small nut on the back of the casing, right behind the temperature gauge, is tight.

^^^ Did you look at this?

Post Thu Jan 30, 2014 9:14 am

Did you bleed it

Post Fri Jan 31, 2014 2:09 pm

Temperature gauge is OK. Removed water pump today turn out its faulty. Will put new one tomorrow hopefully it will solve all the problems. Fingers crossed

Post Fri Jan 31, 2014 2:58 pm

Just curious...what part of the pump is faulty ?

Post Sat Feb 01, 2014 2:13 pm

bdx wrote:Just curious...what part of the pump is faulty ?

Presumably the rotor loose on the shaft or broken up, depending on type.

Post Sat Feb 01, 2014 4:23 pm

Rotor was loose. Put car together today. Bleed it. Now heater blows warm air just after few minutes and no more overheating.

:F