325i Heater Problem

[satvir]

Seems like i have a few intermittent problems with my heater!

1. Once the car is hot the vents don't immediately chuck out hot air (yes the heater is in the red position). Chucks out lots of cold air and take too long for hot air.

2.Doesn't work all the time on 1,2 & 3. Works when on max 4 setting and even then has "cut out" and stopped throwing any air out.

I say "intermittent" as sometimes heater does come on low settings and it has cut out on max before.

And once warm it does work as usual and chuck out hot air. But some times stone cold air!

Any ideas?

I've found this online:
http://www.e30tech.com/forum/showthread.php?t=51000

Could it be some as simple as the resistor?

[Rtaylor2208]

If it only works on 4 then usually its because the resistor is fooked due the blower having dry bearings. For the fact that yours works intermitantly cleaning up the contacts on the resistor should be a job worth doing.

Also taking the fan out and lubing it up so it runs freely.

If that doesnt cure it a new resistor is £24 from BMW.

As for the temperature issue that sounds like you may need to bleed the coolant system. Does the car run at the correct temperature i.e. the temp guage between the quarter and three quarter marks on the guage? It should be somewhere close to the middle on a colling system thats working properly.

[satvir]

It used to sit fine in the middle without having to turn fans on etc. Only recently (last few days) it suddenly shot passed the half way mark and in one instant i just shut her off otherwise would of over heated.

Today she just crept passed half way and i turned heater onto max and it came back down and stayed there. All a bit "hmmmm" for me at the moment. As coolant change along with water pump/belt and pulley was carried out in sept. oh and thermostat.

[Rtaylor2208]

Sounds like an airlock in the coolant system.

I would start with following the wiki guide on the coolant side of things, checking for leaks, air locks, a working viscous fan, flow, and making sure you have no signs of a head gasket failure.

[Rtaylor2208]

These links will help:

http://e30zone.net/e30zonewiki/index.php/Cooling
http://e30zone.net/e30zonewiki/index.ph ... nly_on_Max

[satvir]

Sounds like an airlock in the coolant system.

I would start with following the wiki guide on the coolant side of things, checking for leaks, air locks, a working viscous fan, flow, and making sure you have no signs of a head gasket failure.

Thanks for the advice mate. Hopefully just need to bleed system. As fan etc was check when water pump, timing belt etc was serviced.

Hopefully not a head gasket, as oil in water etc. Oil & water levels are good and no mayo in cap!

[satvir]

What's the role of the heater matrix in all this then?

[Rtaylor2208]

Taken from the wiki:

"The heater matrix is essentially a radiator. Fed by two pipes from the cooling system, it sits inside the cabin behind the central section of the dashboard. The amount of coolant flowing into is regulated by an electrically-controlled valve, operated from the controls.

The core itself is contained within a large plastic shell, to incorporate all of the vent outputs, the controlling flaps and a water drain, if needed.
"