E30 Leaks coolant while the heater fan is on

[nicklm 0]

Hi, my E30 is leaking coolant whenever I turn the heater fan on, has anyone else experienced this before? I replaced the water pump in Dec 2012.

The leak appears to be in the engine bay drivers side and not in the cabin so I don't think the heater core is leaking but maybe the pressure change when the fan is switched on is causing the leak.

Be great if anyone has any helpful ideas for me. I plan to fill the coolant back up and turn the heater on full blast to see if I can spot the leak but if any of you know anything that's likely I'd appreciate the help.

Cheers Nick.

[Allanw 1071]

Hi, my E30 is leaking coolant whenever I turn the heater fan on, has anyone else experienced this before? I replaced the water pump in Dec 2012.

The leak appears to be in the engine bay drivers side and not in the cabin so I don't think the heater core is leaking but maybe the pressure change when the fan is switched on is causing the leak.

Be great if anyone has any helpful ideas for me. I plan to fill the coolant back up and turn the heater on full blast to see if I can spot the leak but if any of you know anything that's likely I'd appreciate the help.

Cheers Nick.

Could it be leaking all the time, and the fan is pushing the coolant out somewhere when it's on?

[nicklm 0]

Could it be leaking all the time, and the fan is pushing the coolant out somewhere when it's on?

It could possibly be leaking all the time, however each time I run the heater the coolant warning light comes on, I think maybe it's leaking from the heater return or something like that? That would be the heater pushing it out I guess...

[danutt 4]

It could possibly be leaking all the time, however each time I run the heater the coolant warning light comes on, I think maybe it's leaking from the heater return or something like that? That would be the heater pushing it out I guess...

often putting heater fan on raises idle and slight increase in cooling system pressure mmmm id look for a pipe just not on tight enough or a small hole that with elevated pressure leaks

very difficult to say but where do you see water/coolant??

[nicklm 0]

often putting heater fan on raises idle and slight increase in cooling system pressure mmmm id look for a pipe just not on tight enough or a small hole that with elevated pressure leaks

very difficult to say but where do you see water/coolant??

I've had a good look and I think you're right. The small breather pipe coming out of the top of the radiator is really old and there is a bit of coolant sitting about on the top of the radiator, plan is to replace that and see how it goes. I hope there isn't a split in the top of the rad...

[danutt 4]

I've had a good look and I think you're right. The small breather pipe coming out of the top of the radiator is really old and there is a bit of coolant sitting about on the top of the radiator, plan is to replace that and see how it goes. I hope there isn't a split in the top of the rad...

how much coolant though??the level sensors arnt great mines always on water is up to full lol

[nicklm 0]

how much coolant though??the level sensors arnt great mines always on water is up to full lol

No its Definitely leaking, very slowly though. I notice a significant drop in level in the res and it normally takes at least half a liter to top back up every 2-3rd day after. I've had a few issues with the cooling system on this car and have so far had to replace the rad and water pump. Would go as far to say that the rest of the system needs something similar haha.