[lowrydr310]

I searched and read numerous posts about the issue of no heat, but couldn't find any definitive answers.

I have no heat in my car. Not that I need it, but there are a few days in January and February where it would be nice to warm up a bit. I've read about clogged heater cores or improperly functioning heater control valves but didn't see any real solutions.

My engine is up to operating temperature (205+), the selector between the vents is on the red setting, temperature is turned up all the way, AC is off, and the blower moves a nice volume of air, yet it's the same temperature as the outside air.

The coolant was topped off and not low, no leaks in the system (not before tonight when I replace the oil filter housing gasket and the coupler from the thermostat hose to the cylinder head split). My radiator and thermostat were replaced in November so it's not likely the thermostat is bad. My car gets to operating temperature somewhat quickly and maintains normal temperatures (viewed in INPA).

How do I start diagnosing this?

[ptpending]

did you ever replaced you engine pump ?

[Big Mexican Women]

clogged heater core. expensive to fix. living in LA I wouldnt bother

[e90yyc]

Originally Posted by Big Mexican Women

clogged heater core. expensive to fix. living in LA I wouldnt bother

^

If you’re feeling brave and patient, here’s another members excellent DIY:

https://www.e90post.com/forums/attac...6&d=1331031264

[ptpending]

it is possible to wash out heater core without removing heater
simply disconnect heater pipes from engine compartment, connect external pump with reservoir with prepared mix and this can help
my friend on e83 with N52 did so and it helped

[e90yyc]

Originally Posted by ptpending

it is possible to wash out heater core without removing heater
simply disconnect heater pipes from engine compartment, connect external pump with reservoir with prepared mix and this can help
my friend on e83 with N52 did so and it helped

Good advice.

Silly question, but what causes this? Corrosion in system? Impurities, or buildup of some kind?

[Big Mexican Women]

Originally Posted by e90yyc

Good advice.

Silly question, but what causes this? Corrosion in system? Impurities, or buildup of some kind?

generally caused by corrosion. OP, what did you use to top-up your coolant with?

[lowrydr310]

Originally Posted by e90yyc

^

If you’re feeling brave and patient, here’s another members excellent DIY:

https://www.e90post.com/forums/attac...6&d=1331031264

"Please allow for an entire weekend to get this done (even with a helper). You never know if/when you will run into a snag. It took me approximately 16 hours to get this done and I had a helper."

Yeah.. not looking forward to that. I'll try the flush first.

Originally Posted by Big Mexican Women

generally caused by corrosion. OP, what did you use to top-up your coolant with?

I was afraid this question would be asked. I didn't add any coolant as it wasn't low, I meant that it was full and set at the appropriate level in the expansion tank. The previous owner of my car had some cooling system work done last year and there is green coolant in the reservoir. The repair receipts have no specific indication of what coolant was added. I see where you're headed with this, mixed coolant types could have caused corrosion or a clog.

I'll be losing a bit of coolant when I replace the coupler from the head to the thermostat, so I will first try flushing the heater core. At the same time, I think I'll flush the entire system with distilled water and then replace with the proper coolant.

[ptpending]

Originally Posted by e90yyc

Good advice.

Silly question, but what causes this? Corrosion in system? Impurities, or buildup of some kind?

if you perform such flushing as i described before you'll see what it can be, because i truly do not understand how aluminium core can corrode when using bmw coolant

[e90yyc]

Originally Posted by lowrydr310

"Please allow for an entire weekend to get this done (even with a helper). You never know if/when you will run into a snag. It took me approximately 16 hours to get this done and I had a helper."

Yeah.. not looking forward to that. I'll try the flush first.




I was afraid this question would be asked. I didn't add any coolant as it wasn't low, I meant that it was full and set at the appropriate level in the expansion tank. The previous owner of my car had some cooling system work done last year and there is green coolant in the reservoir. The repair receipts have no specific indication of what coolant was added. I see where you're headed with this, mixed coolant types could have caused corrosion or a clog.

I'll be losing a bit of coolant when I replace the coupler from the head to the thermostat, so I will first try flushing the heater core. At the same time, I think I'll flush the entire system with distilled water and then replace with the proper coolant.

Agreed. Sounds like a not-so-fun job.

Sounds like PO used the wrong coolant. Good call on the flush. Hope it helps.

Option 2 would be to find some heated seats (or just seat: fuck the passenger) and swap them in. I'm sure it'll be impossible to find them since you're in Cali, but I once had blower motor issues when temps were hovering around 0 degress F, and the heated seat made a world of difference. I'm sure with the temps where you are, this might be enough to stay comfortable.

Ghetto, sure, but it would help and take no time compared to doing the core.

[robthewrench]

Originally Posted by e90yyc

Good advice.

Silly question, but what causes this? Corrosion in system? Impurities, or buildup of some kind?

Corrosion. All coolant types come with corrosion inhibitors to slow the rate of corrosion of the metals (iron / aluminum) in the cooling system. The problem is that these inhibitors get used up / worn out over time. This is one of the reasons a coolant change is part of the maintenance schedule.

You could put perfect BMW coolant in the system, but if you don't change it in the next 10 years, you'll start having corrosion issues. Change your coolant every 5 years or so.

In addition to corrosion, oil contamination is fairly common on the e90 platform due to the leaking OFHG.

As a note, I don't recommend a flush as this can loosen build-up in the block and send it into the heater core, where it will plug up the heater core.

[GMe90]

I have the same issue in my car. I had the dealer do the flush (which is apparently the recommended fix, and it didn't really work). Probably the only remaining option is to replace the heater core, which is too expensive. So I rely on my heated seats. While the auto heat function does not work, after the car engine heats up, if you mess around with the controls a little bit (crank up the heat manually and aim the air to your face), you can sometimes get some warm air to come out of the vents. Not much, and it typically does not work when the temperatures are really low (in the teens). I also bought a small portable car space heater. It's not great but can keep your hands warm at least. If it's really cold outside, I just keep my coat on while driving.

I am curious to see if this heater recall will improve anything.

[lowrydr310]

While replacing the hose from the thermostat to the head, I did two drain and fills using just distilled water (to get all the old green coolant out so I can fill the system with the correct BMW coolant). I now have some heat! It isn't as hot as it should be, but there is definitely heat.

Perhaps there is hope and a proper heater core flush can resolve it.

[330istocknot]

I had this problem on my e46, took out the heater valve and cleaned it up! Heat started coming out after that. I made a video long ago, you can see here