Heater Core Rebuild?

[bmwman91]

I am probably going to be swapping a crack-free dash in sometime soon. Since I will be in there, I suspect that my heater core is leaking somehow since I get a whiff of coolant when I turn the heater on sometimes, and there is a little coolant spillage on the firewall (engine side) where the hoses connect to the core pipes. Do I just need the 3 O-rings shown on RealOEM, or is there more I should replace in the heater core while I am in there?

Any other maintenance items that I should consider doing while I am in there?

[vpilarrt]

Could be the valve leaking.

[jlevie]

Pull the core and pressure test it and you will know whether it needs to be replaced.

[bmwm42]

Aluminum lines replace

[bmwman91]

Hmm, the little valve and lines are $$$. I guess that's just part of dealing with it?

[TobyB]

I seem to remember that the core was significantly less than the tubing, etc.
For $60, it's not a lot to change it.
On the other hand, the core itself's not a big job to change. Up to you, I guess.
They DO pop sometimes

t

[bmwman91]

I suppose that if I am going to bother then I should really consider replacing the core and tubes/valve. There's obviously some sort of leak, and all that stuff is 23 years old.

Next question...there are "aluminum inlet" and "plastic inlet" cores. The plastic version seems to be the original OEM solution. Is one better than the other / less prone to busting?

[vpilarrt]

They are both OEM.

[bmwman91]

Thanks.

So, I have noticed that the coolant smell when the heater is on happens when I rev the engine to 4k or higher. Seems like a leaky seal or crack in the core if the issue is related to coolant pressure. I suppose that I will be able to get a better idea once I am in there.

[///M42 sport]

hey do you mind posting pics? I want to get to this eventually too.

[603Racing]

I had the same issue with both of my e30's. One had the plastic inlet of the heater core cracked. The other was leaky o-rings in the connection point at the heater core.

You can do the core without taking the dash out... it's easy. Just clamp off the lines on the engine side of the firewall. Then disconnect the lines inside the car under the dash (you will need a small catch can to collect the 12 or so ounces of coolant that will come out). You will also have to pull out the knee bolster and center console ahead of time. When you're at this point you may be able to determine where the leak is coming from before you pull the heater core.

From what I've seen over the years, the valve and the o-rings are more likely to leak than the core itself.

[CorvallisBMW]

I'm in the same boat (coolant smell and suspected leak) so I'll be tearing in to the same project pretty soon. I'll try to remember to take pics and post them up in here.