Why does my e36 hate coolant so much?

[Clarkey]

Following the saga prior to the trackday, the coolant has continued to fall, so I guess the stat housing was a waste of time and money. I can't identify where it is going to, but until I can get some UV dye in it, why won't it take any damn coolant!?
Today I get in the car after work and get a warning, the expansion tank is way way down, so I end up topping it up using cups from the water cooler, not a good look I have to say. Drove it home via petrol station and motorway gridlock, no heat the whole time below 3000rpm, freezing in this weather! Gauge always in the middle.

Trying to top it up and bleed it out is seemingly impossible though, I fill up the tank but every time I fill it to near the top, I get huge air bubbles coming up, and it burps ALL of the water out, at which point both rad hoses are empty and only steam comes out of the bleeder. Fill it up again, same thing happens. Flooded the garage doing this.

In the end I did the best I could with the engine off and just squeezing the pipes, but still, I have heaters only with the rpm up.

I just don't understand why it burps it all out every time though. Is it possible that there is something wrong with the expansion tank thing? I noticed that a noise comes from in there when you squeeze the hoses.

I'm going to put the old stat and housing back on, ever since I fitted this new one I've had massive problems which didn't exist before. I wonder about the radiator though, maybe this is the root cause of all the problems?

 

[Clarkey]

No sealer on the housing just rubber gaskets. It's metal anyway so won't be breaking easily.
Expansion tank is built into the radnd is more complex than simply a bottle.
Coke bottle trick sounds handy I will try that thanks.

 

[Clarkey]

I think it's the heater matrix causing a problem, I'm now getting a misting on the windows even with the AC on. I thought maybe the AC had become defective so I tried knocking it off, within 30 seconds the windows got majorly fogged up. I can't really smell any coolant though, maybe just a tiny hint of the smell. I also don't have any dampness in the carpet, maybe any leaking spills out of the evaporator drain, there is always a small puddle under the transmission area.
Not looking forward to investigating this one, stripping shoes e36 revealed this is a nightmare job even with the whole dash out of the car :/

 

[Clarkey]

Well I guess I'll eat my words now. I have done this without any kind of issue 4 or 5 times before though on identical cars, which leads me to believe there is something faulty on my car.

 

[Clarkey]

It finally broke down, had to abandon at 1am, it turned itself into a kettle. Could be curtains for the e36, a golden opportunity to go back to jap scrap maybe...

 

[Clarkey]

double you tee eff

what did it do to itself?

apparently it had no coolant in it, I went back to it this morning and it took 5 litres. Now it's back to it's normal business of running fine but having no heat below 1500. Bear in mind though, before I went out last night, the coolant warning came on and I put some in so it somehow lost an awful lot.

 

[Clarkey]

Found a leak. Actually more of a torrent, coming out under the car directly under the heater core. Presumably the leaking core is draining down the evaporator drain pipe (lowest point in the HVAC box) and coming out underneath hence not having damp carpets. The carpet directly under the core is damp actually, I took the console out to look.
I can't feel any wetness on the piped going through the bulkhead from the engine bay side so I guess it isn't simply leaking from there.

 

[Clarkey]

It's definitely the core yes, I unhooked the drain pipe and water was flooding out.

 

[Clarkey]

So how did you not notice the drive being completely soaked in sticky coolant or water?

It wasn't there before, leak has become considerably worse quite quickly though. The drain comes out on top of the gearbox so I guess when it was only a slow leak it all evaporated from the gearbox before reaching the ground.

tenwierdufos, you can see the drain pipe if you simply pull out the OBC and cubby hole. I assume you would certainly have the accompanying window misting though.

 

[Clarkey]

I will bear that in mind for next time. Managed to drive it home without any drama last night though, even with working heating at any rpm range. The one last thing I did before leaving was replace the radiator cap, I think that may have helped somehow.
The heater matrix is still having a good old leak though. Only explanation that I can think of is that the used one that we fitted (which was fine before) had become damaged. I've ordered a brand new one anyway, so will put that in and hope for the best.

 

[Clarkey]

Ugh, finally got this thing back in one piece. It was still leaking water out of the heater box with the replacement (used) matrix in. Despite the fact it didn't seem to be losing coolant level, I replaced it with a brand new one, then it sprung a massive leak from the hose connections.

It's working ok now though, only issue is that when idling the heat is quite a bit hotter from the passenger side than drivers. Both feed pipes into the matrix are scalding hot though so it's a bit strange to me. The only thing left is the heater valve unit, apparently they can become blocked so I'll get another one and clean it.

Two things I learned..

Changing heater matrix in an e36 is ****ing awkward.

Trying to bleed out the cooling system is a waste of your time.
My method...
Remove bleed screw and tank cap. Fill it up to the brim, keep adding more until no more bubbles come out of the bleed hole.
Bleed screw back in. Squeeze rad hoses repeatedly, you want to see a nice stream of water going into the expansion tank every time, with no air. If the level falls, add more.
Cap back on, drive the car for a good few miles, wait for it to fully cool down (I mean overnight) then repeat the procedure.
It will 'bleed' itself during normal driving, I found idling and/or revving just doesn't work.

If you have a leak then it will royally **** everything up and you will NEVER get it bled properly.