86’ E23 L7 - Coolant Vapor From Vents & Total Coolant Loss From Engine Bay

[Symboria]

First time poster!

I have an 86’ L7 (E23) that I have been working on for many months. I recently customized the fuel system and took it for a spin after all of my hard work. As I was cruising around town, I noticed a small amount of condensation on the windshield. After a couple of minutes, I could actively see vapor coming from the dashboard defroster vents. I immediately pulled over and turned the car off. I got out of the car to find that a massive amount of coolant had spilled all over the ground. There was NO indication that it had spilled prior to me pulling over. It appears that it only spilled once I was stationary. DISCLAIMER: My AC/Heater hasn’t worked since I purchased the car. The climate control buttons do not stay depressed when I press them and I haven’t bothered prioritizing why it doesn’t work so I don’t believe that this issue is related to the use of my heater. I towed the car home and removed the radiator hose network from the expansion tank/heater core/front-of-engine and did not discover any damaged hoses.

I’m at a loss and it’s frustrating to diagnose. My engine temp gauge doesn’t work so I’m afraid to drive the car until I can pinpoint where I’m losing coolant from.


I hope to help contribute what knowledge I have to the this community in the future!

[shogun]

moved to E23 sub forum

[Hit Man X]

Sounds like your heater core has failed.

[Symboria]

Is there a way to bypass it without removing the entire interior?

[Hit Man X]

Yes. Pass side is your heater valve...connect a heater hose to the inlet to that, run across valve cover, hook it to the other line.

It makes more sense looking at it.

[Symboria]

I'll look into that and come back for additional advice w/ pics. Thank you!

[rrbacon]

I had similar problem and it was the heater core. Replacing it was not easy but did get it done and so far no leaks