Sudden major loss of coolant while driving
 

Hi there

I've recently experienced some coolant leak in my 1995 850 - 183,000 on the odo.
I took it to the mechanic since I am not too experienced when it comes to fixing cars. He found a small leak and advised me to replace the expansion reservoir which I did. The car has never had any problems of this car before.

Since then I drove the car for approximately two weeks without any problems and I checked the coolant level every day. No leaking, the level stayed the same.
Then suddenly a few days ago the low coolant level warning light came on while I was driving. I stopped the car and popped the hood only to see that the coolant level was very low and seemed to be bubbling. The engine, however, did not overheat at any point, it stayed at the normal temperature. It's important to note, that I had just checked the coolant level earlier that morning, it was the same as the last two weeks, and I had only been driving for 15-20 minutes, when the light came on and the coolant was gone.

I've left the car parked ever since. The coolant tank is completely empty and I figure I'll bring it by a mechanic, but since I don't want to spend large sums on fixing, I wanted your opinion on what could be wrong beforehand.

There is no white goo when I check the oil, and I haven't noticed oil in the coolant (neither did the mechanic).

What could be wrong? (I'm really hoping no head gasket issues..)

Thanks in advance

The only sure way to know is to pressure test the coolant system.however you can check the hoses going to the radiator and the radiator itself. Take the timing belt cover off (single 12mm bolt) and check for any leaks at the water pump BUT I'm willing to bet your heater core is leaking. Pull the carpet on the driver side from the gas pedal towards the door, there you will see a black cover held together by a single torque screw. You can then check if the heater core is leaking, usually you will have a strong coolant smell coming from the vents and a wet carpet on the driver side depending on how much coolant leaked out.

Good idea to get a pressure test. you can also do a look around - check the sides of the radiator for cracked seams (will leave some residue) as well as the lower radiator hose connection points, hoses to/from the block and the thermostat housing for anything. Agree on the heater core as a good thing to check. If you get a slightly sweet smell from the vents when the car first starts up, that's a sign... 850s have a constant flow through the heater core so your heater settings doesn't matter (the climate control only activates the blender doors).

So I checked out the stuff you guys told me too, and it is definitely a leaking heater core. Underneath the carpet it's really soaking and smelling of coolant, and I can see the coolant trail from the heater core.

Everything else seems to be fine though, I haven't found any other cracks.

Now the question is what I should do about this. I have watched a couple of guides on how to change the heater core in an 850, and it seems pretty straightforward and way easier than in most cars. As I don't have the money to pay a mechanic to repair/replace at this time, I'm thinking I might go for it myself.
The second option is to bypass the heater core and live without heating/cooling in the car. Guess this will be less funny come winter, but it should be a quick fix though.

What are your suggestions, what would you recommend I do?

Well, looks like you and I will be spending the weekend the same way. Heater cores are cheap and can be replaced in under an hour. When I lived in Miami , most older cars were bypassed but if you live in a colder climate then I would just replace it. Heater cores can be had for as little as $50 on ipd.

Looks like it! I found the exact heater core I need for $35 on eBay, and it even comes with life time warranty. So I'm pretty sure I'll go down that road. I live in North Carolina so right now I can live without heat, but I'm not sure it'll be like that in a few months.

Run that heater core through your dishwasher before installing it. Yes, you read right...run it through the dishwasher.

There is a coating on it that stinks forever if you dont get it off.

Lol, really?


Personally, I would stay away from "no-brand" eBay parts and yes, I'm speaking from experience. Nothing wrong with shopping on eBay but buy a quality brand name and be done

Decided to get mine knocked out tonight. It was leaking where the plastic meets the radiator portion. Now how the heck am I going to clean these carpets...

There is an ebay brand that LOTS of people are using. I have installed 5 of them. Some are 5 years old, no issues.

Kris, I am currently running with the heater core bypassed, and I gotta tell you I could sure use a defroster! I have installed 2 of the ebay cores, and they do stink terribly. Going to try APDI/PRO brand off Rock Auto.


These heater cores are mercifully easy to replace.

So I installed my new heater core two days ago and it's working perfectly. The job took me around 1 hour and was not very difficult. So far no leaks at all and the coolant is staying at the same level every time I check it.

Thank you so much for your help and tips! :)