After having read a bit about leaking heater cores here and realizing it was a hot topic, I checked my driver and passenger footwells in my 93 945 for moisture. Low and behold, I found the area under the mat on the front passengers side to be a bit wet with moisture on the underside of the mat. Now I can't rule out the fact that one of my kids or my wife spilled water, diet Coke or some such thing there and forgot to tell me.

I have added a about 6 ounces of anti-freeze over 2 months, if that to the coolant tank.


My questions are:
1.Where is the heater core on a 93 945? The hoses appear to go through the firewall on the drivers side.

2. Where does the coolant/water typically pool when the core leaks?

3.How slow or fast are these leaks?

4.I don't notice fogging of the windshield when the heaters on, but here in the SE PA area, the heater has not really been on!


Thanks!

Hi John,

Heater core is attached to the firewall, under the dash, up and behind fuses sightly to the left of centre.

My coolant pooled in the left front passenger footwell. If your coolant is mixed to 50:50 ratio you will most likely smell it and see an orange or green liquid beneath your carpet.

Leak depends on degree of corrosion or damage.

With your car being a 93 it is imperative you change the heater valve if you haven't already done so. An easy, inexpensive job.

Take care,
John H from Downunder

Hey John H.,
Where and how do I replace the heater control valve? Have you done it?
Don't think I read about it in the FAQ.

Thanks, John
--
John 93 940 Wagon 66K

Hi John,

It sits in the middle of one of your heater hoses and can be tucked away out of sight. From the left hand side look and feel below the distributor cap at the rear of the engine. What you are looking for are 2 cylinders attached to each other. One of them is made of metal about 1" diameter by 1.5" deep. The other, which the hose attaches to is metal/black plastic.

There should be enough slack in the heater hose to gently pull it out so that you can remove the small vacuum hose and use a screwdriver or small socket to undo the 2 circular clamps. Before you remove it from the hose, check the direction of the arrow on the plastic. If I remember rightly it needs to point toward the firewall.

I replaced mine while there was no coolant in the system. If you are quick you should not lose too much coolant.

Purchased mine from FCP Groton for around $15US, they had the best online price and support Brickboard. The brand I received was Scantech. Would have preferred it to be totally metal, it seems however nobody makes them.

As Steve explains the job is easily done. With only 66k on your car you most likely are not yet in the danger zone.

Take care,
John H from Downunder

It's in the FAQ under "cooling system" as well as "heating air conditioning". The valve is mounted in the heater hose, right behind and a little below the intake manifold. Two clamps and a vacuum line.

I am currently replacing the heater core in my '89 765. (I have the dash out, and I'm about to crack open the ECC unit itself.) I didn't really notice the loss of coolant. What got my attention was the smell of coolant in the cabin, the total and complete lack of defrost ability (the windows would just fog more), and the telltale green drops on the floor vents to the right of the driver and the left of the passenger. For your sake I really hope it's a loose hose in the engine compartment that is leaking into the cabin, or there is another place where you are losing coolant.

Good luck,

Eric

Heater core is located on the drivers side, roughly above and to the right of the gas pedal. Coolant usually pools under the carpet on the drivers side. Can leak a drop a week or a quart a day, depending on amount of damage/corrosion. Leakage will be apparent as coolant stains the heater box when it leaks. Remove the under dash panels and have a look at the heater box for green coolant residue.

For the life of me, I don't understand why they don't just design a side hatch in the passenger well... which allowed ready access to the heater core and the hoses. One could simply pop open a side door to the heater matrix... disconnect the hoses and slide out the heater core in 20 minutes.

Instead of having to dissect half the interior dash, steering column, center panel, glove box, electric panel and vacuum lines first to get to it!!!

Ugh!