1995- 850 wagon- non-turbo.
OK...the car smells like anti-freeze, but there is NO fluid under the mats...I think that it is weeping from the core and not enough to 'flood' (I think...I know nothing). I cannot find any leaks under the hood...
Put the heat on, even slightly, and you are blown away by the smell.
What else should I check?
Now, let's assume that I need a core. I will NOT be doing this myself...no time...getting too cold outside.
I have a small shop in town (no dealers around) that is an expert Mercedes shop...he is willing to do the job.
What info can I provide to help with a fool-proof job (ie: I don't want the dash to creak / squeek afterwards...are there any 'extra' parts that need replacing while doing this job? Things that only soomeone who has done this realizes should have been replaced)...
I will have him also do the A/C evaporator.

The heater core only needs to leak a little bit for you to be able to smell it inside the car. There is nothing else that will cause that smell from the air vents.

The dash doesn't need to be removed for just the heater core, so noises after the repair shouldn't exist.

There are o-rings for the heater core pipe fittings that should be replaced.

If this is done while replacing the evaporator, it is really a 5 minute job since you have the complete climate assembly out and the heater core disconnected.

There are several posts on both of these repairs, with excellent instructions, so maybe you could give that info to your shop.

http://www.matthewsvolvosite.com/chat/phpBB2/viewtopic.php?t=12317

B

Great writeup...NOW...if I don't need the A/C evaporator...what is the procedure for doing JUST the heater core? I have heard that it can be a one day job, but painful on the hands.

When I had a leak on my heater core a few years ago, first thing I have noticed is a slight fogging of the windshield.