coolant leak - PeachParts Mercedes-Benz Forum

j mindler · #1 12-27-2002, 05:52 PM

Hello all, I have a 1989 190e 2.6, and I have a coolant leak under the car when the heater has been on. I suspect a leaking heater core. Will the leaking coolant drain through the evaporator drain hose on to the ground? No leaks inside the car.

Thanks in advance, John

engatwork · #2 12-27-2002, 07:15 PM

Yes, if you have a leaking heater core it should drain through the same hole as the a/c system drain.

j mindler · #3 12-27-2002, 07:19 PM

Thanks for the reply, I'll start removing the dash next week.

haasman · #4 12-28-2002, 03:37 AM

J - I have been postponing doing the '87 190 heater core. Keep us posted on how it goes.

Haasman

j mindler · #5 12-30-2002, 05:23 PM

What I'll try to do is when I start the heater core replacement, I'll post some pictures of the procedure.

NDP 2.6 190E · #6 03-12-2003, 01:39 PM

Had a coolant leak that was creating a puddle (the size of a saucer) underneath the transmission.

After replacing the heater feed and return hoses and checking the heater control valve, I realized that the likely culprit was the heater matrix (groan!). Interestingly, there was no internal leak or odor in the car - even when blowing hot air!

Using the workshop manual, I proceeded with all the tasks that are required to remove the dashboard.

Not a particularly difficult job - but you DO need the shop manual to avoid additional frustration. I also recommend labelling ALL fastners (with masking tape and pen) and placing in containers grouped by sub-assembly to avoid confusion with re-assembly.
Label the climate control vacuum hoses too!

My heater matrix was leaking at the end-joint.
Whilst doing this job I also replaced: -

- the radiator (diagnosed as partially blocked by a local shop)
- serpentine belt (might as well, whilst radiator out)
- badly corroded transmission cooler pipe - attached to lower radiator

... a bit ambitous maybe, but hopefully worthwhile.
The radiator had been causing 'hot running' in traffic and was the likely cause of some recent hose blow-outs.

End result, no more leaks, cooler running and the heater works a treat!

Neil.