Heater overheating
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Senior Member
Joined: Aug 2004
Posts: 285
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From: Richmond, Va.
1991 300E
Heater overheating
I have a 93 300E/E320 that I recently bought. The previous owner had just replaced the radiator. After driving for a couple of weeks I noticed that the coolant level always seemed low. After filling it up several times I started to notice leaks under the car. Then driving into work yesterday I started to hear the fluid behind the dash sound. This morning while driving in with the bi-level switch on the climate control, the car started blowing out only cold air no matter what I had the climate control set on. I then noticed that the car was overheating, almost to the 120C notch. I turned off the climate control, pulled over and refilled my coolant which wasn't all that low and drove the rest of the way in with the climate control off and everything was fine. The "low coolant" light never came on, and it was about 50 F outside. I thought it was odd to be running that hot and only about a 1/2 gallon low on coolant with the outside temp that cold. So my diaganosis is, I have either a broken heater line or a leak in the heater core. I haven't had a chance yet to get under the hood and look, but I assume that's where my coolant is leaking from because with the heater off the car doesn't seem to loose coolant. Any other thoughts? Also if anybody has the W124 service manual, I can't seem to find job 83-100, removing the heater housing. If somebody could email that PDF to me I would greatly appreciate it. Thanks, Matt.
Last edited by mhorn; Jan 18, 2006 at 10:12 AM.
