'81 380 SLC.. Too much heat
 

My '81 380 SLC seems to have a problem with the heat. The heater blows too much heat, as if there is a valve that is stuck open or partially open. I have looked under the hood and found a cluster of heater hoses on the right-rear side of the engine compartment. There is a solenoid/valve that I assume controls the coolant flow. Is there anyway to troubleshoot this valve ? Thanks in advance for all your help.

Pay 5 bucks to George Murphy at Performance Analysis (george_murphy@compuserve.com) for his guide to troubleshooting this system.

You could need anything from a foam tube for the dash sensor to a new servo, which is the gizmo in the engine compartment.

Your problem could also very likely be the "mono valve" attached to the fire wall in the engine compartment. Performanceproducts4benz.com sells a
mono valve repair kit for $32.55...these can often get stuck and cause the heater to stay on. Easy to do yourself as it is a drop-in part and seal...good thing to replace anyway. Much cheaper to try this first before more expensive options...Good Luck!

JEFF & JO
84' 380SL (212K)
91' 300CE (131K)

Sorry, Jeff & Jo ...
 

... but the 1981 SL's don't have mono valves. They were the last of the vacuum-controlled servos.