300sd

Nov 15, 2004 12 Replies

now that i have it starting am having trouble getting heat to the cabin



thermostat is fine gage reads 80C



air has always blown out of the dash so i close it off with the slides in the winter.



the door is open by the foot peddles it will blow warm air but not hot till i turn the car off. once restarted it blows hot then cools a bit once you get it up to speed.



is there a damper door that mixes the out side air with heated air & if so where is it hiding? i don't want to pull the console off as it's an 82 and god knows what will break. the auto speeds work & the AC in the summer is fine as the mono valve closes the flow of coolant when the dial is turned down to the blue section



and the rear dome lite cover . does it just pop off



thank you



case



Sounds like your auxilary pump is not doing the job... Is the heater hoses hot? If it is just warm, then the aux pump is bad.

there hot but will check any way. it seems like after a min or 2 the air cools

also on the hottest setting with the fan on low it stays hot.

makes me think its mixing cool air with the hot.

any repair books i can get?

will buy one

the case, minus a few cans!

No... it definitely sound like aux. pump is not supplying enough hot coolant.

ere is the aux pump hiding? it has a hose from the waer pump to the fire wall?

the case, minus a few cans!

there is no aux ump on my 82 300sd the heater hose goes to the air cleaner and connects to a section of pipe then back to the hose. it then leads to the fire wall.

the case, minus a few cans!

Strange... I even looked up your 82... I was looking at 83 but still... same thing, they said you have it... but you don't.. I'll look up the service manual and see...

will sneak a peak Larry Thanx not sure where or what position it is sulose to be in but will find out.

AC season is over so i can stap it or what ever

case

the case, minus a few cans!

After I bought this car, several years ago, I had problems with the AC. What I found was enough to piss off the pope. The local "Foreign Car Experts" had fixed a broken control valve by wraping a rubber band around the flap arm. When the rubber band broke, .... well you know the rest of the story.

Larry In the back yard, under the oak.

air mix door was binding it is HOT now.

will see in January if it stays that way

the case, minus a few cans!

My understanding was this pump is only to help cool the vehicle during hot soaks (ie the car is shut off)?

Some people seem to eliminate or bypass this aux. pump...

Don't know for sure, but hoping T.G. or someone with more knowledge(then me) can explain this.

Marty

The aux heater pump is there to circulate cooling water through the heater core when the car first starts up. The idea is to get heat to the cabin faster. From what I've seen on my 300SD, it only seems to make a noticeable difference if it's real cold, the car is started and instead of driving off, you wind up either idling or moving slowly. Otherwise, as the engine speed increases to normal driving speed, the aux pump really isn't needed and it shut off after the coolant reaches a high enough temp.

well i never got one or it was removed any way that was not the problem. got heat now!

the case, minus a few cans!

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