I'm not getting much heat in our '91 300SE. I have changed the Mono-valve insert. Still not much heat. In review of threads, it sounds like the next part to check is the aux pump. Where would I find this critter??
Thanks for the help.
Steve

As it is mounted at the bottom of the mono heat valve, its somewhat a pain to get to. It's basic function is to supply hot water at idle, so that at stop lights you don't get cold air coming out. If you aren't getting heat w/driving tham aux water pump isn't the problem. Possibly the thermostat isn't allowing engine to reach correct temps.

Thanks for the info, I'll change it and see if that gets it. Should be a lot better than the $'s for the pump.
Steve