PeachParts Mercedes-Benz Forum - View Single Post - Why does my heat only work while sitting still?

rcounts · #7 11-26-2008, 09:05 PM

Good news and bad news.

The bad - unplugging the power from the monovalve did nothing. The one on my car apparently needs power to OPEN, not to close. The rest of the bad news is that the diaphragm in it is totally shot - ripped all the way around where it attaches to the plunger.

The good news is that removing the "guts" worked! All I had to do is remove the e-clip from the end of the shaft and slide the plastic spacer ring, rubber stopper, and filter screen off the shaft and slide the soleniod and the rest of it back into the body of the monovalve. I left the outer portion of the diaphragm in place because it didn't look like it would seal up water-tight without it.

Took it for a test drive and VIOLA' I have all the heat I need! With the blower off it barely puts out just a tiny bit of warm air, but with the blower on high it warms the interior up real nice and real quick, and with the blower on low it still blows enough warm air to keep it nice and comfortable inside.

For anyone else in this situation, this is just a temporary fix, but one that will work quite well until you can get the parts to fix it permanently...