I'm new to this site. So, let me introduce myself. My name is Bill Capetanos and I own an 84 300D Turbo. I use this car as my daily driver. My other car is a 67 mustang race car. (at the moment, completly disasembled.) I've had this car for a couple of years now. I have done a few repairs. The glow plugs, radiator, and brakes. The problem that I am having is with the heater. At idle, and not moving the heater works fine. Once I get going, sometimes it works and sometimes it blows nothing but cold air. I have checked the vacum lines and found no cracks. What else could be the problem? I'm learning as I go here. I'm used to working on nothing but Fords. Any help would be much appreciated.

The temp stays right at 85. it justs rests at the top of the 8 in 80. I replaced the radiator last year and run 40% coolant and 60% water with one bottle of Redlines Diesel Waterwetter. Even climbing the grapevine on highway five at about 80mph, it didn't heat up past 95.

Hey Bill, don't be bashful send him to that great new site everyone is raving about!!!

http://mbdieseldiy.tripod.com/index.htm

I see that an 84 SD has a Monovalve so the D probably does also, no?

Billybob.

That site is great. I'm actually going out to garage right now and gonna have a look. You know, there are a lot of Bills on the board.

I went to that website. Then I went out to see my car. I found what I think is the monvalve but, it's called a heater control valve in my Haynes repair manual. Is this the same valve here?

Bill:
The Web site is unbelievable. If we take something apart, or change something out can we submit the information and pictures to help out the Site. I am a real hands on person (Failure Analysis Engineer) everything in this house that fails comes apart, and most of the time goes together repaired. I just sent a detailed description on how to take a fuel sending unit apart and clean it, I wish I would have taken pictures. If I can help let me know. How about the injection pump? I repaired mine, and did the research.

PeterG

Haynes? that's their problem, their editors don't know about this forum!!!!!LOL

I don't have a Haynes so I can't compare but its probably the same thing they just use non-MB speak!!

You can just follow the directions and check the piston diaphram in about 5 min., if its failed you can get the monovalve repair kit ordered from Fastlane and have it in a couple of days, another 10 minutes and your good as new. Good luck!

Billybob.

Thanks. My haynes repair manual has been my only source for about a year. I had to figure out most everything on my own. i didn't mind though. The pictures are good are a good guide too.

I'm ordering my repair kit from fast lane right now.

thanks

Billybob.

What's your opinion on my brake upgrade question?

Well, the mono valve repair kit is on its way from fastlane. Thanks for the help. I was about to take my dash apart on this one. That sure was an easy fix.

Brake upgrade question?

Repairing your monovalve will have a negligible effect on brake performance!!!!! LOL

Seriously I know absolutely nothing about MB brakes never having the opportunity to work on mine yet. Honestly I am one of the newer members of this forum and my actual experience is fairly limited to my 87 SDL and the couple of issues I've had and have with it. The first repair I did was the monovalve a couple of days after I found this forum. I saw the FAQ/DIY site as an opportunity to share the little I did know with others who could benefit from my limited experience. I am greatly indebted to all the individuals who share the incredible breadth and depth of wisdom and knowledge not only related to these fine automobiles but in many discussions on an enormous range of subjects.

I’m sure that someone with greater knowledge than I will eventually read your question and perhaps have the exact answer you need, until then Good luck!

My heater problem is that it gives out very little heat whether the car is at idle or highway speed.

Could it be the monovalve or something else?

Any suggestions will be greatly appreciated.





David


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1985 300D Turbo