I'm new to the Mercedes Diesel experience, and when I bought my 85 300DT a couple of months ago I really didn't know what I was getting into. I really enjoy working on the car, but I've had various levels of success at everything I've tried so far. So to that end I wanted to post about a somewhat interesting experience I had:
A friend of mine, who has more experience with these cars, commented that the car seemed to be running really cold in his experience. I could drive the car for 20+ minutes and the car wouldn't get above 80C on the temp guage. I thought the temp gauge was broken. Or, I pondered that his car might run hot. Well, I was trying to get free shipping from Autohauzaz.com (I was buying a monovalve repair kit for a different problem, obviously) and ended up buying a thermostat by reasoning that it would be about 10 bucks shipping, or buy the thing for 25 bucks and get free shipping. Anyway, I went to install it a couple of days ago and I have two things to say: 1st, wow that was easy. And second: my gas mileage has gotten about 50% better...I think the car was running so cold it never got to optimum running temperature. Just thought it was interesting, and other people might benefit from the experience.
Also, in reading about the common problems people have with monovalves, I was nervous in changing mine that I wouldn't know if it was faulty or not, I mean, how can you tell? There aren't many good pictures of faulty valves. So, if anyone else has that concern, don't bother stressing. It will be EXTREMEMLY obvious to you when you remove the old valve. Mine had completely worn through in 2 places. Incidentally, it still didn't correct my problem, which is another lesson in and of itself. I'm sure that I'm that much closer to figuring it out. BTW the monovalve is also extremely easy to change, however, be prepared to have some struggle removing the old valve from the case. And you'd be well advised to disengauge any coolant hoses ad remove the monovalve casing.
Anyway, peace out. Happy weekend...Thanks for the forum, info. and personalities...