Hi, I ran out of diesel and since then my 300td has... - PeachParts Mercedes-Benz Forum

Matt Petty · #1 07-06-2003, 01:41 AM

run quite a bit hotter, according to the gauge.

I'm new to this board and am very impressed with the weatlth of previous posts. I've searched the forum for my particular problems and have formulated a few theories.

Here is what happened: I ran out of diesel in my 1979 300td about 2 gallons prematurely. I ran the car about a mile with it sputtering and trying to die at low rpms. Fill-up and the wagon runs fine after a couple of seconds. Since about a day later my temp gauge, on the freeway, has read from 175f to just under 200f. Before this change in temp I was rock solid at 175f regardless of load, even really tromping on it. Now the temp. fluctuates much more depending upon load. It also seems to heat up a bit faster. I haven't owned the car for very long but I would swear that the hot idle is a bit shakier also. I realize that mt new temp. is acceptable, but it has changed quickly and I do not trust the car anymore in extreme temps.

So far I have spun on a new fuel filter, new thermostat and coolant (old was rustynasty).

To begin to troubleshoot this problem I am first going to do a comp. check and valve adjustment just to start removing variables and to learn the procedure. I'll change the second underhood fuel filter as well as the tank screen. Probably flush out the tank.

My questions are:

1) Could grit from the tank have caused this by blockage of one of the three fuel filters resulting in constant mild fuel starvation?

2) Could grit have made it past the filters and into the IP or lift pump or injectors and caused the jump in temperature? Remember that I ran it for a bit while it was sputtering.

3) Could air be in the system? I am unclear on bleeding procedures and can see small bubbles in the second transparent fuel filter.

4) Whatelse could it be?

Everybody seems to like a challenge in this forum. Please ask any questions which may help troubleshooting. Hopefully I will have my skills down to the point of helping someone else out soon.