Car Broke Down Last Night, Please Help - PeachParts Mercedes-Benz Forum

Uncle Possum · #1 04-13-2009, 01:27 PM

Last night about 90 miles South of Las Vegas, my 1989 300E suddenly stopped running. I was going about 75 mph and it was if someone turned the ignition off, no sounds, nothing. I coasted over to the side, called MB roadside assistance (works great btw). Checked under the hood couldn't see anything immediately out of place, oil good etc. Did notice that the exhaust was glowing red. Never looked at it hot and in the dark before so not sure if this is normal. After sitting and cooling for about 45 minutes, I tried starting, car turns over fine, but would not start. Tried again this morning before work, again will not start.

I had been having relatively long starts since I had the car (6 months), and gotten used to them. I have replaced plugs (non-resistor), plug wires that seemed to help some. Seems to start up quicker when cold, but not always. Also had slightly rough idle, which again seemed to get better with the new plug wires, but has since gotten to be about the same. Also, I had used the cruise on a previous trip and it worked great. Before the failure the cruise would disengage intermittently, eventually getting to the point that it would not work at all. Finally, the failure happened within 1/2 hour of topping off my gas tank.

Any help troubleshooting would be greatly appreciated.

TX76513 · #2 04-13-2009, 02:02 PM

Just ideas - Have you looked at distributer cap or checked the fuel pump relay?

ps2cho · #3 04-13-2009, 02:28 PM

The exhaust should not be glowing red.

Are you talking exhaust or the precats? If its the precats then they are done for. Most likely due to oil consumption. It's possible you might have a serious blockage. If you can, try disconnecting the pipe right after the manifold and see if she starts up.

MBeige · #4 04-13-2009, 03:21 PM

Don't forget the fuel pump...

Uncle Possum · #5 04-13-2009, 03:30 PM

Quote:

Originally Posted by ps2cho

The exhaust should not be glowing red.

Are you talking exhaust or the precats? If its the precats then they are done for. Most likely due to oil consumption. It's possible you might have a serious blockage. If you can, try disconnecting the pipe right after the manifold and see if she starts up.

The pipe that was glowing red was the single pipe after the exhaust manifold. Car does use about a quart of oil every 1000 miles.

I will see if there is anyway to disconnect and give it a try.

Thanks,

Uncle Possum · #6 04-13-2009, 03:32 PM

Quote:

Originally Posted by TX76513

Just ideas - Have you looked at distributer cap or checked the fuel pump relay?

Where is the fuel pump relay located, and is there any way to check it other than replacing it?

Thanks,

ps2cho · #7 04-13-2009, 06:23 PM

If you are using about a quart every 1000 miles that will eventually kill the precats + cat.
fuel pump relay sits behind the battery next to the OVP. There are two relays back there. One is for the A/C, the other is the fuel pump. I believe you can bridge the connections to kick it on without the relay seated....do a search on it.

tinypanzer · #8 04-13-2009, 10:00 PM

Yeah, but if your exhaust is getting that hot, then you had better worry about that long before you worry about fuel delivery. That could start a fire!!

I agree that your cats are probably toast, and you have a serious exhaust blockage.

Don't ignore that problem, it will only get worse, and by worse I mean your local fire chief will have a story to tell at the dinner table. Every once in a while somebody down here in FL will park a car like that on high, dry grass and 10 minutes later there's no car left.

Uncle Possum · #9 04-15-2009, 12:52 AM

Had it towed to the shop and found the ignition control module had failed. Replaced with used one. Still concerned about precat heating up, will check the first time I run it.

Thanks for everyone's help.