Glow Plug/Light Question '81 300D - Benzworld.org - Mercedes-Benz Discussion Forum

Joey · 10-09-2004, 12:34 PM

Since it's the weekend, I thought I'd post this and see if anyone has ideas...this way I can be proactive with my mechanic once the week begins.

Here's the situation:
I noticed a few weeks ago the glow plug light lit up while I was driving. It lasted about 7-15 seconds. Then, one day last week, the car was very difficult to start and the light stayed on for about 15 seconds...normally it goes out after about 3-5 seconds. I turned the key several times to preheat and just kept on it until it finally started. This morning, the same thing happened. So, I preheated about 10 times until the engine turned over. Also, each time I preheated, the light remained on longer than normal. Does this sound like the glow plugs just needing to be replaced? Thanks in advance!

DOUGLAS MARTIN · 10-09-2004, 12:48 PM

If the glow plug light flashes it usually means one glow plug is shot. If the light stays on you may have more than one plug down. The glow plugs don't cost much but replacement will try your patience a bit - easy access is not in the MB dictionary. Be sure to ream the pre-chambers before installing new glow plugs - failure to do so will hasten demise of new plugs

Joey · 10-09-2004, 01:32 PM

Thanks! I looked through the archives and kept coming up with plug relay issues, which I didn't think this was. Anyway, while I was driving, I believe the light flashed a bit, but then went out and never came back on while driving. The only time it has remained on for any length of time was upon starting last week and then again this morning. I will look into buying new plugs and will still probably take it in to have them replaced...I wouldn't trust my technical abilities to it.