Are my glow plugs dead? - PeachParts Mercedes-Benz Forum

Veloce300DT · #1 01-30-2004, 09:28 PM

For the past couple of days my car has failed to start in the morning after cooling off all nite. I turn the key and let the coil light go out and nothing happens. To get it started now I have to repeat the starting process 5= times and then wait about 10 minutes, come back, and then it usually starts right up as if there is no problem. It doenst hesitate to start throughout the day once its been driven.
Everything on the car runs fine. In fact ive spent at least 5K over the past 4 months bringing everything on the car up to date-new front end etc etc etc. The funny thing is is that with all 3 of the diesels ive owned, ive never had to touch the glowplugs. So im new to the problem of them burning out. Im thinking thats why im having starting trouble. Any suggestions?

WANT '71 280SEL · #2 01-30-2004, 10:11 PM

glow plugs would be a cheap insurance policy. Does the light blink for about 45 seconds after the car is started? How long since the last valve adjustment? I bet that's where your problem lies. If not there, how about IP timing? Does the car smoke heavily when it is at running temp or cruising down the road?
Thanks
David

Stevo · #3 01-30-2004, 10:21 PM

"never had to touch the glowplugs. "

Wow... you've owned allot of Diesel MBs and never had a glow plug problem, you must have lived in the tropics. Move over, I,m on the way

Do a search with "GPs", there is lots of good info in the archives. You probably are gona need a set of GPs but you can find the ways to test them. Do you have a manual, Haynes covers most basic things fairly well, and the manual in CD form can be had from eBay.

Veloce300DT · #4 01-31-2004, 02:39 PM

David-
Valve adjustment was last performed at 151K miles in september. Car just turned over 159K miles this past thursday. The coil light doesnt blink after the car has started, but it seems to stay on for a shorter period of time during the first few starting cycles.. seems to stay on longer once the gps have warmed up more?
Car doesnt smoke much at all, very little when at running temp, and even less once on the road. Its never really smoked much at all, its the cleanest running 300D ive owned.

Stevo-
HAHA yeah, its pretty rediculous that in all the 3 cars ive owned with a total of 85K miles so far covered in all 3 combined over the past 3 and a half years, that I havent had to deal with any sort of glow plug problem until now. As far as weather goes, its not quite tropical, but close for the US id say. I mean, its very mild compared to the rest of the country. Daily highs fluctaute from 55 in the winter to 110degrees in the summer depending where you are. Bay area highs are lower than valley highs in the summer, and warmenr in the winter. I own a Haynes manual, havent gotten around to getting the cd manual yet.

psfred · #5 01-31-2004, 03:01 PM

New glow plugs. #1 is going bad, that's why the light goes out fast (I'd guess the filament is shorted0>

You won't strain your GP much in that climate -- what really makes them die is a long burn from -20F every morning!

Peter

JHZR2 · #6 01-31-2004, 10:26 PM

I have a similar problem... valves adjusted, strong runing engine with great economy and no smoke. Just doesnt liek to start when it gets too cold, unless I glow and crank a number of times.

I decided to change the fuel filters and ran some diesel purge through straight.

The car is always driven on the highway, so I dont see why there would be carbon buildup, but now it starts almost as if it was 90F out after one glow when sitting for days in 20F weather...

Id consider doing a diesel purge, especially if you drive around town a lot and the engine doesnt get worked too hard. You might have carboned uo glowplugs.

JMH

Veloce300DT · #7 02-02-2004, 04:50 PM

HMMM things have changed... now the glow plug light lights up for an even shorter period of time, but instead of having to cycle through the starting process numerous times to get the engine to turn over, its started up just fine with no hesitation.
As for running diesel purge through the system, i havent tried that. I doubt that that will solve the problem that Im having but who knows.
The car had been sitting for 2 months in my garage while I was on some trips, but I had someone start it up once a week to let it idle for a good while to keep things from becoming stagnant. When I got it back on the road I ran some Red Line fuel catalyst in the tank and repeated that again on the second full fill up. I drive mostly city driving since moving to San Francisco, but there are plenty of hills that really give the engine a good run. Im not looking forwards to the extra maintenance and more current oil changes i'll be facing from driiving in the city, but youve gotta do what you gotta do.

dieseldiehard · #8 02-02-2004, 05:00 PM

Veloce300DT, stop by San Mateo sometime and I'll gladly check your glow plugs with an Ohmmeter, it takes but 15 seconds.
You will definitely use-up brake pads in "The City" - drop down a gear into 2nd on downhill inclines to allow the engine to act as a dynamic brake.
RE: GP life. Older MB's with loop style glow plugs lasted a lot longer than the pin style, the newer ones seem to have a more limited life. And yes the weather here allows quick starts so the GP's don't get a work out like they do in colder climates, another reason they generally last 4 to 5 years here in my experience. FWIW, I believe that diesel purge is a waste of $$.
DDH