Strange Glow Plug Light Flashing....just wondering... - PeachParts Mercedes-Benz Forum

Jimmy Joe · #1 12-06-2004, 03:54 AM

(I spent an hour searching the threads, and read many references to it, but....)

Every time I start the beast, the glow plug indicator light flashes for about 30 seconds after it starts. It is solid of course, when warming the plugs, then flashes once started.
The threads I read all agree that that is an indication that there is a problem with the system. I have replaced all the glow plugs, checked the wires, cleaned the contacts at relays, and still it flashes.
It has always flashed, and there has never been any other indication of another problem. (with the glow system)
Should I just give up? I mean, if it works.......

kamil · #2 12-06-2004, 07:33 AM

This is what mine did:

I had brand new plugs put into the car about 6 months ago so they were virtually new (Bosch). It was a 50% chance that the light would come on when I preglowed so sometimes it went on and sometimes it did not. I changed all the plugs and the light comes on all the time. I know this is not the problem you are having but I'm just trying to show you that glow plugs can go really really fast. Instead of buying new ones though I took the ones from the donor car and they work great. Make sure you check your plugs, I was very hesitant in doing so since I just changed them. At first the light did not bother me either but now that it gets 30 degrees here it was giving me trouble starting. Not anymore....

Kamil

P.E.Haiges · #3 12-06-2004, 09:23 AM

JimmyJoe,

Do a resistance check on your GP. You will find the procedure by using the search function.

The flashing GP light is telling you that is is detecting a bad GP. I hope you kept the old GP so you have some spares. I never replace all the GP at once, that's like replacing all your light bulbs because one burned out.

P E H

boneheaddoctor · #4 12-06-2004, 10:18 AM

Hmmmmm, my light never flashes......but it only comes on once in a great while, and only for about 5 seconds.......

But recently have hard start issues (only on a cold motor) related to a power loss problem......Maybe that was coincidentaly timed to my other problem.

Maybe I will order 5 new ones..............replace them all, and keep the good ones that come out for future replacements.

P.E.Haiges · #5 12-06-2004, 11:20 AM

Bonehead,

What do you mean by a power loss problem? Battery dead?

I would order 3 new GP, replace the one or 2 bad ones and keep the new one or ones for spares. You know, don't fix it if it ain't broken.

P E H

boneheaddoctor · #6 12-06-2004, 02:34 PM

Quote:

Originally Posted by P.E.Haiges

Bonehead,

What do you mean by a power loss problem? Battery dead?

I would order 3 new GP, replace the one or 2 bad ones and keep the new one or ones for spares. You know, don't fix it if it ain't broken.

P E H

No, loss off power not electrical problems. THis is my thread and ongoing story,

http://www.peachparts.com/shopforum/showthread.php?p=761819#post761819

I ordered 5 new ones....will keep good old ones for future spares. And trash the bad ones.

Jimmy Joe · #7 12-06-2004, 03:25 PM

Quote:

Originally Posted by P.E.Haiges

JimmyJoe,
The flashing GP light is telling you that is is detecting a bad GP.... I never replace all the GP at once, that's like replacing all your light bulbs because one burned out.

P E H

This points out another of my rookie assumptions doesn't work.
I figured if they were all new....
but then again when I was a gasser I would sometimes get bad plugs right out of the box.
Thanks for all your help, folks, just an outstanding community here.

dieseldiehard · #8 12-06-2004, 03:53 PM

There is one more item, at least in my experience, that causes intermittent flashing GP lamps, at least with the turbodiesels that use the GP timer that is a black module mounted on the L fenderwell. It is the temp sensor mounted on the head, if it gets flaky it causes this same thing. The lack of a solid signal from it will cause the timer in the GO relay to come on and off.
BTDT, I thought it would be the GP module so I swapped in another module (not a new thanfully I kept one from a wrecked car just for testing purposes) - still flaky. Replaced the sensor, all fixed.

boneheaddoctor · #9 12-06-2004, 04:17 PM

Quote:

Originally Posted by dieseldiehard

There is one more item, at least in my experience, that causes intermittent flashing GP lamps, at least with the turbodiesels that use the GP timer that is a black module mounted on the L fenderwell. It is the temp sensor mounted on the head, if it gets flaky it causes this same thing. The lack of a solid signal from it will cause the timer in the GO relay to come on and off.
BTDT, I thought it would be the GP module so I swapped in another module (not a new thanfully I kept one from a wrecked car just for testing purposes) - still flaky. Replaced the sensor, all fixed.

Now there is one aspect I never considered......................