3 Glow plug faults, bad harness?

[No Exit]

Sooo... I finally got the car back together and it actually started and ran around the block WOOHOO!!!

Thats the good news... now the bad news... I was so excited about getting the car out of the garage that I ran over my plastic timing belt cover.

While the car was running I got 2 lights... the engine light and the blinky glow plug light. The vag-com was hooked up so i searched for faults. Only thing that came up was:

3 Faults Found:
17055 - Cylinder 1 Glow Plug Circuit (Q10): Electrical Fault
P0671 - 35-10 - - - Intermittent
17057 - Cylinder 3 Glow Plug Circuit (Q12): Electrical Fault
P0673 - 35-10 - - - Intermittent
17058 - Cylinder 4 Glow Plug Circuit (Q13): Electrical Fault
P0674 - 35-10 - - - Intermittent

So am I to think I have 3 bad glow plugs? a bad harness? bad relay somewhere? I didnt have this problem 4 months ago when the car was running. The harness is the same but the glow plugs that are in there came with the used head I bought. The head was low mileage but had some nastiness on it (probably from sitting out).

I've got a couple of sets of plugs so I could change those out but seeing as how its 3 and its an "intermittent" problem, my guess is that its something else. Was I supposed to put that dialectric grease in there?

Any ideas?

 

[Mike_04GolfTDI]

It is not unusual for these cars to blow glowplugs. I bought my car new in 2004 and it has killed about 7 glowplugs (replaced under warranty). Other people have also had repeated glowplug failures.

It might be a bad harness. You should check the resistance of the plugs. They should be around 1 Ohm. If they are significantly higher than that, or infinite resistance then they are bad. This way you can tell if the plug has really failed or if it's just your harness.

 

[Tickbait]

Oddly enough when I was talking with the SA at my dealer, he told me a blinky glow plug light can sometimes be the result of a burned out tail light bulb? Never had this happen -or- have I heard of it before, but maybe there is something to it?

 

[ymz]

a blinky glow plug light can sometimes be the result of a burned out tail light bulb

Yup... a classic symptom of burned out light bulbs or a questionable brake light switch... I wonder how they thought that one up...

Yuri.

 

[Wingnut]

Yup... a classic symptom of burned out light bulbs or a questionable brake light switch... I wonder how they thought that one up...

Yuri.

Go figure...a flashing GP light has nothing to do with the glow plug system.

Actually, gass cars have an EPC light. This light comes on when there is an electrical problem of some kind, like a bad brake switch. Since the diesel clusters do not have an EPC light, they use flashing GP light to itell us the same thing...a fault in the electrical system somewhere, but not necessarily ENGINE related. Thus no CEL for brake light problems

As far as answering the original post, have you checked the plugs with a multi meter? If they are the original plugs out of the used head, they may be no good. You could also have considerable amounts of corrosion in the harness from the long peroid of inactivity. It doesn't take much for oxidation to build up. Try a can of Deoxit in the harness & check the resistance of the plugs.

 

[No Exit]

Thanks, I've got a multimeter but dont know how to use it . Probably easier to go at it with the shotgun approach and just start replacing things. If those glow plugs are gonna eventually go anyways, no harm in just replacing them now.

If that doesnt work I guess it'll be the harness next.

I think there was actually corrosion on the ends of the glow plugs when I put it all back together. Didnt even think anything of it. Just scraped some of it off and plugged them in. Thinking about it now, if that was the problem, there's probably a bunch of crud inside the harness now too. DOH.

Oh... and after driving around for a bit, the glow plug and CEL turn off. I assume its cuz everything is warmed up and there's no longer any need for the glow plugs if I should need to restart the engine. If it was a brake light problem, the blinky light would continue correct?

 

[No Exit]

Update... 3 bad glow plugs. Simple as that. Tested them after I pulled them out and they were indeed shot.

Guess the lights arent always as cryptic as they seem. Glow plug light actually meant bad glow plugs this time

 

[No Exit]

Update... 3 bad glow plugs. Simple as that. Tested them after I pulled them out and they were indeed shot.

Guess the lights arent always as cryptic as they seem. Glow plug light actually meant bad glow plugs this time