Glow plug issue

**carcav** · 25-06-2019,12:04 PM

Hi, I have a problem with the glow plug system. I have no warning light when key turned but relay clicks. Checked out relay and found it OK, no fault codes on VCDS. Did a instrument check and the light works. Would like a reply from Crasher (he's savvy on these things), Thanks for reading.

**Crasher** · 25-06-2019,01:12 PM

I can’t check the wiring diagram as I am off this week. Have you checked for battery voltage at a plug cap when you do an output test?

**carcav** · 25-06-2019,01:53 PM

Thanks Crasher for your swift reply, haven't had the cam covers off yet, its the 2.5 tdi AFB. Trying to obtain 6 rubber injector seals, to get them from Audi you have to buy the cam covers which is crazy.
When I get the seals I'm going to fit new plugs that I bought 15 years ago. Thanks again for your reply.

**Crasher** · 25-06-2019,11:15 PM

The glow plugs are external!

**carcav** · 28-06-2019,12:14 PM

The glow plugs are under the cam covers, it's a v6 AFB engine.

**carcav** · 28-06-2019,03:02 PM

Sorry Crasher, what a ****** I am. Found them. I've only had the car for 16 years, I always thought they were under the covers. Looks a nice easy job ( not). Bought cam cover gaskets so might as well
fit them. Thanks again.

**Crasher** · 29-06-2019,04:59 PM

As they come out they will make some terrible noises, I do them with the engine hot and spray Buy Rust remover Rost Off Black (0890200500) online and then ease them out and back in again and some more lube and then out again, trying to work the lube down the thread without damaging it. I get about one snap every couple of jobs but on one we did a few years back, all six snapped!

**carcav** · 29-06-2019,08:47 PM

Hi, when I pulled the wiring off the glow plugs I checked for power, found I had no power at all. The relay cuts in and out ok, the 2 big fuses are ok. Do you think it could be the ecu.
Would like to hear your comments. Thanks again Crasher.

**Crasher** · 30-06-2019,12:18 PM

The ECU commands the relay so if the relay operates the ECU is doing its job. The relay is in the plenum chamber box so it is probably water damaged internally.

**carcav** · 30-06-2019,02:33 PM

Hi, so the relay in the plenum box is the glow plug relay, is the one under the driver's side dash just the timer relay. It's bone dry in the plenum box, I tested the relay on the bench
and it's ok, but when I tested the power supply to it I found a dead short on the ground terminal. So I'm thinking the ecu is faulty, I can't understand why I'm not getting a fault code
with vcds. I've looked on the net but can't find a wiring diagram, cleaned workshop out and accidently throw my workshop manual disc. Thanks again for your interest.