Audi A4 B7 - Broken glow plug. Is it anyone's fault - Audi666
Audi A4 sline 2007 170 bhp

Hi there, I was just wondering if anyone can offer me some advise. Last week I took my Audi into the garage because of an engine management light and loss of power.

They had it for most of the day and replaced the EGR valve but then removed it again as it hadn't fixed the issue. Said that I would need to bring it back for a full day for more diagnostics. So I booked it back in for the first available day which was the following week. I was charged £54 for diagnostics despite the fact that they still had not diagnosed the fault.

When I took it back in they said they would keep me posted and I left it with them. Around about 4.00 I called them for an update and they said they would call me back. At about 4.30 I still hadn't heard anything so I called again and they they said it was all sorted.

When I got there I got a nice bill for £544.96.
They had replaced the ERG value and the throttle body. Plus 2 hours labour. At this point I was happy that the car was sorted. They did mention that the wheel was pulling to one side which reminded me they I had wanted to get the valve replaced on the back alloy as it had a slow leak. They kindly offered to do this for free if I brought it back the next day.

The next day I did about 40miles and the car seemed to have the power back although it seemed to wobble a bit when idle.

When I went back for the new valve they discovered the tyre was damaged and said it would need a new one so I the had to go home on my space saver! While they ordered a new one. £75 ish

The next day I headed straight back to the garage to get my wheel back. Half was into my 10 mile journey back the front of the car just started shaking out of nowhere! Slowed down and eventually stalled. Had to push the damn think across oncoming traffic into a lay-by ??.

I called the garage who said they could even come to me so I had to pay another £40 for my own recovery to them! When I get there they opened it up and said that a glow plug had snapped off into the engine and it is likely to need a new one! (Engine) ??.

Now I don't like confrontation and I want to get to opinion of experienced mechanics like yourselves before I say anything here, but is this just coincidence should they be taking some responsibility for this latest disaster?

I really am keen to hear your views on this. Many thanks in advance for any replies.


Edited by Greg Caulfield on 24/07/2016 at 10:44

Audi A4 B7 - Broken glow plug. Is it anyone's fault - Peter.N.
Firstly I think it unlikely that a broken glow plug is anything to do with the problems you have had unless its so badly broken that its letting combustion gasses out and I'm sure you would have noticed if it was.

Glow plugs on common rail engines only operate very briefly when you first turn the ignition on and most engines will start perfectly well without them, they do run for a little while after the engine has started but this is only an exhaust emissions function it doesn't affect the running of the engine.

Broken glow plugs are not unknown on modern engines but the reason they break is that they seize into the head and the amount of force required to remove them breaks them, did they have any reason to remove the

Al the common rail engines I have experience of will function without the glow plugs working, I would ask your garage why they think a broken glow plug will affect the running of the engine.
Audi A4 B7 - Broken glow plug. Is it anyone's fault - elekie&a/c doctor
Agreed as above,your egr and throttle body have no relation with the glow plugs.The only issue you may have is if the glow plug has broken and has been ingested into the engine.This could be a major job.
Audi A4 B7 - Broken glow plug. Is it anyone's fault - Railroad.
Glow plugs are made of stainless steel and usually M10x1. The cylinder head is aluminium alloy. The threads pick up and seize on the way out. It would be a help on subsequent removal if the manufacturer used a high temperature anti-seize paste when installing them, but unfortunately they don't. Whether you could successfully bring a case against the manufacturer though is highly doubtful. There is a lesson to be learned though. Always coat the threads of new glow plugs when installing them. They'll be much easier to remove next time.
Audi A4 B7 - Broken glow plug. Is it anyone's fault - hardway
Throwing in my 10c...
No tech I know would ever go anywhere near glow plugs unless they really REALLY need replacing.
The are an absolute pain.
shearing off flush with the head.
You state "they opened it up",
Does that mean the took the head off?
Audi A4 B7 - Broken glow plug. Is it anyone's fault - Audi666
Hi thanks for your reply. Yes they took the head off the engine after I had to be towed back in. Whether they did that before I wouldn't know.
Audi A4 B7 - Broken glow plug. Is it anyone's fault - Audi666
Hi Peter, thanks for your insight. The garage said that the glow plug had snapped and fallen into the engine and will have caused serious damage to the Pistons in the 3rd cylinder! They are not blaming the glow plug for the original fault as the car was actually drivable before it entered their garage. They said that it must have fallen of on my journey back to them just 2 days after they "fixed" it. Basically moments before the engine just destroyed itself from the inside!

I find it hard to believe that such a rare and unlucky event would just happen 2 days after they have had it. Could it be that they have over tightened one puting it back on? I can actually recall getting a few glow plug warning lights in the run upto taking the car in. I assume that this would show up on the diagnostic and would have been looked at? Especially if they spent 2 days on it.?

My main question to each of you if what would you guys do in my shoes? Would you dispute it? Or just take it on the chin?

Thanks again
Audi A4 B7 - Broken glow plug. Is it anyone's fault - chris.o

Is it possible that during those " I can actually recall getting a few glow plug warning lights in the run upto taking the car in" miles the glow plugs were actually coming on? I have seen glow plug tip failure on a diesel engine where the glow plugs were coming on during a journey because of a faulty controller. Basically they were glowing for long periods whilst running leading to the tip of the glow plug falling off. (It wasn't a VAG group car). You could ask for some photos of the failed glow plug?

Audi A4 B7 - Broken glow plug. Is it anyone's fault - Audi666
Thanks Chris

My understanding is that a burned out glow plug will fragment/disintegrate and cause less if any damage. Mine however seems to have broken off in one great chunk. I haven't seen the plug that fell off. Once the shortened end left behind. It looked like a clean break. I will try to get photos.
Thanks again
Audi A4 B7 - Broken glow plug. Is it anyone's fault - elekie&a/c doctor
I think you have to ask the question,did it break of its own accord or was it pushed.?Has there been previous human intervention that has cased this problem.Did the garage remove the glow plugs for any good reason.?