Glow plug broken

[SteveGoodz]

I've been having problems starting my 300Tdi on really cold mornings, so bought a set of glow plugs and went to fit them this afternoon. So far .. so good. Now the fun begins  :(

Firstly, getting to the front one required me to remove the air con compressor ~ and that didn't want to move until I got really enthusiastic with it. The glow plug came out reasonably easily and I compared it to the replacement I bought ~ looks the same. Started screwing the new one in and got to just before it was fully home and there was a bit of an odd feel to the socket .. like something had given. Removed the socket and the electrode looked like it had been pushed out of the centre so I carefully started to remove the plug.

Here's where it gets really nasty  :x  the element has separated from the body of the plug and is now stuck in the hole. Can't see any way to extract it ... BUMMER!!

Does anyone know a way to get this back out or do I have to take the head off? I haven't dared to try the others yet  :o

I've cranked it over to see if the compression will blow it out ~ no luck (but the engine started ok).

What are the dangers of driving the car like this? I'm thinking I don't have time to do a head off job myself at the moment and it's about 5 miles to my tame mechanics place. Am I running the risk of totalling the engine by driving that far?

Any help would be appreciated.

[beast5680]

tough one that there is the possibility when the engine gets hot it will blow out on its own under pressure but when i,ve had injectors and the like snap before on other engines its been a case of head off and use a punch :roll:

[Range Rover Blues]

I can't visualise which part it is that bust off, but I think he's right.  Aluminium expands almost twice as much as stell, so it'll certainly be loose once it's hot.

Thing is if it does blow out, does that mean the job's done?

I can't see if falling into the engine given that it was tight going in with a socket.

[RichardM]

I had this happen to me.  I drove about 400 miles and the snapped off part didn't move at all so I took the head off and used a punch to remove it.

[SteveGoodz]

I had this happen to me.  I drove about 400 miles and the snapped off part didn't move at all so I took the head off and used a punch to remove it.

Richard, did you have a thread going about that on the forum. I thought I remembered someone had the same problem but when I did a search I couldn't find anything.

Can the end of the plug fall into the cylinder or is the hole that it pokes through smaller than the body of the element? The reason I ask is because on very close inspection the new plugs I bought don't have as well defined taper at the tip as the originals. My thinking is that if the hole that the plug goes into is tapered at the bottom that would explain why the element bottomed out before the threads. If this is the case then the tip now stuck in there can't drop through into the engine and do nasty things to the piston/bores/etc. ~ and I'll be a happier bunny  :D

[SteveGoodz]

Today I removed the remaining glow plugs and tested them using my jump starter and they all glow cherry red within 6-8 seconds, so they're okay and not the cause of my poor starting. Whilst this is good news it still leaves me with about an inch of element stuck in the head  :(

Taking a much closer look at the new glow plugs today I can now see that the taper at the end of the element on the new ones are not as sharp as the originals. I've emailed the supplier to get his views as they were advertised as for the 300Tdi and if he's sold me the wrong ones then he's likely to be paying to have this one removed .. whether he likes it or not!

So the difference in shape and the fact that the element of the new one bottomed out in the hole before the threads were fully home kinda suggests that the bottom of the hole is also tapered to accommodate the correct ones. If this is right then the new one won't be able to drop into the cylinder because it's too fat at the end ~ which is some consolation anyway.

So, what has been causing the starting problems? Well about 5 or 6 weeks ago I noticed I was getting gurgling noises from the heater matrix and it was suggested on here (and elsewhere) that this was probably a blown head gasket. After jet washing the engine yesterday I noticed a smear of oil on the block immediately below the head gasket so I guess that's the problem. I'm waiting for my tame mechanic to let me know when he can have it in to sort out. He now has 3 jobs instead of the one we originally spoke about last week ~ crankshaft rear oil seal, head gasket and glow plug removal. Not what I need just before Christmas  

I'll post back when the jobs are done.

[SteveGoodz]

I can't visualise which part it is that bust off, but I think he's right.  Aluminium expands almost twice as much as stell, so it'll certainly be loose once it's hot.

It's the element part, which is about 1 inch long

Thing is if it does blow out, does that mean the job's done?

I can't see if falling into the engine given that it was tight going in with a socket.

Hopefully, yes, except that the head is going to have to come off anyway to replace a blown gasket (see my recent post). I also tend to think it can't fall into the engine ~ but I'll be keeping my fingers, toes and other paired body parts crossed anyway  :D

[Range Rover Blues]

The good news is that a new head will only cost you £300, I've just done 2 and the first one cost me a few quid to get skimmed, I didn't have it pressure tested though.  The second one had a glow plug snapped off in the hole (no.1, what a coincidence) and the last injector wouldn't come out, so I couldn't have it skimmed and went for replacement.

The glow plug had snapped just below the hexagon head, ie the threaded part is still in the head.