Glow plug tip stuck

[snodge182]

Hi all,

I have a 2007 Zetec S 1.6TDCi and I was giving it a service the other day. I decided to change the glow plugs as the previous owner had bought some and not done it. When trying to get the left one out (the one closest to the drive belt side, number 4 I think), I heard a lot of creaking and it wasn't particularly easy, before it released. When it came out the tip was not with it, and a wire was coming out of the end where the tip should have been. I realised that the tip must have become seized and stuck in the engine so I chopped the wire off and put the glow plug back in (I understand if that wire touches any metal part of the engine during operation then the glow plug circuit would short.

Long story short I need to extract the tip from inside where it is seized. I have called a garage who said because I've been using it still then the tip has probably fallen into the cylinder and the engine is f***ed. However if it hasn't they should be able to get a specialist to extract it, costing £130 to extract the seized tip, and £100 for any other seized glow plugs.

I've bought a borescope which should be coming tomorrow and I'm just wondering, if I was to remove that glow plug again (the one with the broken tip), and turned on the engine, would the explosions in that cylinder blast the tip out?

I know this is a tricky situation to be in, and its all dependent on if the tip is still there or if it has fallen into the engine (is there any easy way to determine this by hearing the engine or loss of power from that cylinder or something?). I know one method of testing that is to see if there is any air coming from that glow plug hole, to see if the tip is still in it or not.

Has anyone had any experience with this kind of thing?

Any help much appreciated 🙂

[TomsFocus]

Vacuum is created as the piston is pulled down in the first second when you turn the engine over, if you've run the engine at all, the tip will almost certainly have been sucked in.  

If you've got a whole plug stuck, you can use the compression stroke to pop it out, but it's too big a risk with just the tip imo.

If it's still running, the damage can't be that bad though...  If you're really lucky and it's a very small piece, it might have been blown out of the exhaust port...although it will probably now be stuck in the turbo instead.

 

[snodge182]

On 10/15/2020 at 7:56 PM, TomsFocus said:

Vacuum is created as the piston is pulled down in the first second when you turn the engine over, if you've run the engine at all, the tip will almost certainly have been sucked in.  

If you've got a whole plug stuck, you can use the compression stroke to pop it out, but it's too big a risk with just the tip imo.

If it's still running, the damage can't be that bad though...  If you're really lucky and it's a very small piece, it might have been blown out of the exhaust port...although it will probably now be stuck in the turbo instead.

 

Thank you TomsFocus

It would appear that the tip is really jammed in the 4th cylinder, I'm going to see if the other glow plugs come out without snapping to assess how bad this issue has extended.

I measured the resistance over the other glow plugs and they have a very large value, I plugged the electrical contacts from them and the car starts as normal so I'm wondering if any of them work at all.

Would you have any tips for removing the other glow plugs without snapping them? I've sprayed them in WD40 and turned them very slightly to hopefully penetrate with the WD40.

I also bought a borescope and had a look, there is a lot of black powdery carbon build-up around the snapped tip.

I hope no damage comes from all this :S

 

Also, if I spray WD40 into the hole with the snapped tip at the end, will it be bad for the engine?

[TomsFocus]

WD40 isn't the best penetrant for this sort of thing as it dries out too quickly, just touching the top of the threads.  A little bit of diesel or veg oil dripped in is better as it'll 'ooze' down the threads and won't dry out at all.  If that's not possible, try some Plusgas instead of WD40.

Ultimately though, if the plugs have been there that long, the seal will be air tight and you won't get any penetrant falling deep down enough before you make the first turn on the plug, which is probably the one that'll snap the tip.  You'll need to remove the head to get the broken tip out anyway so the correct course of action would be to clean up and apply penetrant to the inside of the plugs before attempting to remove any more.  I'm sure you know already but just 'wiggle' the plugs back and forth if they get tight to loosen any contaminants rather than going for a massive turn in one go.  And lastly, always keep the ratchet straight, don't allow any angle on it at all as old plug tips will just snap if sideways force is put on them.

Any WD40, Plusgas, diesel etc that falls inside the engine won't cause any problems at all.  It'll just burn up next time it's run.  Large pieces of carbon, rust, grit or especially plug tips falling inside the cylinder should be avoided though.

 

As the plug tip has remained stuck inside the head since running, you could try to run the engine with that plug removed in the hope of popping it out.  It is a big risk though and I don't take any responsibility if it goes wrong lol.  Obviously don't put your hands or face anywhere near it while running...  

[snodge182]

On 10/20/2020 at 10:37 AM, TomsFocus said:

WD40 isn't the best penetrant for this sort of thing as it dries out too quickly, just touching the top of the threads.  A little bit of diesel or veg oil dripped in is better as it'll 'ooze' down the threads and won't dry out at all.  If that's not possible, try some Plusgas instead of WD40.

Ultimately though, if the plugs have been there that long, the seal will be air tight and you won't get any penetrant falling deep down enough before you make the first turn on the plug, which is probably the one that'll snap the tip.  You'll need to remove the head to get the broken tip out anyway so the correct course of action would be to clean up and apply penetrant to the inside of the plugs before attempting to remove any more.  I'm sure you know already but just 'wiggle' the plugs back and forth if they get tight to loosen any contaminants rather than going for a massive turn in one go.  And lastly, always keep the ratchet straight, don't allow any angle on it at all as old plug tips will just snap if sideways force is put on them.

Any WD40, Plusgas, diesel etc that falls inside the engine won't cause any problems at all.  It'll just burn up next time it's run.  Large pieces of carbon, rust, grit or especially plug tips falling inside the cylinder should be avoided though.

 

As the plug tip has remained stuck inside the head since running, you could try to run the engine with that plug removed in the hope of popping it out.  It is a big risk though and I don't take any responsibility if it goes wrong lol.  Obviously don't put your hands or face anywhere near it while running...  

Thank you for replying, this is very useful information!

Two of the tips have snapped off, leaving two glow plugs still in there. The car drives completely normally except for now we are getting 47mpg rather than the previous 53mpg.

The other two glow plugs feel very tight and although I have turned them very slightly (not even a quarter of a turn) they are still very tight. When I snapped the second one, it was kind of tight, and then went very loose suddenly (which is when I knew I had just snapped that one also).

Removing the head would be too costly so looking for alternative options.

We did contact a chap who deals with Diesel glow plug removals and he said he can come out and extract them in situ, however we must remove all the fuel lines, egr valve, fuel filter, windscreen wiper assembly and any other items in the way before hand, then he will come out, drill the tip, tap it and extract it. Then we got to rebuild everything we removed. He charges £140 for the first tip and then £100 for every other tip (£440 as we need all of them done). I just don't think I can warrant paying a guy almost £500 for an easy half hour job (I say easy as he has equipment such as the drill and taps etc), while I do all the legwork to get it ready for him. *rant over*

I'm thinking I may be able to drip some diesel fuel/vegetable oil (as you suggest) into the chambers where the broken tips are, let it soak into the siezed tips, then knock the siezed tips into the cylinders and extract them through the injector holes.

[st line x 140 driver]

drill through snapped glow plug use hoover to suck up swarf (to prevent falling in engine) extract with stud extractor. sounds like a hayes manual😁

If threads are damaged use helicoils. replace with new plugs. Easier with the head off.

[TomsFocus]

£140 just for the tip??  I dread to think what he charges for a shaft...  

 

I'm really not keen on the idea of knocking them into the cylinder but if you don't want to take the head off I suppose it's worth the risk.  At least you can make sure it's all out with your borescope before reassembly.

 

[st line x 140 driver]

Personally with snapped plugs its a head off job might even be worth getting reconditioned one. Then replace cambelt too for piece of mind and many more years of trouble free driving from the engine at least.

[snodge182]

So I drove it long distance over the holidays and one of the tips popped out (I had the glow plug shaft out), which meant a horrible 30 minute end of a journey with a very loud, misfiring and smoking engine. Smoke coming in to the cabin and everything!

Parked it up and after removing the injectors (miserably as number 1 and 4 copper washers got stuck and we ended up damaging the injector seats), we found there was only one more tip left stuck in. Removing that was a case of knocking it gently in to the cylinder bore and fishing it out with a magnet on endoscope.

Suffice to say the injector seats being damaged didn't accept the new copper washers so instead of replacing the head we bought a replacement engine (after many people saying its the easier and usually more cost effective option than taking off the head on these engines).

[Bobr]

On 11/17/2020 at 4:05 PM, TomsFocus said:

£140 just for the tip??  I dread to think what he charges for a shaft...  

I'd call that a shaft.