Glow Plug Fun

[Ashley Burton]

So the fun continues!

Tapped a M6 thread into the body of the remaining glow plug. Screwed a nut & bolt into the thread & it's just stripped the thread straight out

My next thinking is to drill the remaining part of the glow plug & fish the tip of the glow plug out through the injector

Any other thoughts before it becomes a cylinder head off job?

 

[frank horton]

wot u said last I'm afraid.....

even heard of an heat plug with a big thread breaking...new head was the answer to that one.....
sorry.....modern vehicle gremlins again...

 

[Ashley Burton]

@frank horton Do you think the drilling method would work or is that more trouble than it's worth?

 

[gaz1]

is there anyway you can get a blow lamp down and use it to preheat the plug

weve been known to do that but you need a deflector to stop the spread of the flame more so if near an aluminium block

the deflector acts as a point of heat

 

[Ashley Burton]

is there anyway you can get a blow lamp down and use it to preheat the plug

weve been known to do that but you need a deflector to stop the spread of the flame more so if near an aluminium block

the deflector acts as a point of heat

I think I would struggle tbh

It's an aluminium head

I've got a feeling the glow plug tip has carbon build up potential on it

 

[tom2207]

this is going to sound silly ,,, but here goes

chase the threads to get a bit of a grip again , thread in a long bolt , or a bit of thread bar


now the silly bit

knock it in a wee bit , just a wee bit ,,,,,,,,,, dont try to pull it out.

the knocking it in will , with luck break the carbon build up and get a mill or two of movement , then plenty of injector removal spray , its specially formulated to dissolve carbon , then keep workin with it trying to work it out
told you it would sound daft , but its not that daft when you think about it , you can get lot more power hitting it than pulling it to get that break away.

 

[Ashley Burton]

this is going to sound silly ,,, but here goes

chase the threads to get a bit of a grip again , thread in a long bolt , or a bit of thread bar


now the silly bit

knock it in a wee bit , just a wee bit ,,,,,,,,,, dont try to pull it out.

the knocking it in will , with luck break the carbon build up and get a mill or two of movement , then plenty of injector removal spray , its specially formulated to dissolve carbon , then keep workin with it trying to work it out
told you it would sound daft , but its not that daft when you think about it , you can get lot more power hitting it than pulling it to get that break away.

Its worth a try!

Got nothing to loose apart from having to remove the cylinder head

 

[tom2207]

Its worth a try!

Got nothing to loose apart from having to remove the cylinder head

well your heading towards that any way ,, so as you say , nothing to loose ,,, its hard to think of knocking it in to get it out ,, but it makes sense when you think about it ,,, ish .
best of luck.

 

[Ashley Burton]

@premmington @m_c @Ruffian What's your thoughts?

 

[Melvyn Best]

Have you tried starting the engine ? Cylinder pressure may blow it out especially if you give it a good squirt of air intake cleaner

 

[armalites]

There are special kits with drill guides to allow you drill to the edge of the thread then pull the remains out.

 

[doubleboost]

https://www.ebay.co.uk/itm/Broken-G...056431?hash=item2f4c450c2f:g:i2oAAOSwumNfilV~
loads of kits on the bay

 

[Ruffian]

Worcestershire sauce,
Heat of the engine and a decent drive.
To get it nice and warm.

Did it with 1.6hdi peugeot.
Took 20miles but did fire out.

 

[Ashley Burton]

The glow plug thread isn't the problem:

I'm starting to think I need to get a deeper thread cut into the long body

The thread I cut was getting tight, So didn't force it as I didn't want to snap the tap in the glow plug

@Melvyn Best Already tried running the engine & using the pressure of the cylinder to push it out. But sadly no effect!

I'm also tempted to thread the top part of glow plug back in & take it for a good drive to see if it helps it out. Just don't want the glow plug shooting out & doing any other damage

 

[Ashley Burton]

@Ruffian I think it's worth a go!

 

[premmington]

I have several kits that will extract the broken parts of a glow plug.

I have also seen and are contemplating buying a "portable spark eroder". While it is a long job - it does save a lot of hard work.

 

[8ob]

The glow plug thread isn't the problem:
View attachment 259385
I'm starting to think I need to get a deeper thread cut into the long body

As you have the others to measure I would try drilling guts out of that glow plug, once all that chalky gear is drilled out the casing may relax a bit, you could then tap it and attack it with a slide hammer. Nothing to lose at this stage.

Bob

 

[doubleboost]

The extractor kits are not expensive
If you start poking drills down the hole it will end in tears
I make good money repairing threads etc that have been got at

 

[a111r]

What's the engine?
Merc CDIs are the worst for this nonsense...

 

[premmington]

What's the engine?
Merc CDIs are the worst for this nonsense...

Real later Merc engines have a sleeve with an allen key hex in them - you snap the glowplug - then withdrawer the glowplug with the sleeve with an allen key.

The problem is: The tiny glowplugs have no strength in them - 8mm diameter is too thin.

There is so little spare space in a modern head with all the multivalve - the glowplugs have to be so long and thin to find the way to cylinder chamber.

Anybody bought any glowplugs with pressure sensors built into them - they cost the earth.