Will it run?

[Moose McAlpine]

My memory from around 2018 was that it was just the ceramic tip.

I've not looked this time around. I was reminded by the fact that I'd wrapped that plugs bit of the loom in a load of insulating tape.... I spotted that and realised that I never dealt with it at the time.

It may've swollen and stuck in the bore. The only real way of removing that without pulling the head is to fit a compression test adapter in place of the injector, pump in compressed air and drill out the glow plug tip.

Alternatively screw in a glow plug with the end cut off, to plug the hole.

Otherwise its head off and drill/punch it out.

I have a whole bunch of tools for glow plugs, but they're all for the body and not the tip.

 

[Barking Mat]

Run it up, remove the broken base plug, when it starts running funny on 3 cylinders it's spat it out.

 

[Moose McAlpine]

Run it up, remove the broken base plug, when it starts running funny on 3 cylinders it's spat it out.

I've done various versions of this with injectors and glow plugs.

It's errrr.. "exciting" when they come loose.

 

[julianf]

The only real way of removing that without pulling the head is to fit a compression test adapter in place of the injector, pump in compressed air and drill out the glow plug tip.

I was thinking of this, and was trying to compare the pressure of a firing cylinder with pressurising the cylinder with compressed air.

I couldnt think up the right words to use in google for the pressure, as i kept just getting standard (non combustion) compression data back.

I mean, my compressor goes to, what, 10 bar - you would imagine an explosion in a cylinder to be greater than that, but maybe not?

I forget what thread the injectors are on the 300. Ill need to look it up.

How reliable have you found this method to be?

 

[Barking Mat]

I was thinking of this, and was trying to compare the pressure of a firing cylinder with pressurising the cylinder with compressed air.

I couldnt think up the right words to use in google for the pressure, as i kept just getting standard (non combustion) compression data back.

I mean, my compressor goes to, what, 10 bar - you would imagine an explosion in a cylinder to be greater than that, but maybe not?

I forget what thread the injectors are on the 300. Ill need to look it up.

How reliable have you found this method to be?

I'd squirt atf and acetone in the hole, run the engine up, and wait, if it doesn't come out at temperature, then it's head off.

On a good long run.

 

[Moose McAlpine]

I was thinking of this, and was trying to compare the pressure of a firing cylinder with pressurising the cylinder with compressed air.

I couldnt think up the right words to use in google for the pressure, as i kept just getting standard (non combustion) compression data back.

I mean, my compressor goes to, what, 10 bar - you would imagine an explosion in a cylinder to be greater than that, but maybe not?

I forget what thread the injectors are on the 300. Ill need to look it up.

How reliable have you found this method to be?

Pumping the air in is to blow debris out the cylinder if you're drilling the plug out. It won't dislodge it, peak combustion pressure in diesels can often be up to 3,000psi.



This is an old screw-in dummy injector for compression testing, i've used it with an airline connected for drilling out plugs. It does blow all the crap at you when you break through though.

I've found it reliable in my use. I've removed a lot of glow plugs through various methods and the most i've had to do is helicoil damaged threads.

 

[Barking Mat]

Pumping the air in is to blow debris out the cylinder if you're drilling the plug out. It won't dislodge it, peak combustion pressure in diesels can often be up to 3,000psi.

View attachment 344775

This is an old screw-in dummy injector for compression testing, i've used it with an airline connected for drilling out plugs. It does blow all the crap at you when you break through though.

I've found it reliable in my use. I've removed a lot of glow plugs through various methods and the most i've had to do is helicoil damaged threads.

That's interesting, I've a 1.5 BMC where I've done exactly the above, broken glow plug, I'll try that one day. Top tip.

 

[julianf]

.

View attachment 344775

This is an old screw-in dummy injector for compression testing, i've used it with an airline connected for drilling out plugs. It does blow all the crap at you when you break through though.
.

I know virtually nothing of other engines - the injectors on the 300tdi only have thread to fix to the high pressure pipe work. They're clamped in.

Maybe all engines are like this. Really the 300tdi is the only one I ever get involved with.

I presume I'd either need a scrap injector or a turned dummy unit with an attachment for an airline on the top?

Thank you.

 

[Moose McAlpine]

I'm not familiar with 300TDIs, but i know one of my compression tester kits has a stackable adapter for various injectors. Not sure why i assumed they were screw-in.

Having a fitted adapter isn't at all essential, just easy. You don't need much pressure, just airflow to blow the debris out so as not to allow it into the cylinder. A blow gun down the injector hole with a rag stuffed in around it will do just fine.

 

[knighty]

you could jam an airline in with a rag or but of rubber etc...

you don't need super high pressure in there, just enough to blow swarf out


personally I'd just ignore it, can't imagine it coming out with that much force

 

[sako243]

It'll run.

My 300tdi still runs with one of the pistons having a chunk out of it.

Mine drove from at least North Wales to South Wales with a snapped crank whilst towing a Bridgeport.

 

[mtt.tr]

Mine drove from at least North Wales to South Wales with a snapped crank whilst towing a Bridgeport.

The virtues of not overly strained engines, not fast but plenty to keep working

 

[owas]

Rocker shaft snapped and still got me home

 

[sako243]

Luckily this crank snapped just infront of #1 hence why it could still drive

 

[8ob]

300tdi glow plugs are very long and thin, I have found that the easiest way of getting snapped off glow plugs out is to hollow the chalky gear out of middle of them with a small drill welded to a bit of rod, this allows the case to shrink a tad and they will normally come flying out when you run the engine

Bob.

 

[reb78]

What have you decided to do Julian? Taking the head off if needed isnt the biggest job in the world on these - just time consuming if you arent so familiar with the process. I did my 200tdi head gasket over a relaxed weekend.

I would always be too worried about drilling out in situ, even with air going into the cylinder, that a fragment would not come out and wreck the cylinder bore.

 

[sako243]

For comparison I've done a head gasket change on my 300Tdi in well under an hour, but I've done a fair few and at the time (forgotten now) even knew all the torques off the top of my head.

 

[mtt.tr]

Rocker shaft snapped and still got me home

View attachment 344805

Seen this a few times,last one pushed the rocker caps off no damage to valves

 

[julianf]

Had it running today. An interesting start -

New lift pump, connected to the fuel tank, pumped using manual lever - spat out some brown slime, and then the pump blocked.
Reverse blew it out with air line (which i didnt think was actually possible) and then connected some temporary hose to a jug of clean fuel.


New filter, and then to the IP, which also hasnt been run in years. Left the injector connections loose, and the same brown slime appeared at them on turning the engine over.

It became a toss up between burning out the starter or chancing the bad fuel, and, after some cycles of cranking for a bit, and then waiting, we connected the injectors up and gave it a go...


It started, but unstable revs. Which isnt unexpected when theres air in the system, but the revs wouldnt drop back properly when the IP arm was released back. Ie would rev up and not drop back to idle properly.

We were considering this after a few goes at starting, when the engine went into run-away, and, just as i got to the ignition cut, it suddenly dropped back to an entirely stable, smooth idle.


Starting and stopping now as well as any other 300 ive had and entirely stable idle.


Hypothesis -

Governor in ip stuck either because of, or independent of, rotten old fuel.


When i poured out the jug at the end of the job, there was the same brown fuel at the bottom that id seen in the tank, so i guess the pump was full of it also.


I drained the tank from the sump plug (i think the tank is one of the newest parts of the truck - every other part of the 110 is dented, but i could see no damage to the tank at all, so it must be new (there's been plenty of other bits bent underneath the vehicle, so there's no chance its the original tank at all).

I dont have a good plan to flush it, beyond what ive done - drained it, then poured jugs of fuel in, and let them drain again, and carried on doing that (they keep coming out again brown, so im certainly flushing something).

At the end of the day, i put the plug back in and a couple of jugs of fuel in to try and soak it a bit, and then ill drain again, and see what its like.


The front hubs are in bits at the moment, and all the wings etc off, but its not so very far off an MOT now for the first time in years. So not a bad days work.

 

[julianf]

What have you decided to do Julian?

Probably leave it till after the MOT to decide!