Finally got around to testing, and then replacing the glow plugs.. 4 stuck.

MJGenay

Full Access Member
Joined
Mar 20, 2022
Posts
133
Reaction score
27
Location
Leadville, Colorado
I know this topic has been hit quite a few times in the past. I've pulled 4 plugs so far, the rest seem to be grinding pretty good as I spin them once screwed out but I can't move them up and down at all. Not sure if that is swollen plugs or carbon. The other 4 plugs seemed fine in that respect - no carbon build up. The plugs I have pulled are Beru's. I'm not sure what the remaining are. I only bothered testing the 4 on the passenger side and they all were bad, didn't even bother testing the driver, I'm just replacing them all with Motorcraft plugs. There are two stuck on each side of the engine.

I'm going to soak them with PB blaster repeatedly over the next 24-48 hours and hope that does the trick. If it doesn't, what is the consensus? Pulling the heads is probably at the limit of my abilities so I'm trying to avoid that. Should I buy the OTC puller? Access will be a bear with that I think. Or should I just unhook the IP and turn the engine over and try to blow them out?

I don't love any of these ideas but I'm just trying to plan ahead.

It's a 91 7.3 with the banks turbo.
 

Norark

Registered User
Joined
Nov 12, 2021
Posts
16
Reaction score
33
Location
Arkansas
PO of my truck had installed Autolite GP”s, and 6 out of 8 were ballooned and stuck. I bought a GP removal tool from Leroy Diesel, and was able to get all of them out without breaking. It still wasn’t easy given the limited space under the fuel lines, but I just took my time and finally got them all out.

 

WrenchWhore

Full Access Member
Joined
Jun 2, 2022
Posts
166
Reaction score
154
Location
Lake Havasu City
If it's carbon built up on the tip I wonder how well a small amount of oven clean would work. I'd prefer some type of oil like a penetrant but at this point i'd feel pretty desperate. I've used oven clean to remove carbon from the tops of pistons and it's nasty stuff and will burn you but DAM it works fast and removes large amounts quickly. I'd be temped to shoot some down the glow plug hole while pulling up on them and wiggling back and forth easily and see if any progress is made. Keep us posted on the progress and good luck.
 

MJGenay

Full Access Member
Joined
Mar 20, 2022
Posts
133
Reaction score
27
Location
Leadville, Colorado
PO of my truck had installed Autolite GP”s, and 6 out of 8 were ballooned and stuck. I bought a GP removal tool from Leroy Diesel, and was able to get all of them out without breaking. It still wasn’t easy given the limited space under the fuel lines, but I just took my time and finally got them all out.

I just ordered one of those. Hoping I don't need it but definitely feel more comfortable using that than trying to shoot them out of the hole.
 

MJGenay

Full Access Member
Joined
Mar 20, 2022
Posts
133
Reaction score
27
Location
Leadville, Colorado
If it's carbon built up on the tip I wonder how well a small amount of oven clean would work. I'd prefer some type of oil like a penetrant but at this point i'd feel pretty desperate. I've used oven clean to remove carbon from the tops of pistons and it's nasty stuff and will burn you but DAM it works fast and removes large amounts quickly. I'd be temped to shoot some down the glow plug hole while pulling up on them and wiggling back and forth easily and see if any progress is made. Keep us posted on the progress and good luck.
As logical as it sounds I'm a little leery of trying that. Not sure how that down in the cylinder would go... Thank you though.
 

franklin2

Full Access Member
Joined
Feb 24, 2009
Posts
5,176
Reaction score
1,410
Location
Va
Just be careful spraying all these liquids that may may make their way down on top of the piston. No harm really if they work to get the plug out, but I think I would turn the engine over with the glowplugs out to make sure any residue is pushed out. There is not much room at the top of the piston when it comes to TDC, very easy to hydrolock the cylinder.
 

MJGenay

Full Access Member
Joined
Mar 20, 2022
Posts
133
Reaction score
27
Location
Leadville, Colorado
Just be careful spraying all these liquids that may may make their way down on top of the piston. No harm really if they work to get the plug out, but I think I would turn the engine over with the glowplugs out to make sure any residue is pushed out. There is not much room at the top of the piston when it comes to TDC, very easy to hydrolock the cylinder.
Okay, thank you. I was actually thinking about that last night going to sleep.
 

MJGenay

Full Access Member
Joined
Mar 20, 2022
Posts
133
Reaction score
27
Location
Leadville, Colorado
Puller is supposed to be here mid morning based on tracking. Regarding the hydrolock, do I have to worry about that if I am only using PB Blaster? Shouldn't that be able to be burned up by the motor or do I not understand...
 

Nero

HD Diesel nut
Joined
Jan 3, 2022
Posts
2,240
Reaction score
2,246
Location
OR
Bar the engine over by hand with the glow plugs out first to push out any excess fluid. Takes a little time, but could save you some headache with blowing the engine.
 

gandalf

Senior Member
Joined
Jan 21, 2005
Posts
3,878
Reaction score
1,072
Location
CA &/or Maine
Puller is supposed to be here mid morning based on tracking. Regarding the hydrolock, do I have to worry about that if I am only using PB Blaster? Shouldn't that be able to be burned up by the motor or do I not understand...
The quick answer to your question is YES. You absolutely DO have to worry about hydrolock if you use too much PB Blaster.

Our engines fire because of heat cause by compression in the cylinders. The air/fuel mixture is compressed as the cylinder rises. The air will compress, and there isn't much fuel. When the cylinder is at TDC there is incredibly little space between it and the head. PB Blaster is a liquid, and will not compress. If there is too much liquid, more that will fit in the small space, it will literally stop the engine from rotating further. That condition is called Hydrolock.

As mentioned above, when all is said and done and you have the glowplugs out, hand crank the engine to attempt to clear any liquid from the cylinders.
 

Old Goat

Full Access Member
Joined
Jan 14, 2021
Posts
1,627
Reaction score
1,618
Location
Northern Nevada
The quick answer to your question is YES. You absolutely DO have to worry about hydrolock if you use too much PB Blaster.

Our engines fire because of heat cause by compression in the cylinders. The air/fuel mixture is compressed as the cylinder rises. The air will compress, and there isn't much fuel. When the cylinder is at TDC there is incredibly little space between it and the head. PB Blaster is a liquid, and will not compress. If there is too much liquid, more that will fit in the small space, it will literally stop the engine from rotating further. That condition is called Hydrolock.

As mentioned above, when all is said and done and you have the glowplugs out, hand crank the engine to attempt to clear any liquid from the cylinders.

The Engine sucks in just air, then compresses air.
Then at the top of the stroke, the Injector sprays in the fuel, and it ignites and boom down goes the Piston.

I think you might be thinking this is the way a gas engine works as you typed here:

(The air/fuel mixture is compressed as the cylinder rises.)

Or maybe I read it wrong?

Goat
 

gandalf

Senior Member
Joined
Jan 21, 2005
Posts
3,878
Reaction score
1,072
Location
CA &/or Maine
Opps. Sorry. I guess my timing was off a bit on the fuel entry into the system. No pun intended, of course.
 

MJGenay

Full Access Member
Joined
Mar 20, 2022
Posts
133
Reaction score
27
Location
Leadville, Colorado
Tool didn't arrive. It left our regional facility at 630AM yesterday as normal which normally means its at the post office by 9. Guess they didn't have time to scan it in yesterday, or its lost... At any rate I hope I have it today.

I will remove the 4 GPs that I was able to replace and turn the engine over by hand. Should I put some paper towels or something up by the GP wholes to absorb anything that may come out? Anything I should know about turning the engine over? Should I disconnect the injection pump somehow? Just throw a big wrench on the fan wheel and turn? Which direction?

Apologies for the dumb questions, never had to do this before.
 

Nero

HD Diesel nut
Joined
Jan 3, 2022
Posts
2,240
Reaction score
2,246
Location
OR
Paper towel over the glow plug hole will help catch and absorb anything coming out.
No need to mess with the pump or disconnect anything.
If it's a manual, put it in neutral. If it's an auto, don't do anything.
Just simply put a big ratchet or breaker bar on the big nut at the center of the balancer and bar it over a few revolutions.
Do not use the starter to bar it over. Even with the glow plugs out, depending on how full the cylinders are, it can still hydrolock.

You should be alright, I have faith in you.
 
Top