I am in the process of removing my glow plugs to conduct a compression test. I don't believe the valve covers have ever been off and the seven BERU glow plugs I have removed were tight but once I "cracked" the pressure, they spun out easily.

An additional fact that might be relevant is the glow plug in the #7 cylinder (passenger rear) had white smoke when running (before I took the glow plugs out).

When I went to remove the glow plug from number seven, it didn't "crack" open but instead has constant pressure (as if it was cross threaded). I have heard of other brand glow plugs "swelling" but my guess (and it's only a guess) is that this glow plug is also a BERU.

I can keep turning the glow plug but I'm concerned that I would do damage - including having it snap off (though it has not stopped at this point - it's just hard to turn with my socket).

Does what I am encountering sound like a swollen glow plug? If yes, how should I proceed?

As a final observation, the seven glow plugs that I removed were covered in oil and smelled like burned oil (yes - I know they are glow plugs). I assume that was just residual oil trapped around the glow plug but I'm not sure. If/When I get #7 out and conduct the compression test, I'm worried I'll get sprayed with oil. Again - advice is appreciated.

 

A shop vac with a small hose works well for pulling the oil puddled up around the glow plugs, before pulling them of course.

Technique probably depends on exactly how tight the plug is binding. Threading it back in a fraction of a turn and resuming CCW rotation repeatedly may help, but it could work harden the plug (possibly) until it snaps.

Whatever the case, don't make the threads hot by turning too fast or to much at once. A lot of heat can generate quickly on the surface of threads galling the crap out of them.

I have no experience dealing with a swollen plug, but generally with threads of all types this is the rule of thumb.

 

Thanks. How do I know if the glow plug Is truly stuck? I’ve got two or three turns on it but I don’t even know if it is threading out. I just know something doesn’t feel right. Being #7, I can’t really even see if it’s unscrewing.

Since I’m in Southern CA, I don’t really need glow plugs. If it is “stuck”, would screwing it back in even matter If I decided to leave it in place, assuming it doesn’t break off and fall into the cylinder (which it hasn’t done in the 8 years that I’ve owned the truck) what harm would there be? For example, would I not have a seal on #7 and thereby lose compression?

 

If you have a GPR and not a GPCM I'd thread it back in and just run 7 GPs. As you mentioned, you hardly need them in Socal. If you have a GPCM you'll need to fix it otherwise a bad GP will throw a code and you cannot pass smog.

Compression check on the other 7 should provide some good context. If they are all over the place then #7 doesn't matter, you have a problem anyway. If they are all good it gets trickier. Once all the GPs are back in disconnect the 42 pin harness so it won't start, then crank it over and listen carefully. The cranking RPMs should be steady. But if RPM varies it's because a hole or two is lower in compression, allowing the RPM to speed up when those get to compression stroke. But that is just listening and interpreting sounds, not nice numbers from a compression check.

If the threads in the head are galled up and leaking put some oil around the GP. If it's leaking compression the oil will psst right outta there when cranked.

 

Was the engine stone cold when you removed the glowplugs? Glowplugs can and will snap between the head and the body where the threads are, especially if they have never been removed before and the head is cold. I had that happen to me on a Dodge Sprinter. It sounds a lot like one of the previous owners snapped the glowplug and left it in. What you are probably feeling is the head and inner element of the glowplug spinning inside the body of the glowplug and not actually applying torque to the threads to spin the rest of the glowplug out. Like @aawlberninf350 said, you can probably just leave it in since you are in SoCal but you will have a GPCM error code.

 

Last December I changed all 8 of my glow plugs when I installed my new turbo. I tested them and told myself if I had 3 or more bad I would change them all. Turned out I had 3 bad and so I changed the GP's, the gaskets and the UVCH's with OEM parts. So, for the previous 6 years, my truck had been starting within a second or two after sitting for extended periods of time with only 5 working GP's. I never would have known the difference if I hadn't seen it for myself. I can honestly say that there is no discernible difference 5 working and 8 working GP's in a warm climate like GA during "most" startups. I do have a GPR light and will time the light or wait until it goes off in the dead of winter if I am starting the truck though.

As the fellas mentioned above, I would turn it back in and leave it there. If you do have a GPCM, just know that you might see the code there and it is a known issue and you can move on. Having 7 working GP's will be plenty good in CA.

 

Thank you.

First, I have a GPR - not a GPCM - as mine was originally delivered in WA.

Second, the truck was cold (65F) when I removed the glow plugs. Should I replace the seven glow plugs and heat the engine up and retry? If yes, should I first use the remote starter to turn the engine over to remove the fluid that entered the glow plug holes or is it not enough to worry about? I’m guessing I should try to set the valve covers on top to prevent fluid shooting up.

Third, if I’m not turning the threads on #7, should I even try re-torquing the plug? As was suggested earlier I would of course check for fluid escaping #7 when I replace all glow plugs and start the engine.

Thanks again.

 

My apologies. My understanding was that all Excursions are equipped with GPCMs.

There shouldn't be enough fluid in the cylinder to worry about hydrolock but turning it over with the other glowplugs still out is cheap insurance.

Yes, getting the engine warm will help IF the head on glowplug #7 isn't snapped already. Just tuen it very gingerly after warming the engine up. If it is broken, no amount of warming up or turning the glowplug will help. You will have to resort to one of these if you really really want to take it out:

Glow Plug Removal Remover Tool 16 Pc Set 8mm 10mm Plug

 

I think you are right but I don't see where he has an excursion. I'm wondering if he doesn't have the socket binding on the rocker arm and causing the problem.

 

Yup. I got him mixed up with someone else.

 

Guys,

I need a sanity check.

I took your advice and tightened the flow plug in #7. That’s in and staying there.

I warmed up the truck for 15 minutes and all other glow plugs have been removed.

i removed the 42 pin connector and ran the remote starter to the starter solenoid on the fender.

I proceeded to try testing compression With the HF setup but am getting no reading on the gauge on 1 & 3. I can see puffs coming out of the other cylinders.

see attached picture.

what am I forgetting?

 

Did #7 glowplug tighten and stop or did it keep spinning? If it tightened, then it's not broken and you should be able to remove it.

Are the other cylinders giving you readings? If so, what are they?

 

didnt try since the first two were zero. Didn’t want to run down the battery/starter.

 

Check to see if the ORB adapter has been ground down enough to get all the way down into the glowplug hole. That o-ring needs to seal.

 

Same result in drivers side 2

my setup does not use a Schrader valve. I’ve got the m10 in the glow plug hole with a female 1/8 NPT that goes to the grease whip that then goes to a 1/8 FNPT to a male 7/16 flare fitting that goes to the quick coupler that goes into the compression line.