Bent Glow Plugs

caladash · Mar 16, 2013

Doing injectors on the truck and when I was taking the glow plugs out to bar the motor over all the drivers side glow plugs are all bent. Not the heating element but the body. Don't know about the passengers side yet but what would cause this? I have ZD-11s installed with about 50 thousand miles on them. Not the cheapos. They weren't to hard to come out just required some needle nose pliers to pull them out. Hooked them up to a battery and they still work. Would it be bad to reuse them?

Blowby · Mar 16, 2013

If they are bent or damaged in any way replace them.

Viking · Mar 16, 2013

Blowby said:
If they are bent or damaged in any way replace them.

THIS

caladash · Mar 16, 2013

Luckily I had some spare ones set aside. Also noticed the part of the plug that the harness plugs into is loose inside the body. Gonna post some pics once I'm done. Cleaning up the passengers side.

Justin@DP-Tuner · Mar 17, 2013

Hmmm. I have never seen a bent body of a glow plug. Got any pictures? Not sure how it happened, but like stated above, just replace them.

caladash · Mar 17, 2013

When they were installed they were torqued properly as well. Both sides were trashed.

907DAVE · Mar 17, 2013

Crazy!

Viking · Mar 17, 2013

I have no idea!!! WOW

Have you ran a compression test before?

oldschool · Mar 17, 2013

is possible that they were torqued by ft lbs instead of inch lbs? looks like they were overtightened?

mandkole · Mar 17, 2013

Not sure what a cross-section of a GP bore looks like in the head, but almost looks like they were crushed between the bottom of the GP case (at base of heating element) and the threads--

Bobby@cp · Mar 17, 2013

caladash · Mar 17, 2013

Haven't done a compression test before. When they were torqued I used an inch pound torque with a fresh calibration done on it. When I was in the marine corps,my first enlistment, I was a Metrologist! Still have access to the cal lab!

Justin@DP-Tuner · Mar 17, 2013

Wow! Maybe the glow plug bodies were not made correctly. If they were a little too long, I guess I could see that happening.

JLDickmon · Mar 18, 2013

sumpthin like that..
got another "spare" you can compare overall length with?

caladash · Mar 18, 2013

"Spares" are installed. Came off a spare motor i have.

Justin@DP-Tuner · Mar 18, 2013

Maybe go down and buy a new one, and compare it to the old ones? If they are in fact longer, you may want to get a hold of Motorcraft.

907DAVE · Mar 18, 2013

How would being longer affect this. The sealing portion is at the very bottom of the glow plug.

Vader's Fury · Mar 18, 2013

Even if they were longer, You would still have to over torque them to distort them like that.

They would just bottom out sooner.

jaybuller · Mar 18, 2013

mabey so much cyl pressure it just pushed them up while running hard? neevr seen this or heard of it though. Thants wierd. but it does look to me like they were just tourqued down to hard at one time.