Changing Glows -what to expect?

[warmblood58]

Been driving '80's Mercedes diesels for quite some time and have done many glows BUT never a 7.3 IDI. My big fear is I will discover broken Autolite or worse - I have new Motorcraft ZD9's on the way. So any words of advice before I undertake the job and what if I do discover a broken glow, what is the procedure for this? I will be anti seize on the glow threads - anything else to know? Thanks All!

 

[Dieselcrawler]

http://members.shaw.ca/k2pilot/Glow plug removal article.html

 

[warmblood58]

Great advice and read, everything I was looking for - we shall see if I am lucky! Thanks again!

 

[icanfixall]

When doing glow plugs its important to really look closely at a broken or missing plug tip. If the tip is missing and it has some soot on it don't worry. the piece that burned or fell off is now gone out the exhaust valve or stuck in the piston top. This the plug broken off piece that you remove is shiny then you just broke off that tip. Getting it out has several ways too. One is to start the engine and rev the hell out of it.. I do not recommend that way. Some poor guy had a shop change out his plugs and thats what they did. When he picked up hir truck it had a knock... He asked whats going on... they told him that will pass... A few tips broke off and they are bouncing around but will blow out in time.... Well that shop ended up nearly replacing that engine. Valve job and pistons were the parts needed to repair that engine.. Reading up here all you can will help you get thru this usually simple job. Have a can of Aerokroil on hand. Its sold by the Kano Labs and they have a great web site.

 

[dgr]

1/4" drive ratchet with a swivel unless your IP lines are off. I wouldn't anti-seize the glow plugs. I believe they are stainless into cast iron. Mine were still shiny when I pulled them and no corrosion. Maybe the diesel dripping on them kept them in good condition?

 

[73idi88f350]

1/4" drive ratchet with a swivel unless your IP lines are off. I wouldn't anti-seize the glow plugs. I believe they are stainless into cast iron. Mine were still shiny when I pulled them and no corrosion. Maybe the diesel dripping on them kept them in good condition?

i put some on mine to make sure they come back out.. no probs with it...

 

[smolkin]

When I replaced mine last month, I had 2 get stuck after the threads had cleared the head. I used the split-nut trick to get them out- I heard about it here, but I don't recall from whom. Just go to your local hardware store and get a nut that fits the plug thread, then saw it in half and vise-grip the halves around the exposed threads...then gently continue with the ratchet. Worked like a charm. I also used a product called Rust Buster that I got from the A/C supply store, and let them soak for 2 days before. Just letting you know what worked for me, all 8 (5 Autolite, 3 Beru) came out without breaking. The DieselRX dual-coil replacements are also doing great, but time will tell with those I guess.

 

[Boston]

I used the autolite GP's before I was informed about the troubles associated with them, and am not to keen on trying to get them out. The suggestion was made that an ether system works like a charm anyway, so I'm just planing on going in that direction and abandoning the GP system. Seems like a lot of people have trouble with both maintenance and poor quality parts in this system anyway and no sense risking a tear down every time a glow plug fails.

Just throwing it out there as it seemed like a viable alternative. My only concern is that maybe these tips will disintegrate even if just abandoned and damage something anyway.

 

[dgr]

While Beru is clearly the championed plug here, there are others not running them and doing so successfully. But it's heresy to say more and I kinda like it around here even with all the religion.

 

[whiteboyslo]

I replaced what had to be the original glow plugs in my truck a few months back. I used Motorcrafts. Nothing overly difficult; every one came out with ease. 1/4" ratchet with u-joint and deep 6-pt socket (I forget the size) is your best friend here. The only issue I had was the ceramic/plastic connector on the ends of the harness were very brittle, so some fell apart. I used 14-16 gauge bullet connector adapters that I found at the local parts store to replace them. These ones had a bit of shrink wrap built into the opposite end, which was handy. No problems whatsoever.

Only other thing I'd recommend is to vacuum the heck out of the area surrounding the plug before you pull it. Seems to accumulate a lot of dirt/grime and you probably don't want that in your engine.

Mike

 

[warmblood58]

All great advice guys and I feel like I know what to do and have several alternatives should I encounter the dreaded (won't even say it) situation. Will report back!

 

[Danielle]

Just did mine also, definitely had to vacuum. Some 1/4 drive skinny extensions got me between the lines. Just be careful what you sit on hee hee. Don't ask!

 

[RLDSL]

Use antisieze, reduce listed torque by 12% which isnt a whole stinking lot with a iddy biddy inch pound torque wrench, if you dont happen to have an in lb torque wrench ( which you REALLY should ), it works out to BARELY taught with one hand on a 1/4 drive ratchet . This is one of the main reasons that glow plugs get siezed so many times. These gorillas get in there and go flex monster on the wrench thinking that the glow plug is going to vibrate out, not realizing that it takes VERY little torque to seat something in firm and solid on a taper seat. Look at the torque specs on aeroquip hoses, they sell very short, easily bent wrenches to tighten their fittings , just to keep folks from overtightening the taper seats
With a thread torque, uou are stretching teh thread to pull the fastener down , but with a taper seat, you are runing dead up against the taper, you cant go any further, to try to do so distorts the threads and jams the plug, then when you go to try and remove it after thousands of miles , add soot and varnish, forget it.

 

[warmblood58]

Use antisieze, reduce listed torque by 12% which isnt a whole stinking lot with a iddy biddy inch pound torque wrench, if you dont happen to have an in lb torque wrench ( which you REALLY should ), it works out to BARELY taught with one hand on a 1/4 drive ratchet . This is one of the main reasons that glow plugs get siezed so many times. These gorillas get in there and go flex monster on the wrench thinking that the glow plug is going to vibrate out, not realizing that it takes VERY little torque to seat something in firm and solid on a taper seat. Look at the torque specs on aeroquip hoses, they sell very short, easily bent wrenches to tighten their fittings , just to keep folks from overtightening the taper seats
With a thread torque, uou are stretching teh thread to pull the fastener down , but with a taper seat, you are runing dead up against the taper, you cant go any further, to try to do so distorts the threads and jams the plug, then when you go to try and remove it after thousands of miles , add soot and varnish, forget it.

I agree and thank you for the reminder!

 

[smolkin]

Just be careful what you sit on hee hee. Don't ask!

I've found a 4' stepladder set up right against the bumper is your best friend. A short 1X12 board also makes a good "seat".



That is, unless you like a 4" steel hook where it don't belong...like being a pirate's wife when the ship's in port...