I just changed mine yesterday. Remove the wheel, easy access to the front 2, to do the rear 2 I pulled off the down pipe. Yea the rear 2 are a real treat.

Check the wires for supply voltage while you do them...

Oh & yea might consider to warm the motor up before hand & then also leave the block heater plugged in. My front PS GP would not come out, threads must be galled...that one I left alone.

 

Check the wires for supply voltage while you do them...

What is best way to do that? I assume you stick the + probe of your voltmeter into the wire and the - to ground and turn the key on but won't the controller just cycle the juice on and off? Or do you have to turn the key 8 times to test all 8 wires?

 

When I did mine, after removing the inner fender, I removed the heat shield and the metal tubes that surround cylinders 4 and 6 glow plugs. They are bolted onto the exhaust manifold. After that, access was very easy. I think that I had to use a universal joint for gp# 6 due to the manifold being in the way. After reinstalling the metal tubes, I had to use long nose needle pliers to reattatch the wires because you can't get your fingers in there to plug them back in. It has been a while since I did them so I can't remember how the heat shield comes off, but I don't remember it being that difficult. Make sure that you use anti-sieze on the glow plugs so they will be easier to remove next time you have to change them. Good luck.

Steve

 

PS Glows

When I did mine, after removing the inner fender, I removed the heat shield and the metal tubes that surround cylinders 4 and 6 glow plugs. They are bolted onto the exhaust manifold. After that, access was very easy. I think that I had to use a universal joint for gp# 6 due to the manifold being in the way. After reinstalling the metal tubes, I had to use long nose needle pliers to reattatch the wires because you can't get your fingers in there to plug them back in. It has been a while since I did them so I can't remember how the heat shield comes off, but I don't remember it being that difficult. Make sure that you use anti-sieze on the glow plugs so they will be easier to remove next time you have to change them. Good luck.

Steve

Yep, works great, did mine couple months ago, about 3 hrs.

 

Yeah, I had an idea I was going to hear heat shield and downpipe related responses.

Thanks guys.

The DP should be fairly easy to remove as I have a joint now at the bottom where it meets up with the rest of my Diamond Eye system. 2 Studs at the bottom and the clamp at the top and it's loose.

Those who removed the heat shield(s), did you bother putting them back on? Looking at some of the bolts I have my doubts I'll successfully get them off without shearing the heads off the bolts in question.

I had planned to replace all the wiring as my stock stuff has seen better days..and install a GP override at the same time since I'm going to be putting in 60G's which require the extended glow times.

Was just talking to fellow member Racer55 (whom has the GP's I'm buying off of him) and he once again graciously offered the use of his most awesome workshop...so it looks like we have a project on Saturday.

As always, lots of pics and video will follow.

Any other pointers or suggestions that would benefit us would be great.

I guess since I can't currently even get to (or see) the GP's on the PS I'll just randomly soak down the whole area and hope some runs down onto the GP's to start the process of loosening things up.

 

Thank you for asking the question that I was too embarrassed to ask a month ago!! I managed to get 5 of 8 done.. but gave up for the other 3. Was going to wait until we get some warmer weather..

 

When I did my glow plugs, I noticed that the wires on the pass. side are very small, not sure exactly but maybe 16-18 gauge, definately smaller than the drivers side. Is everyones wires the same as mine? They look factory but don't seem as if they would carry the current for the gp's that well without a lot of resistance.

Steve

 

I was looking at the PS wiring this afternoon myself and thought the exact same thing.

I think I'm going to simply disconnect the factory wiring from the GP controller to the actual GP's and run new wiring instead. If I remember right the 60G's draw about 13 amps each and I gotta figure that's a stretch for the factory wiring. Not sure how many amps the original GP's would have drawn, but I gotta figure much beyond 10 amps tops for those little wires would have been a stretch.

 

I did mine when I did head gaskets. They were easy going into the new head on the bench lol. I remember the heat shield was bolted to the vc n it was a tight fit going under the turbo on my 93.

 

When I changed mine (years ago), I put it up on my lift to put them at eye level once I took the tire and inner fenderwell off. Not to bad a job then.

I recommend testing your new ones before you put them in, and test your old ones when you take them out.

Good luck,

 

The old ones have caused me lots of grief for 3 winters now. I have plenty of things in mind to do with them once they're out, aside from testing them. :

 

True, but I was curious as to which ones worked. Very easy to test on your battery, or jumperbox is what I used.

 

Agreed, I was just being silly...I will probably test them purely out of interest once they're out. I think they're original 9G's still in the truck and aside for at least 1 that's not working because it's actually disconnected (broken wire on one PS one) last I checked I had only a few that were still registering as functional.

 

If I remember correctly, I went through several beers doing mine!

 

Just changed 7 of mine yesterday, 1 would not come out, it got left in, it's dead in the hole.

Testing the old ones I had 2 that tested good...

It started a whole bunch better this morning...

My Injectors are next hoping for spring though

 

I kick myself for not just buying GP's and having them replaced when I had my injectors put in a few years ago... I paid to have that job done (just did not have the time) and of course that would have been the simplest time to have it done at minimal extra cost.

Hindsight is always 20/20 I guess.

 

So FWIW I went out this eve and sprayed the bejesus out of the PS cylinder head area as close as I could get to the GP's. I really soaked it all and tried to spray it in such a fashion that hopefully enough will run down onto the plugs themselves and start loosening things up. I'll do the same a few more times tomorrow and Friday - won't be restarting the truck until Saturday.

 

Wow, here I am thinking you moderators know everything about the 6.5s and here you are looking for help. Just goes to show how complex the 6.5 is IMO, and what a useful resource this site is.

 

Being a mod doesn't mean we know everything. I'm not embarrassed to ask for help when I need it - I'm not a diesel tech or anything - yeah, I'm familiar with the 6.5 but by no means do I know everything, either.

 

I did not take my inner fender out I did remove the heat shields and the passenger side tire the only one I really had an issue with was the #8 starter was in the way took a half hour on that one

 

Heat. the new ones will glow after couple seconds. DO NOT TOUCH the pretty red metal. It burns lol

 

I think you can test them with a ohm meter too, but I'm not sure what the values are, or if it can be done once they're removed

 

I think I read somewhere that over 2 ohms is too much. I'm not sure how exactly you test them, or where to put the contacts because I tried testing my old ones with an ohm meter and couldn't quite get what I wanted.

And privatepilot, what a coincidence I just put my 60Gs in Tuesday I have had my inner fender off more times in the last 6 months than I can count so I took that route of course. I took my front tire off, batteries, air intake, battery tray, then inner fender. I was able to keep the heat shield on this way. It is kind of a pain getting back in with everything together, but still possible. There are tabs on it that make it much harder ha. Once inner fender is out the job was a piece of cake. Plus mine came out really easily, only 100k on them plus I had em out a month ago for my compression test. I didn't have to take my downpipe out (in my case, its a pain). I have small hands so I was able to get around my 4 inch downpipe to the last GP Anyways best of luck to you!

 

I just received a set of Bosch plugs from Rock Auto for $59. Already got the drivers side plugs removed in under 10 minutes. We'll see how hard the passenger side is tomorrow. This is in a '92 C3500HD, so will there be more room to work, what with the raised body and all? And I'm not sure why everyone is making a big point of spraying the old ones with penatrating oil. I didn't bother and got mine out with a little 1/4 inch drive socket wrench. Plus the body looks like stainless steel, the threads were all rustfree and the factory torque spec is just 13 ft. lb.

 

And I'm not sure why everyone is making a big point of spraying the old ones with penatrating oil. I didn't bother and got mine out with a little 1/4 inch drive socket wrench.

Search for "broken glowplug" in the 6.2 / 6.5 forums and you'll find plenty of horror stories. THIS is why everybody makes a big deal of it - if they break off in the head (as they've been known to do) you have a problem.

I'm hoping I'm just blowing this out of proportion, but after a few years worth of reading horror stories here about GP replacement on the 6.5, I've got myself all convinced it's going to turn into a nightmare.

Sometimes I need to remember that for every horror story posted here, probably 50 other people have replaced their GP's with no issue but don't post "success stories" on the forums...so you only read about the bad, and rarely the good.

 

I changed mine in about 45 mins I did not have to remove anything I just cut a small hole in the passenger side inner fender and got to the one that I had to cut the hole for. I broke the driver side one that is 2nd from the front I didnt even try to mess with it I just pluged it back in and all was fine. It broke the hex part off and the connection was still there so I wasnt going to mess with it. It was as easy as changing spark plugs in a old 350 gas motor.

 

The glows only draw about 10 amps a piece. That wire's fine. I believe it's fusible link wire, which is why it's smaller like that. The smaller gauge makes it the "weakest link" in the circuit, so if anything goes wrong that wire fails, preventing a fire.

Don't re-wire it. Leave it be.

As far as removing the heat shields. I didn't take mine out. I used a deep 10MM socket and an extension and removed the GPs that way. I pushed the wires back on with needle-nose pliers and that was that.

Proper Ohm reading for a working glow plug is 0.8-0.9 ohms, in other words, less than 1 ohm. I've had some read 10 ohms, some read 20+, and had one that was constantly changing ridiculous values(think 1K ohms and up) on the meter. Those ones never even got warm when I put power to them.


Mark if it makes you feel any better. I worked on a 94 that plowed snow for 200,000 miles. All 8 came right out. My blazer sat for 10 years in a field, all 8 came out, although two were swollen(one very badly) and took work with vice grips to remove. MY pickup i changed them at ~160K, all 8 came right out.

Did the glowplugs in a friends 6.9 IDI, all 8 came right out, and those glowplugs sit vetically near the intake runners, meaning the area around them collects water and they rust into the heads.

If any of your glowplugs do not want to come out, don't just yank them out. A tip snaps off and it either gets to violently meet the piston repeatedly, or your pulling the head to get that piece out if you can't fish it out from the pre-cup by removing the injector.

 

Mark if it makes you feel any better. I worked on a 94 that plowed snow for 200,000 miles. All 8 came right out. My blazer sat for 10 years in a field, all 8 came out, although two were swollen(one very badly) and took work with vice grips to remove. MY pickup i changed them at ~160K, all 8 came right out.

Yes, I keep coming back to what I said yesterday - for every horror story we read about here, I must keep in mind a million other people had no issues.

My problem is that I'm the poster boy for Murphy's Law.

I'll heed your advice on the wiring so long as I have power at all the wires - I know at least 1 on the PS is now dangling loose and a few others look like they've had a rough few years.

 

You have to be careful when leaving the relay on constantly.

Some relays aren't designed for constant duty use. They are designed for intermittent duty.

The intermittent duty relays are usually the high current ones(like ford starter solenoids) that if left on for long periods, even with no load will burn up.

I had one that i tested this theory on. I turned the relay/solenoid on and just left it on. No load on it at all(save for a test light across the "high" side to check for power on both sides of the solenoid). 5 minutes later it was dead, and so hot i couldn't touch it. It never worked again and i threw it away.

 

I should have noted that, yes, I'd disconnect it immediately after completion of the test. Given the correct prep work ahead of time (all wires disconnected from the glows and accessible) the testing of all 8 while the relay is jumped could be done in 30 seconds or less.

I will +1 on the hot relay though - I have a generic 150 Amp relay wired up in our Fifth Wheel to power an inverter and it DOES get hot when closed constantly, even with no load through it. It depends on how the electromagnet is designed inside the relay, some are better then others at being left in the energized state than others when it comes to heat generation.

 

I'm working on the passenger side plugs right now. Front and second one were pretty easy to get to. From the top for the first one and through the wheel well where part of the splash shield is torn off. I just finished removing the #3 plug and that was a little more complicated. I took the wheel off just to have more room to work. The problem is the turbo pipe is very close to the shield or tube around the plug:

You can't get a needle nose pliers in there to pull the wire connector off the plug and you don't want to tug on the wire either. Used one of these tools to pull it off:

Then to remove the plug I used a deep 1/4 drive 3/8" socket and u-joint:

That unscrews the plug but won't get it out of the hole. You have to remove the u-joint from the socket, use a piece of coat hanger inserted in the back of the socket to push the plug out of the socket, remove the socket from the hole and then with a magnet fish out the plug.

I can only imagine how hard it's going to be putting the new one in.

 

OK, got the new #3 plug in, seemed too easy. You can't just put a deep socket on it as it won't fit in the tube because the turbo pipe is in the way. I was able to use clear plastic hose soaked in boiling water to make it more flexable, attached it to the plug, then I could get it into the tube to start the threads, pull off the hose and finish tightening with the socket.

On to #4.

 

You are using aintiseeze on them threads I hope...

 

Nope, the old ones came out real easy even with a 1/4" drive wrench, there is no mention of antiseize in the manual, and I'm not sure how much it would interfere with the grounding of the plugs.

 

All right I got the last one passenger side rear, replaced. Wasn't too hard, easier than some cars with that one difficult to reach spark plug. You have to remove the coolant reservoir, then you can snake your left arm along the firewall around a wire harness and a/c line to pull the electrical connector. Then you can place the socket on it. Next go underneath with the socket wrench to break it loose, you have to stretch your arm to reach it. Then go back up top to remove it with your fingers on the socket. It's a good idea to have the new plug right there ready to go so you don't loose sight of where it goes. Then just tighten from the bottom again. Now to test for voltage at the connectors.