1986 f250 6.9 idi

[ld1986]

Hello all.

Earlier today I was replacing the junk Autolite glow plugs in my 6.9idi, they where put in by a mechanic shop 5000 miles ago. They worked fine, but I didnt want to wait for them to swell. Ive been told to only run the ford Motorcraft plugs, so that is what I've put in. All the plugs came out real easy. The glow plug attached in the image came out with no trouble. I just want a second opinion if it looks like it was just melted (Autolites tend to do that) or if a tiny piece might've broken off? I would rather not destroy my engine

Thanks

 

[MrMarty51]

It appears to me that it was in the beginning stages of melting down.
Others that are mor familiar with the Fords might probably chime in.

Welcome to the forum 86.

 

[WarWagon]

How many miles on the injectors? (Maybe one is pissing fuel.) Any power mods like advanced timing? (Advanced timing can erode glow plugs with a rusty texture. Not color, surface texture of the plugs.) This a turbo engine Banks or otherwise?

 

[ld1986]

Thanks for the Reply's. The engine is completely stock, it was rebuilt 50,000 miles ago(New injectors with the rebuild). I'm assuming everything was gone through during the rebuild. Sadly no turbo, but it has tons of power for being N/A.

 

[Will L.]

Most of us here run the gm 6.2/6.5 on older diesels. Our world learned long ago to only buy self regulated glow plugs to eliminate a he swelling and often the element breaking off inside. Yes you were headed for failure.

Idk if there is a self regulated plug for your engine or not- if no one here or the ford forums knows of one- I suggest you spend time calling tech support of each mfr.
ours is the AC Delco 60 G , which probably is not the same as yours. Bosch makes some as well, but their quality went junk a couple years back.

Before the self regulated plugs, the fleets I wrenched in and my personal- every 30,000 miles they get inspected/ and bench tested. I learned long ago don’t use the he ohms test to verify good or bad. As the element burns off it lowers the resistance. And the material crystalizes it raises the resistance. As you get burn through (which is what you have occuring) it can either raise or lower resistance based on which end burns through first. And yes, 100% yours would have continued burning at that location and the little end would just fall off into the cylinder in time. So EXCELLENT CATCH on your part to not possibly destroy a good engine.

Idk about autolite, but bosch, ac delco, and others are having a problem with knock offs that look almost identical. So only buy critical parts from authorized dealers. Some people make the mistake of thinking plugs are not critical- this is wrong because if they come apart it can destroy the entire engine, so that meets critical imo.

 

[Husker6.5]

Good catch! That plug was headed to a quick, fatal failure from overheating!