Glow plug issue

[Benzy351]

I have a 1999 K3500 4x4 extended cab and 8-foot bed dually, with a 6.5 diesel. The vehicle got a dose of bad fuel a long time ago, I have managed to get that issue resolved but it's smoking white on start-up. So, I have started changing glow plugs. I have eliminated the obvious possibilities of water in the oil, cracked head, etc. So, here's what's happening.

Once I got into this, I realized that only 3 glow plugs were even connected. Not sure they were working either. Started on the driver's side and replaced the front two without issue. The 3rd and 4th on the driver's side both have the following issue:

When I put the socket on it and give it a twist it feels like it's turning, however, when I reach in by hand the only thing turning is the 6-point part of the plug (Collar maybe?) just spins. Holy moly this kinda freaked me out. But I didn't force things. Tried the 4th and it did the same thing.

I have managed to replace 5 of the glow plugs so far and have reconnected all of them to the relay. This reduced the white smoke dramatically. I can start now and let it idle for a minute or so and its clears, unless I punch it. After is gets up to operational temp it's fine.
Not sure how I'm getting them out unless I tear this down and drill them out.

Of course everything else would need to be upgraded if I tear this motor down.

I bought this truck new and it's got around 220,000 miles on it.

Suggestions?

Thanks,
Dave

[arveetek]

When I put the socket on it and give it a twist it feels like it's turning, however, when I reach in by hand the only thing turning is the 6-point part of the plug (Collar maybe?) just spins. Holy moly this kinda freaked me out. But I didn't force things. Tried the 4th and it did the same thing.


Can you physically see the hex portion turning, but the spade where the wire hooks onto is staying still? If so, that is a failure I've not heard of. The threads of the hex are connected directly to that portion of the body of the glow plug.

It's not uncommon for the plugs to swell at the tips, causing the plugs to jam and not come out of the hole. I would suspect that what is happening is the plugs have rotated out far enough to disengage the threads from the hole, but the swollen tips are keeping them from coming any further out, which would make it seem like just the top parts of the plugs are moving. However, the whole top of the plug should be turning.

If that's the case, then you will need to pry the plugs out, or search on how to remove swollen glow plugs. There are even tools made to extract swollen glow plugs.

If you left the plugs loose when starting the engine, I'm surprised the compression of the engine didn't blow them out of the holes....

Casey

[DmaxMaverick]

Welcome aboard!

I agree with Casey. Sounds like the GP tips are swollen. If so, cylinder compression or combustion won't usually blow them out, although I try that before putting tools on them. Sometimes it works, but most of the time, not. There are tools available to pull them out, but it's best, most successful (and ultimately what is most often required), to remove the injector. Plug the flash hole (in the pre-cup), break off the tip, push it back into the pre-cup, then retrieve it with a magnet or blow it out with shop air.

Ideally, the plugs should be extracted and replaced. However, if there's only 1 or 2, I'd not mess with them. The engine will start, as you've seen, without all the plugs working. Extracting swelled plugs is not without risk that can require a more complicated repair (or overhaul). If it comes down to a coin toss, and the old plugs win, just tighten them back in and put up with a little bit of smoke. The EPA won't like it, but they don't like you already.