Stripped injector base?

[Brian VT]

I was driving home from the dump and climbing a long hill and I noticed I was putting out more smoke than usual.
But I figured it was maybe from the LiquiMoly Diesel Purge I had added to my fuel before I left.
Then smoke started coming into the cab.
So I pulled into a parking lot and 3 of my injectors on the driver's side were soaked with fuel.
I wiped them off and started the engine again and one of them is spraying fuel out at the base of the injector.
I wasn't far from home so I had my wife bring some tools. I tried to tighten that injector but it wasn't getting tighter.
I decided to drive it home and made it with no fire and went straight to the beer fridge. Then here. Ugh.

Before I dig into fixing this...what are the odds that the injector threads are stripped and not my head threads? Those injectors seem to be made of pretty stout metal. So I'm afraid of finding out the worst news. And then what?

 

[chicken bones]

The injector has a crush washer , only to be used once. Torque to 34 ft lbs.They have too be seated properly or they can leak & let combustion gasses pass. I recently change my injectors , I did have to get one replaced because it was leaking . Very odd that three would just start leaking if you have'nt touched them.

 

[Brian VT]

I replaced them about a month ago. Been fine until now.
Anyone know if the injectors are softer metal than the heads? Has anyone here dealt with stripped head threads on an IDI before? (in case I find that mine is stripped)

 

[asmith]

I haven't heard of stripped injector threads in the head before, but that doesn't mean it cant happen. Usually it is a poorly seated washer, or a double stacked washer. Sometimes guys forget to get the old washer out before putting the new one in. Sometimes there is a lot of carbon build up in the holes and you have to clean the seats off before the washer will sit properly. One thought is maybe you had some carbon build up down in the hole, and the washer was sealing, but since you used the diesel purge, it has cleaned some of that out of there so now it is not sealing as well.

 

[Brian VT]

I did hook the old washers out before installing new ones but I didn't clean the seats for fear of getting crap down the hole. So I like your theory that maybe carbon on that seat got dissolved and caused the leak and the loose injector. And I can't promise that the previous owner didn't have 2 washers down there and I only got one out. I figured that since I got 8 out that I was good to go.

I'm still pretty nervous as I believe in the parking lot I probably got a 1/2 a turn on that injector and it still wasn't tightening up.
I guess I'll find out when I dig into it. For now I decided to just sulk and drink beer and wonder how to fix head injector threads. :-(

 

[gandalf]

You say that you tried to tighten the injector, and it wouldn't move. That doesn't sound like a stripped thread. My best bet would be the copper washed. The 3 possibilities that come to mind are: 1) the washer somehow isn't seated properly, 2) you forgot the washer altogether, 3) you double stacked the washer, you forgot to remove the old washer and put a new one in on top of the old one.

 

[Brian VT]

You say that you tried to tighten the injector, and it wouldn't move. That doesn't sound like a stripped thread.

I could turn it fairly easily with my 1" wrench (after loosening the fuel line nut). It just didn't get any tighter or seat. As I said above, I think I probably got at least 1/2 a turn on it and it still didn't feel tighter. So I gave up trying to fix it in a parking lot and drove it home.
That's why I'm wondering if some threads are stripped. Or whatever changed down there was thicker than 1/2 a turn of the injector threads?

 

[Austin86250]

If it was stripped wouldn’t it always have this problem? Vs just appearing now

 

[chillman88]

Stop doing what I do and worrying about maybes! I lose more sleep that way!!

What did you torque the injectors to on install? If you're really worried about it I personally would try to remove it and inspect it before trying to crank it down. Honestly just because I'd be afraid of making it worse by tightening it more.

I wouldn't lose too much sleep though, you can probably helicoil it if the threads pulled from the head.

Nothin to it but to do it unfortunately. Good luck!

 

[Brian VT]

If it was stripped wouldn’t it always have this problem? Vs just appearing now

Good point.

FYI, I didn't torque my injectors when installing. I do have a torque wrench but couldn't figure a way to apply it. I went "firm" and then tightened if they leaked. Same with the line nuts.

Another aside. I have new injector lines from Accurate Diesel waiting to go in. That's why I didn't mess with this one injector tonight. Because if I start into this then I'll be changing all the lines (and I guess I will then have new leaking o-rings, etc.) and it just wasn't in the cards for me today.
And...I'm wondering if my 1st order of business is going to be installing a helicoil. That's my main reason/concern for starting this thread.
Luckily, I have a backup vehicle to drive while the truck is down.
It sounds like stripped head injector threads aren't very common so I will try to hold positive thoughts on the matter.

 

[Nero]

If the injector wasn't torqued correctly, it may have backed out, then the two halves of the injector may have unthreaded. Only real way to tell is to uninstall it and take a peek. Having raw fuel come out makes me believe the injector nozzle retainer has come loose, or it cracked.

 

[Jesus Freak]

There's another engine in Maine with a C6 for sale....... might be good to have an extra in the bed just in case this happens again.

 

[Brian VT]

If the injector wasn't torqued correctly, it may have backed out, then the two halves of the injector may have unthreaded. Only real way to tell is to uninstall it and take a peek. Having raw fuel come out makes me believe the injector nozzle retainer has come loose, or it cracked.

Good info.! Thanks.
So the bottom half of the injector might be ready to drop off into never-never land? (I'm not sure how they go together)

 

[Jesus Freak]

then the two halves of the injector may have unthreaded.

I think this would be an extreme worst case senerio. Those things are tough to get apart.
Don't scare him to bad, he's already started drinking!

 

[chillman88]

They're supposed to be 35ish lb/ft so if they were just snugged up then they probably did back off. I torqued mine to 40 with antiseize and still had one loosen up. You're probably fine, I'd pull them out and make sure the body is tight before putting them back in. Technically you should probably replace the copper washers now since they're technically used now.