Injector was ejected!!!

bugnout · **Posted:** Tue Oct 20, 2015 10:34 am

#2 injector was ejected from the intake manifold at highway speeds this weekend. Bolt appears to have taken the threads with it. Lots of white smoke, engine continued to run while I got it off the highway. I was a bit worried by this particular injector bolt as I know the bolt had been over torqued above 24 ft/lbs. Everything else held together, when I opened the hood the injector was sitting about 3 inches higher than the other 3 injectors. Plumbing appears fine, hoping that the injector socket is undamaged.

The Jeep is sitting at Diesel Injection in Madison WI right now. They wont be able to look at it until Thursday. Hoping that the threads can be repaired via Time-Sert or similar, and in place rather than having to remove the manifold. Just have to wait until the mechanic can look at it on Thursday.

geordi · **Posted:** Tue Oct 20, 2015 12:13 pm

The threads aren't in the manifold, they are in the top of the head. 90% chance they will need to tear the top end apart to do the repair properly, but I don't see why a helicoil couldn't be used as long as there is enough aluminum there to work with and not find a water jacket.

Sorry for the bad news, but at least it is fixable.

Hexus · **Posted:** Tue Oct 20, 2015 2:56 pm

Helicoil will fix it, I've done it. You must take the intake off though to ensure that you don't get the drill bit aluminum shavings down inside the rockers/lifters/valves/cam area of the intake and head.

Expensive proposition all things considered. I hope you can do this work yourself.

bugnout · **Posted:** Tue Oct 20, 2015 3:51 pm

What do you think about tapping the hole the next size up as a temporary fix? I'd have to find the right bolt, but that should be doable without removing the intake manifold.

papaindigo · **Posted:** Tue Oct 20, 2015 3:56 pm

Perhaps I'm over or under thinking this are geordi and hexus certainly know more about injector pulling than I do but:
1. it's injector #2 so access to the crows foot bolt hole is easy from the top as opposed to say #4
2. if the crows foot bolt does directly into the head as far as I can see it does so in a recess in the cam/valve cover that's totally sealed off from the cams/valves so I don't see how aluminum shavings could get to the cams/valves unless I'm missing something.
3. obviously one needs to plug the injector hole with something to keep shavings out of the piston.

If so just buy a helicoil kit in the proper metric size and go for it. Only possible problem is to what extent is the existing hole a "blind" hole which I suspect it is. In which case getting a helicoil fully installed may require deepening the hole or using a "blind" tap; I don't know if helicoil install blind taps are available although they should be.

Yeh next size up might work but likely would require oversize hole in crows foot.

geordi · **Posted:** Tue Oct 20, 2015 8:25 pm

Right on all accounts - the only difficulty would be in being able to inspect the contents of the hole while working on it. The shavings have no place to go b/c the gasket is in place, so they can only come out the top or fall to the bottom of the threaded hole. It is a blind hole, IIRC, there is at least another 3/8" of depth available below the normal threaded depth, I would use a slightly longer helicoil if at all possible, one that offers at least 1/2" of length to ensure that you can thread it in quite fully and still get the 5 or 6 threads of the factory bolt into the helicoil to hold the injector down.

Packing the flutes of the tap with grease can help with extracting the shavings. Ditto for the drill. I would insert the drill dry, and mark a 1/2" depth on the bit so you know when you have drilled far enough before tapping.

Actually... Thinking about it now... Why not just try a longer bolt in the same factory dimensions first? Catch more threads that aren't damaged below the ones that are, and you might just be good to go! Get a couple bolts that are different lengths longer than the factory one, and see which is the deepest one you can thread into the head. As long as you get at least 5 turns out of it, you will have decent thread engagement for the 24 ft-lb torque. A tap in the same factory size to gently clean the wrecked threads may be helpful too. I can't believe I didn't think of that before.

thermorex · **Posted:** Tue Oct 20, 2015 8:53 pm

I dont see a reason why wouldn't you be able to re-thread, the only disadvantage may be to drill a larger hole for the valve cover to acommodate the larger bolt. I am sure that the cyl head has some extra meat surrounding the injector bolt threads, and also, you have nothing to loose. Worse case you need a new cyl head anyways...

But that makes me wonder, what happens if he taps through both valve cover and cyl head? My logic says that most torquing force would be in the valve cover, do you guys think that the crush washer for the injector won't seal property?

WWDiesel · **Posted:** Wed Oct 21, 2015 3:31 pm

Geordi is dead on about using grease on the drill and tap if you go that route. Done it many, many times...
Another possible fix comes to mind if the hole has some threads below the stripped ones; get a metric threaded stud of the proper threads and long enough to protrude well past the top of the crows foot and install it all the way to the bottom of the threaded hole using red locktite. You can always use some washers on top of the crows-foot to get the proper torque. I have used this trick on many aluminum heads and motors in the past and it works well if there is enough threads left in the hole to hold the stud...
Otherwise, Heli-Coil it!!!
Best of luck, and let us know how it turns out....

geordi · **Posted:** Wed Oct 21, 2015 7:56 pm

WWDiesel wrote:

Another possible fix comes to mind if the hole has some threads below the stripped ones; get a metric threaded stud of the proper threads and long enough to protrude well past the top of the crows foot and install it all the way to the bottom of the threaded hole using red locktite. You can always use some washers on top of the crows-foot to get the proper torque. I have used this trick on many aluminum heads and motors in the past and it works well if there is enough threads left in the hole to hold the stud...
Otherwise, Heli-Coil it!!!
Best of luck, and let us know how it turns out....

Using a stud is an interesting idea - I was thinking to just use a longer bolt, but a stud isn't the worst idea at all - it might actually be better b/c you will know exactly how many threads you have engaged by counting the revolutions. Could be much stronger.

Mountainman · **Posted:** Wed Oct 21, 2015 10:12 pm

geordi wrote:

WWDiesel wrote:

Another possible fix comes to mind if the hole has some threads below the stripped ones; get a metric threaded stud of the proper threads and long enough to protrude well past the top of the crows foot and install it all the way to the bottom of the threaded hole using red locktite. You can always use some washers on top of the crows-foot to get the proper torque. I have used this trick on many aluminum heads and motors in the past and it works well if there is enough threads left in the hole to hold the stud...
Otherwise, Heli-Coil it!!!
Best of luck, and let us know how it turns out....

Using a stud is an interesting idea - I was thinking to just use a longer bolt, but a stud isn't the worst idea at all - it might actually be better b/c you will know exactly how many threads you have engaged by counting the revolutions. Could be much stronger.

Yeah, and that locktite may make the whole mess stronger. I've ran studs in Toyota heads with JB Weld for permanence. Maybe you could fill the top side where the wrecked threads are with JB weld also if you're worried about strength (24 ft/lbs), although it wouldn't be easily reversed :frankie:

geordi · **Posted:** Wed Oct 21, 2015 10:22 pm

I wouldn't JB weld, but there should be plenty of threads under where the damage is. The existing bolts don't go in more than about 5 threads anyway, and 24 ft-lb is really light for torque.

Even the tensioner gets 28.

racertracer · **Posted:** Thu Oct 22, 2015 7:48 am

Jb weld the threaded hole and use loctite release agent on the bolt or some other quality thread release agent

Let the JB weld sit in the hole with the bolt threads soaked in the release agent. Then lightly tighten the bolt till it reaches bottom just before the jbweld dries. Let sit till dry.

I would use the claw foot as a bottoming plate and soak that with release agent also.

There is nothing to lose but lots to gain, if you can't do it ask the mechanic to do it.

Otherwise the head comes off and the repair is done properly.

This has been done before on other stripped threads with success.

bugnout · **Posted:** Sat Oct 24, 2015 10:09 pm

Fixed. Heli-core installed. Fuel return line fittings broke so those had to be replaced as well. Think I'll start carrying a stud and hardware just in case. I don't think any of the others were ever over torqued but I like to be prepared just in case.

racertracer · **Posted:** Sun Oct 25, 2015 6:48 am

Good to hear.

AlamoLiberty · **Joined:** Tue Mar 22, 2011 11:30 pm **Posts:** 9

I also lost injector #2 years ago. My mechanic fixed it with a Helio-coil. After two years, I found the #2 injector bolt had loosened again. #4 injector looks good, clean, and is a pain to work on- so we are going to leave it alone for now. We've already pulled and cleaned injectors 1, 2, and 3. Tomorrow, my mechanic is going to install studs for injectors 1, 2. & 3. We are using Dorman studs 675-338. They are about a half inch longer than the Jeep bolts.
https://www.oreillyauto.com/detail/c/do ... ag0/675338

We will also apply blue loctite on the serrated nuts that will hold down the injector claws.

Ive dealt with 3 CRD libertys that have had major engine issues. Two engines were totaled.
I believe leaking or cracked heads have caused coolant leaks into cylinder 2 due to a head manufacturing defect or incorrect factory torque settings of the head bolts (which caused the head to crack)- meaning- I believe the torque settings FROM THE FACTORY are incorrect as the aluminum head flexes and cracks. I believe these torque settings have caused countless aluminum heads to fail. Then, I believe coolant slowly leaks into cylinders then blows the injector out while driving. It appears that a small amount of fluid can be expelled from the cylinder. But even this small amount of fluid seems to affect and loosen the injectors. A bit of history: sometimes, when I'd first start driving for the day, the engine would die with a hard stop while idling at a red light near my house. This happened often at the start of the day. Another fact: once or twice a month I found my low coolant light on and had to add coolant. Four months ago, I drove my CRD to my mechanic to change the glow plugs. He was busy. He parked it for a month. Upon changing the glow plugs he noticed lots of coolant in cylinder 2. We removed the coolant from the cylinder and started the CRD. Then we flushed the radiator and added a full 33.8 oz bottle of Bar's Leaks HEAD SEAL Blown Head Gasket Repair. We followed all directions. The coolant leaks appear to have stopped.
Hopefully, after installing the studs for the injectors, this will be a good vehicle. I will give an update if problems arise.

AlamoLiberty · **Joined:** Tue Mar 22, 2011 11:30 pm **Posts:** 9

The injector studs installed easily. The bolts that I recommended were about an 1/8 inch too long. We used a hack saw and sawed off about 3 threads. The great news is the bolts ran into the head about twice the distance as the original injector bolt. It makes one wonder why the engine designers used such short bolts. The jeep is now running great and the injector studs are far superior.

Injector was ejected!!!

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