How F am i? Cross threaded injector threads in prechamber

[betito123]

Hello, everything was going fine until today when taking an injector off and trying to put it back in it wont go in. I discovered the upper threads were completely gone and cross threaded. Will i need a new head?
The image is here: https://files.fm/f/g3k629z24r

[t walgamuth]

Ouch! I suspect if you can locate him there is a guy out there who can fix it.

[t walgamuth]

What engine is it please?

[Sugar Bear]

I think you could just replace the prechamber and the injector, no?

[betito123]

Originally Posted by Sugar Bear

I think you could just replace the prechamber and the injector, no?

How hard is it to remove the prechamber?

[Diesel911]

Originally Posted by betito123

How hard is it to remove the prechamber?

First the big warning that I myself forgot. The glow plug has to be removed before the prechamber comes out.

If your prechamber retaining ring has 2 big slots for the removal installation tool the injector threads are in the retaining ring and a new ring is the fix with its new threads. And there is no absolute need to remove the prechamber from the cylinder head.

If your prechamber is splined as in the below ad the Injector threads directly into the top of the prechamber. Remember, if you remove the prechamber the glow plug is the first thing to come out.

https://www.taiwanautotools.com/Product/Detail.aspx?id=1331

[JHZR2]

Originally Posted by betito123

How hard is it to remove the prechamber?

Thread in the slide hammer, after removing the glow plug, and hammer out. Not a big deal if the threads are ok. Thing is, even the slide hammer can damage the threads. The angled injector setup isn’t great for removal. The threads are weak.

I’d chase the threads on the prechamber. And be prepared to have to cut new ones and use some kind of adapter to hammer it out.

[Diesel911]

Originally Posted by JHZR2

Thread in the slide hammer, after removing the glow plug, and hammer out. Not a big deal if the threads are ok. Thing is, even the slide hammer can damage the threads. The angled injector setup isn’t great for removal. The threads are weak.

I’d chase the threads on the prechamber. And be prepared to have to cut new ones and use some kind of adapter to hammer it out.

One would think that there is a Mercedes special tool out there for the stripped thread issue. But maybe not.

It is hard to pick what to do when you are not there.

In theory if the threads were nonexistent if your adapter has long enough threaded area someone could get a skinny arc welding rod and weld it to the lip of the prechamber.

The other option is to rethread the inside of the chamber and make a puller adapter to thread into that.

Another option is removing the cylinder head and driving the chamber out.

[betito123]

Originally Posted by t walgamuth

What engine is it please?

It is an OM602 engine.

[greazzer]

https://www.reddit.com/r/W201enthusiasts/comments/18q8nm9/om602_turbo_prechamber_removal_was_a_success/?rdt=48967

[vstech]

I have several 602 heads.
I THINK they all have prechambers that can be replaced when damaged.
I have the pc removal tool as well...

[vstech]

Be sure to remove the glow plug first...

[Diesel911]

From your picture you have the splined retainer and that means it is the top of the prechamber that is stripped. The puller uses the threads on the prechamber to screw the tool into to pull the prechamber out.

The question is going to be after the glow plug is removed and the retaining ring is removed if there is enough threads left to allow the forced needed on the tool to pull the prechamber.

Post number 1 has a picture of the prechamber tool and the thread sizes.
Question About Precombustion Chamber Pulling Tool

One way to go would be at blast with an air gun to get any chips out. Put a small rage in the bottom and degrease the stripped area with brake cleaner and do the same with the proper end of the puller tool. (After the glow plug and the retainer ring are removed.) Coat the inside threads of the prechamber with slow curing JB Weld and the threads on the puller. Screw the puller in and just tighten it a bit. Give it the full cure time like till the same time next day. If it is cold out, you need to find some way to heat it to at least close to room temperature in order to cure the epoxy.

Laser Tools is an English Company that has tools made for them in China. From the ones I have used would say they tools are good quality. They are sold on US eBay.

[alexiseayy]

I’d chase the threads on the prechamber. And be prepared to have to cut new ones and use some kind of adapter to hammer it out. krnl.fun
hdstreamz apk

[Diesel911]

Make sure the glow plug is removed and the prechamber retaining collar before you start.

suggestions. Make sure your auto club is such that you can get 2 fee tows.

You go to autozone or someplace where you can get the free rental slide hammer, the large one. You need like a 5 pound weight.

You take the long saft part of the slide hammer to the hardware store and find a Rod Coupling which is essentially a long nut that will fit the slide hammer. See the attached pic. The far left one is a rod coupling.

You take the rod coupling and if you need to grind or fil off a small portion of the hex corners on one to fit inside of the prechamber. Attached is a mockup of that in the middle picture.

You need to discuss what you want done with a welder. You tow the car to a welder. The welder welds the Rod Coupling to the prechamber where I put the red lines but of course all the way around it.

After the weld cools enough to solidify while the prechamber is still hot thread the slide hammer into the Rod Coupling and use it to pull out the prechamber.

When you pull it out it will look something like the last picture.

Note that the per-chamber pictured is from a 617.952 and it may be slightly larger. I am not very good at welding and I think there is enough room for even me to get inside there and weld it