The great OM616 injector heat shield mystery
 

From what I can tell, there are two, possibly three, different types of heat shields that can be found in an older 240D. I'm hoping some folks can weigh in on this topic, and specifically, what kind do I have!?

Standard Heat Shields:
These are the kind you get when you order new injectors. They have a 10mm aperture. These are definitely NOT in my Benz.


Original RE-USABLE Heat Shields (?):
Post #6 mentions this reusable shield. As the photos from this post are pretty identical to my photos, I'm assuming this is what I have. The aperture is about 6.5mm, as best as I can tell. I have tried PB, pounding on them with a wooden dowel, with a piece of steel, cranking the engine, a hook from underneath. They will NOT budge. I have yet to try the suggestion of screwing a 3/8" lag bolt into the aperture and prying them out that way. I'm nervous about gouging up the mating surface with the injector.

"Top Hat" Heat Shield:
Post #30 has nice pics of the difference between this style and the 10mm heat shields. Is this "top hat" style the same as the "re-useable" style? I do not yet know.

Here are photos of my prechamber. It does appear that there is some kid of heat shield installed. I'm just not sure how the heck I'm going to get them out to figure out what kind they are. What do you think? If they are the "reusable" ones, should I just leave them in there and not worry about it?

Hope y'all are having a happy Memorial Day weekend!:D

One of our member said he could not get out the Heat Shelds till he scraped the Carbon off of the insided diameter above the heat shields.

The newest Heat Sheilds are backwards compatiable.
Simply look up your Year and Model at your favorite Parts Seller and use those.
See post #2 perhaps the Prechamber on the left in the pic is for the Top Hat type Heat Shields
http://www.peachparts.com/shopforum/diesel-discussion/337338-injector-heat-shield-removal.html

There used to be a disposable Heat Shield with a 5mm Hole and the newer ones have a 10mm Hole.
When pulled the Injectors out of My Car back in 2007 it had the Heat Shields with a 5mm Hole. The place I bought them from only sold the 5mm holed ones at that time.
Since that time they have been selling the ones with the 10mm Hole.

You can still get the ones with the 5mm Hole but you need to buy them for a VW Rabbit or Volvo Diesels from the 1980s.

No one has explained why the change was made from 5mm to 10mm.
Someone did have a good idea and said if your Injector Nozzles are used and you had the 5mm ones when you re-insall them use the 10mm ones because they will be seating on smooth unused part of the Nozzle.

I had the same ones as you in your picture. I sprayed some WD-40 on them to clean up the carbon and used a pick to remove them and replaced with the new larger style. No issues with leaking fuel.

there is a lot of rust in your picture... can you clean all that out? I'd use pb-blaster or some decent penetrating oil to fix the issue, then the shields will come out easier.

You can buy Kroil penetrating oil on Amazon. It's the best penetrating oil that I've found.

Yeah I tried TONS of PB, then I whacked on them with various objects--wooden, steel, flat, pointed. What finally worked was screwing a threaded object into the aperture and that was able to give me some leverage to pry them loose. I read somewhere a 3/8" lag bolt fits nicely for that purpose. I just used these implements that were lying around my workspace. The big screw on the left was probably not the best idea, as the threads kind of shaved off and might have fallen in the hole...

Anyways, MYSTERY SOLVED! The short solution is:

if a pencil won't fit in the hole, that means you have the old top hat heat shields in.