OM 603 Injector heat shields
 

When I had the injectors out this winter to satisfy my urge to clean or rebuild them i consulted the board.

I got two points of view on when to replace the heat shields.

Never, they are not moving parts and they will last forever.

or

everytime you remove an injector as they are a crush washer meant for one use.

I have to side with replacing them if you pull an injector.

another angle
 

upside down

and new.
 

this is how much they crush.

om603 injector late response
 

I looked at your photographic observation of the washers new and old. Thank you for your input, it was helpful.

I am considering doing something to smooth out my 87 603 and took one apart tonight. After a close inspection with a microscope, I could see nothing worn or otherwise with the injector body or the few internal parts.

I would consider also that the (heat shield) or (crush washer) to me I would call them "seals" could only be a one time use deal and should be new replacements every time an injector is removed, my opinion. Anyway, what prompted you to consider rebuild or clean the injectors? Was your engine running rough?

I'm going to do pretty much the same thing as you and see if there is a difference with mine, it is running loud and a bit rough. If I find not much or any difference with the injector cleaning, I'm thinking about new hydraulic lifters and if not that..........well the list can go on and on and after a while I'll have a new engine!

My engine has about 170K, (soon to go into an 87 300d) and is currently in my 87 300sdl which is well worn inside and out! The 300D is showroom but has a cracked head.

The decision to replace or not has always been easy for me. I pull the injectors and then can't get the heat shields out so Icrank the engine over a few times. Blows the shields right out all over the place and I can never find them so they have to be replaced!
Seriously, they aren't free, but they are cheap enough to do on general principle. Oh, and my new '86 SDL has the original 014 head and 213k miles on it, with green antifreeze to boot! I feel like I should be praying for that engine in church or something.
Sooty: what color interior? If you part out the car, I may wanna buy some stuff.

I just changed one injector on my 87 300SDL and couldn't get the washer out. I never thought about cranking the engine and blowing them out. Next time I'll do that.

On a side note related to cost, I was flabbergasted by the dealer here. I called them for a price since I also had to replace an injector line. THey wanted to charge $11 for the washer (!!!!!!!). I bought the injector somewhere else who charged me $1 for the same washer. THen, joke on me, I opened the injector box and there was one included.

But thanks for the tip on removing the washer. I'm not getting any leaking around it, so no big worries...

- Ted

FSM procedure 07.1-230 "Removal and installation of injector nozzles" indicates that you are to replace the heat shields (called nozzle plates in the FSM) whenever you pull an injector.

"Nozzle Plates"
 

Call them what you want I suppose but I can think of another name to call them if I have to shell out $11. bucks each!!!!

Where did Ted, down there in Maryland, find them for a buck each? Most MB parts up here on the Cape I buy have to come from our only MB dealer and they gouge deep! Somebody mentioned being able to buy the same Bosch injectors at NAPA!

I'll check tomorrow at NAPA and see what's available.

BobK RE: question about interior color and interest in parts from my departing SDL. To give you just a brief history...I bought the car back in early April mainly because it had a decent running engine, transmission, etc., and no cracked head!

I believe the car was never ever cleaned inside and the previous owner used to spit little pieces of tobacco all over the dash, and steering wheel!!! "Gross" dose not begin to describe it! The drivers seat is broken and bent! The back seat area he must have used as a utility bed for probably anything and everything. There was potting soil under the back seat. The headliner is poked through in many places. It's a shame that this car took so much abuse and it left me to wonder what kind of care the engine and transmission had received but I was assured that in spite of the overall abuse, the old man did have it serviced regularly at the MB dealer here on Cape Cod, where he bought it new!

I've already made arrangements for the cars final resting place with a fellow who wants a parts car and he will haul it away as soon as I get the engine and tranny out, this weekend I hope? I drove this car since April this year and as dirty and beat-up as it is, it still drives and feels like an MB should. I even thought about keeping it but my girlfriend told me she'd never ride in it, and I though, hmmmm maybe I ought to keep it!

I'll ask the guy who is taking the car if he has any plans for using interior parts, and by the way, the interior color is basically gray and black and the wood has ultraviolet damage and is cracked and broken in several places too. My guess is that there isn't much that is good....

Sooty Taillight.......................

Sooty,

Down here in Maryland there are 2 places that I have found with excellent prices. THey are both in Northern Virginia. And the price may have been slightly more than $1, but certainly less than $2. I seem to recall about $1.20 actually. EMB Company in Fairfax and Brinson in Vienna both have great prices and service. Brinson's allows me to buy because I do my own work and belong to the MBCA.

R Leo,

I'll take note and the next time I'm under the hood I'll change the heat shield using the new knowledge. I had every intention of changing it, but just couldn't pry it out of there.

- Ted

Try using a 3/8"x3" lag screw. Thread the lag a little into the hole in the shield and pull it all out with pliers. Don't go in too far or you may hit the ball pin in the precombustion chamber.

Those heat shields shouldn't cost more than a couple of dollars each through a WorldPac distributor like Fastlane. I couldn't find a listing for them at Fastlane but they're bound to have 'em. Call and ask.

Here's the WorldPac part number for the 7.5mm shield: D1010-21025

Do you really have to buy the heat shields ??? this is a picture from FastLane and it looks like they are included.....

I've replaced the SDL heat shields a couple of times and they've always come out with a magnet.

Sixto
95 S420
87 300SDL

yeah i replaced my injectors in my 78 300D about a month ago...no siginificant change from the original ones only except i get a little bit of clatter now at lower RPMS but runs a hella lot smoother at +50mph...less sound. i used the heat shields supplied from the bosch rebuilt box from the ones that i ordered ( brass ones) i dont think it makes a difference at all..

anyways, is it good to do an injector pump timing when changing these bad boys out?....perhaps thats whats causing my poor 300D from smoking more than what it was before with the old injectors?..

allen

Next time try checking th Brass Heat Shields with Magnet; I am betting they are actually Steel and plated Brass Colored.