Trap Oxidizer Replacement Pipe
 

I am in the middle of replacing the engine mounts. I removed the trap oxidider replacement pipe and the exhaust pipe to access the top mount bolt. There is no gasket between the turbo flange and the four bolt flange on the replacement pipe. Is this right?

There is a thin metal-type gasket at that union - see attached photo from EPC for your make and model
[edit] A 352 098 02 80 is not listed on Fastlane Parts

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How long would a thin coat of high temp gasket maker last?
I have some 28 ga sheet metal and could make a gasket, but then there is the possibility of a leak on either side of my gasket.

Looking at my '87, there appears to be some kind of goop that has squeezed out from between the trap cat replacement and the turbo. [This would have been done at the dealer as part of the trap cat recall campaign.] I don't why you couldn't make a gasket from your sheet metal and use a thin coat of high-temp sealant on both surfaces.

If you're talking about the 87 300D, there's no gasket between the trap replacement pipe and turbine side inlet.

Sixto
87 300D

No gasket
 

EPC confirms (not that we would ever doubt Sixto :D) no gasket. Looks like my dealer smeared some hi-temp silicone on the mating surfaces in lieu of a gasket. I guess the gasket I'm remembering was in the OM617 engine.

Everything is not listed on Fastlane and All Parts Express. Call Lee on the 800#, and he can order.

Charlie

Thanks for the replies. To keep moving a smoothed off both mating surfaces the best I could with file and made a gasket out of sheet metal. It does not appear to be leaking, but there is a lot of air movement in that area from the fan blades.

If the mating surfaces join tightly, the high temp silicone should last indefinitely.

I have done this many times. best to put a bead on, assembly lightly prior to tightening (to let the silicone 'skin'), then tighten.

So where do you get the "trap oxidizer replacement pipe" ?

For the 1987 300D Turbo, the trap catalyst was removed as part of a factory recall "campaign" and replaced by a "jumper" pipe and a small catalyst downstream of the turbo (under the car). The recall is IIRC still valid and is done at no cost to the owner regardless of miles on the car.

For the 1985 300D (W123) and 300SD (W126), the trap catalyst was not recalled. Mercedes probably decided those cars were too old to bother. There is a forum member who makes bypass pipes you can install yourself; sorry I do not remember who it is.

Jeremy

Trap Replacement
 

That Would be Monstercraftsman.net

heh, yeah sixto, that's a 617 in your pic. the exhaust manifold has mated runners.

(Quote)-- (For the 1985 300D (W123) and 300SD (W126), the trap catalyst was not recalled. Mercedes probably decided those cars were too old to bother)


When i bought the 85 back in 97, it didn`t have any power. the Indy shop I took it to, contacted the dealer. they ran a check on the Vin #, and the trap was due for replacement under the emissions system warranty. the thing was to be changed every 30K miles, and it had 50K on it. MB paid for the work.

I don`t know if there was a recall or not for the 85.

Charlie

Correct, Charlie, the 1985 300D and 300SD (California versions) came from the factory with a "trap oxidizer" that was replaced every 30,000 miles as part of routine service and at no cost to the owner. This was a "quick fix" designed to get them past the EPA and Cal-DOT until they could come up with something better.

During the years that this process continued (and obviously some owners had the oxidizer replaced several times and others never got around to it), Mercedes developed the "trap catalyst," which was a permanent replacement for the "trap oxidizer." Once each car had a "trap cat" installed, Mercedes washed their corporate hands of it.

There must be a few cars out there somewhere still with the original trap oxidizer but I have never seen one. In any case, Mercedes never did a formal "recall" campaign like they did for the 1987 300D and 300SDL with the OM603 engine.

Jeremy

The 85 California emission 300SDs were part of the trap-ox service campaign. On the 85 they changed from a trap-ox to a Trap-Cat that flowed better. When I had mine done it made it feel like a whole new car.

If you have had regular service at the MB dealer since the campaign started they probably did it. If not you might still be able to get them to do it (since the car is 25 years old it no longer has to meet emissions). If you have applied for a mileage badge and haven't had it done you will get a letter from MB telling you that you can have it done.