Thought I would share some wisdom regarding 1985 300D Turbo factory equipped with a trap oxidizer. The trap oxidizer is located on the exhaust side of the turbo and is there to improve emissions. (I think). The problem is the material used in the Trap Oxidizer is similar to steel wool, and seems to breakdown and come apart 30-50K miles. The result is metal particles going through the turbo. Ouch!

This happened to me with a whistling sound, then a box of marbles sound, resulting in a big loss of power. I still got home.
My mechanic told me I needed a new turbo assembly at a cost of $4000.00. I was completely prepared to donate the car out of my life until he told me there was a possibility...............

As it turns out, Mercedes has a campain/recall of the trap oxidizer. This entitles the owner to have the oxidizer replaced two times during the life of the car regardless of ownership. I ended up getting a whole new turbo and a redesigned catalist type oxidizer.

For free. At 185,000 miles. Go figure!

None-the-less Mercedes Benz stands behind thier products and I am very happy. Thought I would share this with you.

Jim Stevens
1985 300DT 406,401 miles

do all years of 300D's have them? I have an 84 turbo and I was wondering how you went about getting Mercedes to change it?

I was wondering about that because I didn't see anything like that under my hood. Trust me, I ran outside and looked. The last thing I want is to have my turbo seize durning my commute to work in the morning. Usually about 20 minutes at about 80-85 mph. Already had the radiator blow on me at that speed, didn't want any other headaches. TXBILL, thanks for the info.

406K, very nice! Keep up the good work!

I had an 85 300DT with 470K miles. Amazing cars!

I searched "trap oxidizer" and it looks like it may not apply to just 1985 cars. Check it out by clicking on "search"

Jim

I believe in '85 only California had them, that was the first year for the trap oxydizer. In '87 all 50 states got traps. They were supposed to be replaced (at no charge) by MBZ every 30,000 miles at the regular 30,000 service. Somewhere in the mid 90's MBZ came up with a retrofit catalyst (as opposed to oxydizer) that never needs to be replaced (presumably). The new oxydizer looks the same on the '85 but is noticeably smaller on the '87. In both cases they are located about 2 inches down the exhaust manifold right next to the engine. On the '85 they are especially easy to spot because cars with the trap have an entirely different air filter set up than the other 49 state cars. By the way, MBZ keeps a complete online record of all the trap changes and when they were made so if you own the car (they only release the info to the owner) your local service department can look up the trap history. You can bet it's accurate because it was free at a dealer but cost $500+ at an indy so if it was done it was done at the MBZ dealer. There are likely very few cars still running around with the old style oxydizer....although I recently saw one on Ebay.

__________________
LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold

Will the trap oxidizer cause any problem if your car had 26800 miles on it? I ask the dealer and they told me they won't change it until I get to 30000 miles.