1985 300D plugged turbo - PeachParts Mercedes-Benz Forum

kaleope · #1 11-27-2010, 09:26 AM

okay,
the car just would not go, not shifting and tons of smoke coming out of exhaust, it would go to 32 rpm and not shift, then the smoke. MEchanic said the turbo was not working. It took me almost 2 months to find another turbo. When we removed the old turbo, a ceramic block was jammed into one of the passages, of course the car was choking ! I bought it like this, would anyone know why someone would block one of the passages in the turbo ? Of course now the car runs fine with the other turbo but maybe I did not need it to start with, it is very strange. Any input appreciated to cure the curiosity.

vstech · #2 11-27-2010, 09:38 AM

pics?

vstech · #3 11-27-2010, 09:39 AM

very unlikely a mechanic checking the car and finding bad turbo would miss a block in the tubes. is it possible he put it in there?

mach0415 · #4 11-27-2010, 11:06 AM

i am not too familiar with this setup on 300ds, but is this a possible trap oxidizer failure causing the the turbo to k/o?

Jeremy5848 · #5 11-27-2010, 12:27 PM

Was this ceramic block jammed in the exhaust side of the turbo or the air intake side? An exhaust-side problem could come from a disintegrating trap cat, assuming the car was built for the California market and had one to begin with.

mach0415 · #6 11-27-2010, 04:26 PM

Quote:

Originally Posted by Jeremy5848

Was this ceramic block jammed in the exhaust side of the turbo or the air intake side? An exhaust-side problem could come from a disintegrating trap cat, assuming the car was built for the California market and had one to begin with.

Ditto. This was the first thing that came to my mind.

kaleope · #7 12-03-2010, 02:12 PM

thank you everyone
let me state that I do not know anything about these cars (diesel) I had classics back when but gasoline. Mt son (16) wanted this car as a project and lost interest, as I got used to driving it I really like it and don't want to part with it though I have a lot to learn. I did more research from everyones input and I have not had time to take pictures to show you yet BUT from the info given I think that we can say that the turbo fail was caused by the trap oxidizer because what I found is similar to what other people have suffered with.... porcelain like honeycomb grid pieces inside the turbo....
here is one example
http://newsgroups.derkeiler.com/Archive/Alt/alt.auto.mercedes/2005-09/msg00260.html
I misplaced the other article online right now but I will find it so we all benefit,
thank you again everyone

Diesel911 · #8 12-03-2010, 02:53 PM

I think I have an idea why the Ceramic Block was there and why it was not shifting.

There are Turbo Chargers (VNT Turbos?) that have a variable inlet Valve (Nozzle) so that at low speeds the part of the flow to the Turbo is blocked off but the blockage increases the velocity of the Exhaust Gasses (like a water Hose Nozzle) so you get boost at lower speeds.
As Engine Speed Increases the the Valve opens up and the Turbo functions as it would normally.
So I think some one put the Ceramic Block in Thinking that they could get better performance but instead what they did was cause the Turbo to over boost. The over boost was causing the Part that I cannot remember the name of (over boost protection relay?) that protects the transmission when there is an over boost to effect the shifting.

layback40 · #9 12-03-2010, 08:01 PM

I thought they had a recall; to get rid of the trap ox & put one in the exhaust system under the car. If the trap ox is still there, get rid of it.

The VNT have movable metal blades in the housing that do as has been suggested, no ceramics.

Diesel911 · #10 12-03-2010, 11:04 PM

Quote:

Originally Posted by layback40

I thought they had a recall; to get rid of the trap ox & put one in the exhaust system under the car. If the trap ox is still there, get rid of it.

The VNT have movable metal blades in the housing that do as has been suggested, no ceramics.

I was not suggesting that the Turbo came with the ceramic block; I was suggesting that someone put the ceramic block in the Turbo to mimic what a VNT does.

The problem is that the person only 1/2 understood how a VNT works and you can see what it was doing to the original Turbo/Engine.

my123ca · #11 12-04-2010, 10:31 AM

Quote:

Originally Posted by kaleope

okay,
the car just would not go, not shifting and tons of smoke coming out of exhaust, it would go to 32 rpm and not shift, then the smoke. MEchanic said the turbo was not working. It took me almost 2 months to find another turbo. When we removed the old turbo, a ceramic block was jammed into one of the passages, of course the car was choking ! I bought it like this, would anyone know why someone would block one of the passages in the turbo ? Of course now the car runs fine with the other turbo but maybe I did not need it to start with, it is very strange. Any input appreciated to cure the curiosity.

You need to replace the trap oxidizer as it will destroy your replacement turbo too. If you still have the original trap oxidizer, mercedes could have replaced that for free, including a new turbo. You can convert to the federal version to avoid the trap or you can replace the trap with a straight pipe. I wont trust that trap anymore as it is showing signs of disintegration already.

69shovlhed · #12 12-04-2010, 06:17 PM

the trap oxidizer recall is in effect forever. take it to the dealer and get it fixed asap for free. i did a few conversions under the recall on cars w/ over 100k on them. recalls do not expire. and yes that block was a piece of the trap.

kaleope · #13 12-27-2010, 10:30 PM

first of all, thank you everyone !
I know have a great running car thanks to this sight and to monstercraftsman. The trap ox definitely disintegrated and let pieces go into the turbo. There is a recall or a campaign for this by mercedes but when I drove near the dealer I got a gut feeling, I just did not want my car in there. With a little poking around on the internet, I found monstercraftsman had a bypass test pipe. I purchased that plus an egr valve blocking plate and worked with my mechanic to get it installed. Only thing was some of the bolts from the trap ox would not come out so we had to rethread, other than that it worked out GREAT and I wanted everyone to know. Jon was great at monstercraft too ! Always answered the phone and helped me out. If you think you have this problem, just look him up and call, he'll help you out. I really think the car was made for autobahn, when you get to the right speedlimit in NY (60) it really wants to take off ! So my only problem now is we have 18 inches of snow in NY and the Benz will not move at all in the snow

PS...I have the california model..

vstech · #14 12-28-2010, 07:57 AM

... you paid money to repair a factory defect that has a free replacement never to expire warranty? um... ok.
what was at the dealer that made you not wanna go there?
I'm pretty sure anybody else with this problem is going to get the new exhaust manifold, turbo and free labor that the dealer would provide...
just my .02...

Beastie · #15 12-28-2010, 08:06 AM

How do I know if my car has the trap oxidizer ? Is this only on the Cali cars ?