Pulled off the air filter housing and found it to be sitting on top of a metal box so the air goes through the filter, than the box, than the black rubber intake hose with the crank case vent and than into the turbo. looks similar to a mass air flow sensor/ stupid emissions controll part etc...

what is this box?
What was its intended function?
as all other egr/emmisions controls has ceased to function why should i not remove this and put a re-usable oil,cotton high flow air filter in place of the stock set up?

__________________
sold
1987 300 SDL 318K
126.125 (OM603.961) (722.321 trans) (head#14)
Born on date 11/07/1986
2.5" Flowmaster Exhaust
flex-a-lite dual electric cooling fan conversion

now have a 1985 toyota diesel pickup

I'd sure like to get rid of that box myself. I can't change the bulb on the Euro headlight on the right side because of that damn box. The entire headlight has to be removed in order to change the bulb.

I sure don't see what the function of it is for the SDL.

Should be able to change the headlight bulb with the box in place, I can....

Anyway, the box is the flow meter for the engine controls (idle speed control, air recirc, EGR) found on these engines. It measures the air flow to switch the air recirc on and off, and I guess the EGR as well.

The air recirc valve appears to increase milage a bit on the highway by reducing boost (and hence fuel use) when you don't need it. EGR is another story, most people want to disable it to prevent coked oil in the intake. However, my brother's SDL with 200,000 miles (on synthetic oil since about 80,000) didn't have any buildup when we changed the gasket on the crossover pipe a couple weeks ago, just a thin layer of soot in oil.

You should not put a K&N fliter on it because the paper one works better and is quieter.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Not possible to open the access door on the Depo's because it hits the steel box. The clearance is less than 1/2 inch; not enough to get the access door to release.

Brian,

You should clarify that you can't open the hatch for Euro headlights in a W126.

Sixto
95 S420
87 300SDL

The hatch has a tab near the bottom of the headlight. To open the hatch requires that the hatch unclip at the top and rotate on the tab, rearward, about 1 1/2 inches or so. After the hatch opens up to this amount, then the tab at the bottom will release the plastic catch and the hatch can be completely removed from the headlight.

The problem with the right side is that the hatch can only move rearward by 1/2 inch. This is insufficient to clear the plastic catch at the bottom so the door is not removable. This requires removal of the headlight to change the bulb.

Note that this is with the Depo's. Bosch may be different.

so the box controls the opening and closing of the EGR which is the same as the air recirc valve.

I dont think the opening and recirculation of exhaust gasses has much to do with increasing milage. at steady highway speeds boost pressure drops to about 3-4 psi with or without a workig egr system. touch the throttle and boost goes up.

My point in removing the box is to smooth the flow of air into the turbo intake.
there must be some resistance going through that box.

__________________
sold
1987 300 SDL 318K
126.125 (OM603.961) (722.321 trans) (head#14)
Born on date 11/07/1986
2.5" Flowmaster Exhaust
flex-a-lite dual electric cooling fan conversion

now have a 1985 toyota diesel pickup

on the Garret its a vac line to the front of the turbo, just pull and plug. Not sure where on the KKK, but similar.

It's not costing you a thing, and reduces turbo lag -- I'd personally leave it alone if the system holds vacuum.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

psfred your probably right I should just leave it alone. The egr is blocked that is the most important.

__________________
2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200