I am in the process of clean extra parts for my 1984 300D to Hydro print them in Red Carbon Fiber pattern. When I removed the intake manifold from another car, it had thick junk inside I guess it is from the oil being sucked in from the cleaner. Anyway, there is a switch attached to the monifold, the hole on it was clogged from carbon build up. What is the switch for? I took a scribe and clean it out and sprayed brake cleaner to remove the junk, now it is clean. Thank you.

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1984 300D, 1972 LT1 Corvette, 2014 Artic White 3LT/Z51 C7, 2013 650i Convertible BMW, 1994 Kawasaki Vulcan, 1992 Yamaha Seca II and 1996 Dodge Ram 2500.

The oil in your manifold mixed with the soot from the EGR valve is what is causing the goo or tar like substance. The oil is not the problem, the EGR is.

On the rear of the Intake manifold is a Banjo bolt with a opaque plastic line going over to the drivers side to a Switch, (Switch over valve) then from the switch it goes to the ALDA on the Injection Pump. This line is a boost line, and as the Turbo increases in speed, adds more boost pressure to the ALDA which increases the fuel to the engine.

The boost PSI is around 9, the Switch on the top of the Intake manifold is a pressure switch. if boost gets too high, (say 15spi) the pressure closes the switch which send a signal to the Switch over valve which dumps the extra boost to a safe level. This is a engine protection device.

Blow the switch out with some car cleaner, and the banjo bolt on the rear of the IM should be clean also. if you lack boost, this bolt is plugged with the tar goo.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

The most likely source for oil in the intake is a leaky turbo seal.

The switch doesn't regulate boost, it regulates fueling. When turbo pressure rises above 1.1 bar, it switches off the boost switchover valve, which prevents the boost signal from reaching the Alda. This has the effect of reducing fueling.

Boost is regulated by the wastegate, which is pneumatically actuated by boost pressure above .9 bar on most older Benz's. Above that pressure, the wastegate dumps exhaust directly into the outlet pipe, bypassing the input turbine.