I can't find where this sends the "signal". Mine was not connected when I bought the engine.

Any input?

Roy

Should we guess which car and year you are asking about?

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

Geez, I'm sorry. It's been a long weekend.

It's a 1983 300TD

I'm guessing your refferring to a turbo charged 5 cylinder. If it's the switch on the rear of the intake manifold, it's the over boost switch. It cuts out the pressure signal to the injector pump when manifold pressure exceeds approx 20psi. If you look, you'll find a small solenoid on the fire wall just behind the pump. The switch activates that solenoid to "dump" the pressure, which in turns reduces the fuel delivered.

Dieselnut got it, it is a switch for the overboost "switchover" valve. It does not dump pressure though, just blocks the pressure signal to the ALDA, thus limiting the fuel available.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

In theory you could add to the setup to dump pressure, by installing some sort of solenoid valve on the waste gate hose's path, then it'd open and dump the pressure, thus no boost....

I suppose you could also add a valve with a similar device to the intake itself....either location would work I suppose....so long as it eliminated boost/pressure.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I removed my switchover valves.



inb4 "your gonna hurt your engine"

__________________
1981 300SD 512k OM603

I meant it dumps the pressure going to the ALDA unit, not the pressure from the turbo, my bad. lol. Mine's been disconnected for the last 75K along with my EGR valve. Runs better!!!

Pressure regulated BOV?

__________________
Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

Its not made to be switched that often or quickly. If an intake switch sees contact once every 20 years, its probably above the average count.

On most of the 617's I've owned, it has been bypassed.

__________________
83 SD

84 CD

Its still active on all of ours.....not on the one we got with a blown engine though, I wonder why.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

The switchover vavle does, in fact, "dump" (vent) the pressure between the valve and the ALDA. In simple terms, pressure is blocked on the upstream side and vented on the downstream side of the switchover valve. Otherwise, residual pressure would prevent the overboost protection system from functioning as intended.

Naturally.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

the pressure swtich is a failsafe if the dump gate fails to open properly