Underneath intake manifold.. - PeachParts Mercedes-Benz Forum

Thingymagigercarpart · #1 10-12-2016, 06:30 PM

I replaced fuel orings on a om606 I just got and when I got the intake mfd off I noticed 3 things right off the back that were problems to me but two of them I didn't understand 1 is a terminal that is loose and 2 it looks like two vacuum lines that lead straight up to nowhere,
Any insight is appreciated.

jay_bob · #2 10-12-2016, 06:47 PM

What year is your car?

Thingymagigercarpart · #3 10-12-2016, 08:25 PM

1995

Thingymagigercarpart · #4 10-12-2016, 08:27 PM

I found the were the lines go to
Just trying to figure out where the terminal goes,

jay_bob · #5 10-12-2016, 08:34 PM

There is an electromagnetic valve under the manifold that switches the vacuum lines. This system changes the geometry of the intake under various engine load conditions.

Thingymagigercarpart · #6 10-12-2016, 08:37 PM

The one that is connected in a series? If so they are connected.

jay_bob · #7 10-12-2016, 08:59 PM

You do have the valve hooked up it appears. There are two valves in one package so there are two sets of wires.

I can't tell where that other connector goes. I would try messaging Jeremy5848, I know he has one of these cars.

Jeremy5848 · #8 10-12-2016, 10:26 PM

Quote:

Originally Posted by jay_bob

You do have the valve hooked up it appears. There are two valves in one package so there are two sets of wires.

I can't tell where that other connector goes. I would try messaging Jeremy5848, I know he has one of these cars.

You rang?

I believe that's an extra, unused connector. I haven't been under my intake manifold for some years but have a vague memory of sn unused connector. There are several other '95 E300D owners on this list; perhaps one of them will have additional information.

By the way, does the monovalve in your car leak (next to the battery, controls the flow of hot coolant to the heater core)? Just curious, many do, I'd like to add yours to my database, leak or not.

Jeremy

Thingymagigercarpart · #9 10-12-2016, 11:58 PM

Not a drop.

Thingymagigercarpart · #10 10-13-2016, 12:03 AM

I actually looked inside the terms and decided that as well, there was 0 scoring on the inside. Just zip tied to the wire harness.

Thingymagigercarpart · #11 10-13-2016, 12:08 AM

I appreciate the info!.

benedict · #12 10-13-2016, 05:29 AM

Yes, Jeremy is right, unused.

It is for a 'rack position sensor' which is for the later .912/962's. The sensor is usually fitted on top of the injection pump next to the shut off valve. It looks like a 'blank plate' approx 20-25mm wide from memory.

Jeremy5848 · #13 10-13-2016, 12:18 PM

Quote:

Originally Posted by Thingymagigercarpart

Not a drop.

You are fortunate—many of these particular monovalves leak (unique to the '95 E300D except for a very few, very late production 300D2.5's). Replacements are $800 and have the same problem. Mine was replaced three times, Mercedes finally refunded my money and I glue-repaired the original. It has lasted three years so far.

Jeremy

Thingymagigercarpart · #14 10-14-2016, 12:17 AM

Any particular failure I should be weary of?

Jeremy5848 · #15 10-14-2016, 11:51 AM

Quote:

Originally Posted by Thingymagigercarpart

Any particular failure I should be weary of?

The leak from a cracked monovalve isn't severe, more of a nuisance. The leaking coolant ends up down below the battery tray where there is (should be) a drain hole, so the coolant ends up on the garage floor. Should the drain hole be plugged, I suppose the coolant might cause rust if left untended. The amount of leaked coolant usually means you have to top up the expansion tank every few weeks or months.

If your monovalve isn't leaking, you're lucky. Buy a lottery ticket and don't worry about the monovalve.

I've also seen cracked monovalves that don't leak. For more details, see my thread "1995 E300D Monovalve Problem" in this forum at the following link:

1995 E300D Monovalve Problem

My monovalve was repaired with a $20 kit from an auto parts store, the kind that promises an instant repair for your leaking radiator or fuel tank or whatever. If I had done that in 2013 instead of buying a new monovalve ($500, today $800), we wouldn't be having this conversation!

Jeremy