I can't post a picture at the moment but I can give the part number and a brief discription.

Part Number: 001 540 7197

You can hear this thing ticking when you accelerate. It has three vacuum connections and one electrical connection. It mounts just in front of and below the coolant recovery tank. It sounds like a lifter ticking away. It is annoying!

Also, My tachometer is going haywire. It is working backwards at times. It seems to stick around 1,000 RPM's and then after it sits there for a while it works but I don't believe it's accurate. I have no idea where to begin on it. I have searched the archives but I am still unsure of where to begin. I HATE auto electrical stuff!

Thanks for any help you can give.

Kevin

I wonder if you are thinking about what I'm talking about here: http://www.peachparts.com/shopforum/diesel-discussion/87644-part-identification-post573523.html#post573523

__________________
1983 240D
www.againsttcpa.com
www.hydrogenaudio.org
www.ntfs.org

I hope it worked!

I do not see any thing like that on my '84 SD, sorry. I see in my CD manual that there were changes in the glowplug system starting in '85. I ran a parts no. search in the Fastlane and it did not find that part number.

__________________
1984 300SD 326,997 miles and counting . . . No wait, my odometer is still dead

It is an EGR system module. It costs $83.00 from my indy parts department. Ouch!

Kevin

Oilslick--is that a Califonnia spec. car? I find that valve on my CD under Calif. spec. cars but not Fed. spec. cars.

__________________
1984 300SD 326,997 miles and counting . . . No wait, my odometer is still dead

I dunno? I just bought it!



Kevin

If it's an '85 and originally from California (or as Arnold pronounces it.."Kale e four nee a") it should have a trap oxidizer or catalyst. Look for a metal, coffee can sized "lump" in the exhaust just downsteam from the turbo. If you see one it's a Left Coast car.

__________________
LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold

Wait a minute...unless they used the same valve for two different jobs, I've got an identical valve sitting right next to me (except the p/n is 001 540 7097). The lower vacuum connection attaches to a plastic hose that goes to the intake manifold, and the upper side conenction goes to a plastic hose that goes to the ALDA on the injector pump. The top one just vents to thin air (on mine, there's a plastic cap that's not airtight, but would keep bugs or too much dirt from getting in). The electrical connection goes to a sensor on the intake manifold that senses boost pressure. When the boost is low enough to not trigger the sensor, the valve lets the boost pressure go through to th eALDA so that the pump can add extra fuel proportionate to the boost level. When the boost gets high enough to trigger the sensor, the valve then sends the signal out the cap and into thin air, basically cutting off the extra fuel flow and making the boost level go down.

Unfortunately, mine's dead, so I get to drive the car like an old lady until I can get my hands on a boost gauge...

Again, maybe on the 126 (or on CA models), they used a second valve like this for something else, but that's a possible explanation for it...althuogh, on the 123, the valve is mounted on the firewall near the brake booster.

Just my $.02...hope it may help a bit...good luck!

__________________
2001 VW Jetta TDI, 5 speed, daily driver
1991 Ford F-350, work in progress
1984 Ford F-250 4x4, 6.9l turbo diesel, 5 speed manual
Previous oilburners: 1980 IH Scout, 1984 E-350, 1985 M-B 300D, 1979 M-B 300SD, 1983 M-B 300D
Spark-free since 1999

On the 1984 and 1985 California Spec cars that particular valve is what the tachometer is driven off of. Trust me, I found this out after getting a Tach for my 240D out of a 1984 300D and finding out looking through the Mercedes wiring diagrams that it won't work

__________________
Nick
*****
2002 Sprinter 2500 140" High Roof :

There are more than one of these under the hood of my car. They are just an electro-mechanical device that can be used for several things. Including what the Warden describes.
Irg, you cannot tell a CA car by that alone. From what I have seen the trap ox and the catalyst look identical.

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

Maybe this solenoid is causing my tachometer problem. I have an almost identical solenoid over near the brake booster. It has a line going to the banjo bolt and one coming off the ALDA. ALDA is a new "monkey" for me. This is my first turbo.

Kevin

Vwbuge,
You're right, on the 1985 cars they look excatly the same. The thing is that all Mercedes diesels sold in California in 1985 (and a couple of other Western states) has one or the other while the federal cars had neither. It is very rare that the trap has been completely removed, and even then the whole intake setup is usually different than a federal car. If it's an '85 and you see the "can", regardless of which type, it's a California emissions car. By the way, that is NOT true for the later cars where the retrofit catalyst looks quite different from the original oxidyzer.

LRG

__________________
LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold

I am not saying that it is NOT a CA car but there is no trap ox or catylyst either. THe intake and manifold look normal.

Kevin

the "relay" near the brake booster isnt a relay, it is the boost
overload protection valve.

your tach most likely has a sensor and a sending unit on and
in front of the harmonic balancer.
relays are just big switches, activated by smallwires/small
charges; putting out larger charges through larger wires. 12v
current loses its forse over distances, so you keep the heavy
current runs as short as possible.

i thought most trap oxidizers in california had been removed
via recall. they looked like a roll of joined metal balls at the
exhaust ports.

don "the electrical idiot"