Was reading over the itemized bill from the mechanic at the mercedes dealer who did and awesome job fixing my tranny shift problems. I did not get a chance to speak with him personally, since he had left for the day.

It says - and I need help to know what he may have done - he tested vac controls, replaced 2-3way valve on valve cover, adjust accel. and trans linkages and cables, adjust modulator pressure and valve o injection pump, test boost control circuit, clean lines and by pass restricted switch-over valve C3.0P
Wonder what he bypassed? Any guesses?

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1982 300SD Light Blue
2002 Honda Accord SE
1974 Toro Wheel Horse Tractor
2000 Toyota Tundra Pickup

Not sure exactly what C3.0P is but look around in front of the brake master cylinder area. You should see a solenoid valve with a couple pressure lines attached. If the lines are not attached then this is what he bypassed.

Not exactly sure this is what it is referring to though.

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Jim

Maybe he's talking about the "overboost protection" valve.

If the intake manifold pressure rises too high (e.g., failure of wastegate to open), then this valve disconnects the "pressure signal" going from the intake manifold to the ALDA on the injection pump. The IP then no longer increases fuel delivery as a function of intake pressure, dramatically reducing available horsepower (and preventing a meltdown).

A search of the forum would turn up more and better descriptions than I've given.

Edit: this is the same valve Engatwork described.

He may have meant to say "Bypass Restrictor in switch-over valve"

Vacuum restrictors, (I just bought one yesterday cost $3.00) are basically in-line little plastic tubes that hook-up into a rubber vacuum line. They are smaller in diameter than the original line. This effectively reduces the overall dimension of that line, and consequently decreases the available vacuum. Some of these restrictors also have a little filter inside.

I assume that yours was either partially or totally plugged, and that he did not have another one in stock, or that he removed it because he needed to increase the amount of vacuum in that line for some reason.

Phil

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'95 E300 Diesel, 264,000 Miles. [Sold it]

A switchover valve is not the color coded orifice that you all are refering too.
I can't remember which one is technicaly called a switchover valve by MB, someone with a FSM and time look it up. I'm guessing he disabled the EGR.

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

This is what I thought of as soon as I saw "switchover valve"

I would find out what he actually did and get it corrected right away. You don't want to leave it unprotected like that for too long.

Danny

My factory manual calls it the switchover valve, it's *probibly* not a problem, but I'd fix that, it's there for a reason. I'm sure I have some at work Will..

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

Should look somewhat like this.
It's screwed to the firewall behind
the brake booster.


Louis.

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