Hi Brian, I missed the type of car here, but I gather it's a W124 or W126 with an OM603 engine. I've tinkered with those a little myself, and have a couple of comments. First, you need to test vacuum directly at the port on the pump - disconnect the hose that goes to the 4-way branch fitting. If there's zero vacuum from the pump, the pump is bad (or the port is blocked somehow). The pump isn't cheap, either. If the pump does NOT have 4 Torx-head screws in the front cover, it should be replaced on principle even if it is working OK.
Anyway, if there is a leak on any of the vacuum 'consumers', that can cause all the other vacuum operated items to not function. That would be the emissions junk (which can be disabled), the tranny (which will shift harshly with no vacuum), and the climate control vent flaps. The large port on the vac pump feeds both the power brake booster *and* the engine shutoff. If the engine won't shut off, it could be the diaphragm on the injection pump, a leak in the brake booster pipe, or (once again) a bad vacuum pump. It sounds like you have verified that the pump is bad, but first I'd want to disconnect both ports, plug the large one, and measure at the small one. A big leak on the main port could possibly cause no vacuum present at the small port. (?) Don't mess around with that idler pulley - the serpentine belt system is not something to screw with, it can cause the timing cover to fracture (read $$$$ to fix). If the belt isn't perfectly parallel at the tensioner/idler pulleys, REPLACE the idler lever. The idler puley only needs replacement if the bearing is bad. Only use an OE (Genuine Mercedes) belt shock - the eyelet bushings are different than the OEM (aftermarket) shocks. I'm sorry you had a bad experience with that shop. I remember Stefan's name from the previous (MBZ.org) list, I had forgotten he sold the car. Wasn't that a 350SDL...? Best regards, -- Dave M. Boise, ID 1994 E500 - 95kmi (Q-ship) 1987 300D - 261kmi (Sportline) > ------------------------------ > Date: Wed, 14 Dec 2005 22:37:38 -0500 > From: "Brian Smyla" <[EMAIL PROTECTED]> > Subject: [MBZ] Vacuum pump question answered, plus rant > > Thanks to all those that replied to my question about the vacuum pump port. > I had the engine replaced with a used one, and the shop that did the work > warranted the engine for 30 days. The day after I picked the car up, the > engine wouldn't stop. I took it back to have the problem resolved, and was > told the problem was in the vacuum transducers near the turbo. I took the > car back, then discovered that there wasn't any vacuum on the small port on > the pump. Also, the climate control had air coming from the defrost ports > only, and the shifting was very hard, as was mentioned in some of your > replies. > > I had a very bad experience with this engine replacement. The shop owner > claims to have many years experience working on MBZ products, but when I > picked the car up, the heat didn't work (mechanic said it was a problem with > my climate control), the starter engaged intermittently, the idler pulley > was chafing the back side of the belt, a turbo support bracket was missing, > and various bolts were missing here and there. I spent three hours checking > the climate control, only to finally figure out that the mechanic had left a > plug in the return water pipe where it connects to the heater hose that > comes off the monovalve. I returned the car for repair of the other > problems. They fixed the starter issue, installed the turbo bracket ( after > arguing with me on the phone for 5 minutes that the bracket didn't exist ), > told me the idler pulley wasn't part of what was warranted ( the idler > pulley was from the replacement engine, and I told him that since it wasn't > under warranty, I wanted my old one back ), and said the shutoff problem was > in the emission control transducers, which I know is BS, because there's no > vacuum on the port to start with. > > > > If anyone's interested, the shop is Chaney's Auto Service in Ringgold, VA. > I'm not going back. > > Oh, and he charged me $2000 for the replacement engine, labor to remove the > replacement engine from the donor vehicle, promised me a 10% cash discount > from the original quoted price, then added enough miscellaneous parts (motor > mounts, used starter, hoses, etc..) to make up the difference. Go figure. > And no, it's not worth going to court over. > > And to make matters worse, I bought the car from Stefan Schultze, who > assured me that the only thing wrong with it was bad hood hinges. Flew to > Indiana to pick it up, where he told me that the heater had been > intermittently working. Drove it back, then discovered it had a cracked > head. All 6 cylinders. Refused to reply to follow up emails asking for a > $1k concession. I know, my fault, caveat emptor and all that. > > Thanks for letting me vent. > > Brian Smyla >
