BENZ AID - COMMON QUESTIONS AND ANSWERS

W126 350SD 1991 thrown belt

I'm not exactly sure what happened with my car but I've heard it described as a thrown belt, anyway it broke and ripped my power steering pump off and tore off the belt tensioner pulley.
I'm in the process of putting things back together and noticed that I need a new AC compressor. Should I attempt to replace it myself if I have no prior experience with AC and don't want to buy a bunch of expensive tools?
Also, how do you get the high pressure hose off of the power steering pump where it connects to the pump reservoir?

Chassis Model Number

W126

Forums

Diesel Engine Specific Aid

1985 300 SD turbo diesel Auxillary Fan Not Working

n/a Auxillary fan for air conditioning system will not energize. Car overheats when using air conditioning in traffic. Fan is new, fuse C has been checked. climate control is newly rebuilt. Air is cold fan is working on all speeds. Read somewhere that the auxillary fan is controlled by temperature switch at drier. Is this correct? How do I go about diagnosing the problem. Thanks

Chassis Model Number

W126

Forums

Diesel Engine Specific Aid

1976 300D ho-hum fuel mileage

Car is getting 20-23 MPG and can not seem to get much improvement. This was the mileage when I started, and have since adjusted the valves (nice wrenches, Kent!), changed the fuel filters, replaced all fuel lines (they were hard and looked leakish), installed Monarch nozzles set to 1620PSI (great kit!). After all of that, it runs like a dream with not much smoke, but still the same ho-hum mileage.

I tested an injector before I cleaned, re-sealed and installed the Monarchs. It popped at about 1400 and shot a straight jet. After cleaning, sealing, shimming and installing the monarchs, they all pop at 1620 and shoot a nice smokey atomized pattern. I was sure this would do it, but there was virtually no change other than in smoothness.

Chassis Model Number

W115

Forums

Diesel Engine Specific Aid

Missing Vac Switch in ALDA line.

I have a 1979 W116 300SD, chassis has 334k miles and rebuilt engine around 100k. When I purchased the car, the vac switch that attaches to the firewall that helps control the ALDA valve is missing. I have read various articles describing the pro and cons. I am afraid to 'step' on it in fear of what may happen. Should I replace the switch? Or what would you do?

Chassis Model Number

W116

Forums

Diesel Engine Specific Aid

84 380Sl engine stumbles

n/a 1984 380SL- bought car with seized engine, replaced with 60K engine from 85 380SE, new rebuilt trans from MB. Installed new fuel pump, filter, plugs, wires, cap, rotor. Engine starts great, rev's great, put in gear and accelerate slowly,and every thing seems ok. Accelerate too fast and engine will stall or start missing. It will get up to speed and seem to run fine, although it feels like it has a slight miss. Come to a hill and it starts missing very noticably but will maintian speed. Car will surge when on cruise control, I assume becouse of miss.

Chassis Model Number

R107

Forums

Gas Engine Specific Aid

1983 300SD vacuum diagnosis

Hi, All,

I have isolated a vacuum problem to the red/green plastic line that services (I think) interior switches and servos: with this red/green line attached to its fitting on the vac system, system pressure drops from 45m/g to 15m/g or less with the engine running. When the car is turned OFF, the line holds vacuum (??); when the car is ON, its as if it's open on the other end, bleeding off vacuum (brakes go hard after 2-3 pumps; engine won't shut off if at idle awhile).

Does this behavior suggest a specific component that I should go after?

Thanks in advance!

Chassis Model Number

W126

Forums

Diesel Engine Specific Aid

1985 w126 300sd cental locking system failure to lock

I have posted this question on a few other Mercedes Forums with no assistance. So...I have paid the 30 bucks for hopefully some light to be shed.

I have a strange problem with my central locks.

The problem I am having is that locking any controlling (driver passenger trunk)lock will cause all locks to unlock but it is impossible to lock the doors. I obviously have no leaks.

What I have so far.
I have run the pump on the bench and if I ground any of the 3 pins the pump pulls untill the vac switch makes. Then if I apply 12v to a pin the pump pushes until the press switch makes. This seems to make sense. Keep in mind I did not test the pump with a constant 12v on any pins and I will try that later today.

I also tested the wiring in the car and all is correct.

Chassis Model Number

W126

Forums

Body and Interior Specific Aid

1983 300d white smoke, no power

need help. i have a 1983 300d 150k on the clock. hard start when cold, heavy white smoke through out operating temperture, no power. compression at 330psi all cylinders.check diesel fuel, ok. replaced all fuel filters and in tank screen. replaced all glow plugs,relay. replaced all injector nozzles. replaced all fuel hoses and plastic lines. problem still exist.performed timing chain stretch. Found 6 degrees after tdc. any ideas?

Chassis Model Number

W123

Forums

Diesel Engine Specific Aid

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