Benz Disaster
 

Please Help. Car is a 92 300E 4matic I was driving home from work. Stopped to get the mail. Got back in the car and decided to to see if the car still had some snot. So I nailed her, (dirt road) engine redlined(6800) and stalled at the top of the hill. It will crank but not start. Car has had some tranny problems won't shift out of first below 3000, and always shifts a little slow. Any help would be appreciated as this is the parents car, and they are not impressed. Thanks in advance

Did it stall as it was redlining?

I've been there kid, I'm sure we all have, and I sure don't envy you.

I imagine it has a rev limiter which will prevent damage to the main mechaincal parts of the motor. It may have gone a bit too far and stopped the car from running (kindof a young person limiter:P)

I doubt too much damage is done.

Maybe a relay or a loose wire.

Tom W

it died as it was redlining I believe, if not, shortly after.

Ya, young and foolish.

How can I test the fuel pump, and where is it located? Please be external of the fuel tank...

it is....

good news is that you're about to learn how to fix a car.

Read up here a lot and explain to the parents that you've got a few dozen friends to help.

If you survive the discussion, the car might too.

-CTH

I'm pretty good at fixing old stuff, I have a pair of spitfires. It's just all this electronics stuff that is bothersome. I prefer my mechanical Cam driven fuel pump lol here's my blog

When this happened to me in my youth it was due to points.

I'd check spark, and if getting none look at teh CPS and then coils.

If you are lucky, the rotor fell apart. If you are not lucky, the timing chain broke.

Take off the oil filler cap and watch the camshaft while someone cranks. If it doesn't turn, it's valve job time. If it does, remove the distributor cap and see if the rotor is in bits. If so, replace it and you will be OK.

DO NOT redline an engine in unknown condition unless you don't care if it's gonna survive -- a worn timing chain will let go for sure, and the M103 doesn't have a really robust chain.

If you have an M104 (dual overhead cam), it won't be the rotor.

There are other possibilities -- bad crank position sensor, dead ignition computer, fried coil, dead fuel pump (see if it runs when you crank it), and more, but if it died at high rpm, don't expect it to be cheap.

When you get it running, adjust the kickdown cable and fix the vacuum leak at the modulator on the tranny or the intake manifold.

Peter

Thank You Peter. I definately learned a lesson

Rotor isn't spinning. There goes the timing chain. I'm guessing that it's an interference engine and some of the valves are cooked.

On some cars there is a rolled pin that holds the rotor gear on the shaft. This can shear, putting you out of business. I did it once on my Saab and was not doing anything unusual.

Pull the distributor and check to see if the rotor turns when you turn the gear.

Tom W

I don't think would be your timing chain if you can still crank the car. I imagine it would make some pretty bad noises if the valves and pistons were hitting each other.

I took off the valve cover and the timing chain is definately gone. I can see it all bound up under the gear on the cam.

I too am wondering why it still cranks so smooth. There was no big noise, just the usual kick from the slow shift on the tranny. No big clicking, or crunching. None of the valves are fully open. I think I may be lucky, probably speaking too soon.

You may not hear any noise when you crank (like pistons hitting valves) because all the noise was made when the timing chain broke @ redline and the valves are now "modified."

Ya, but I mean I didn't hear anything when it broke. Any tips or tricks to doing the timing chain. My plan of attack was to pull the head off, and check what's what. replace valves and pistons if I have to, then re assemble, new chain. Never done this on anything this big or complex. Any tips would be appreciated.

found the leak in the vacuum system

No tips except to say that reving a mb motor to the redline once shouldn't break anything. It was ready to go anyway.

A benz is built to run flat out on the autobahn for hours on end.

Tom W

Might be cheaper to find a good used engine from SilverStar Recycling or Potomac German Auto. I've seen M103's as low as $500 for a short-block.

:-) neil

That was going to be my suggestion..... heck it might even be cheaper to just find another W124, pull the engine and have a parts car.

used car for under 1,000$ is the way to go. They're out there, especially in NY.
Driving it north and then parting it out should be easy enough.

-CTH