Buzzing sound and won't start. - PeachParts Mercedes-Benz Forum

tankowner · #1 06-25-2010, 10:12 PM

Hey all,

I've had the 240D torn all apart for quite some time replacing lots of stuff. I have had the tranny off and have replaced all the clutch components. Also had to replace the slave cylinder. I have tried to bleed the clutch by the RF brake caliper method and it seems as if it is working, but I don't know if I really have all the pressure I should have when I press the clutch pedal.

Anyway, I buttoned everything back up (also had the intake/exhaust manifolds off to replace gasket) and tried to fire it up - no dice. With the clutch pedal pushed in, I turn the key and just get a buzzing sound. It has been sitting for some time, but I put a charger on the battery and it says it is good (lights come on, etc.). What's the deal here?

Is this a clutch problem? If I haven't managed to bleed it entirely, and the clutch doesn't function, will that keep it from turning over and the buzzing I am hearing is the starter not being able to crank the engine? It's hard to tell where the buzzing is coming from. Any thoughts?

Diesel911 · #2 06-26-2010, 12:06 AM

If it is not in Gear the Engine should be able to turn over.

tankowner · #3 06-26-2010, 01:57 AM

Quote:

Originally Posted by Diesel911

If it is not in Gear the Engine should be able to turn over.

It's not in gear. I guess I was just thinking that if the slave wasn't working properly it wouldn't relieve the pressure plate, not allowing the engine to turn freely - maybe I am thinking about it all wrong though.

Why the buzzing and no cranking when I turn the key then, any ideas? Thanks.

Junkman · #4 06-26-2010, 08:49 AM

You really need to go through the test procedures to determine whether or not current is getting to the proper places. Fully charged battery is 12.6 measured across the posts. You should also have the same reading at the large terminal on the solenoid. There is a small (white?) wire on the solenoid that gets full battery voltage with key to start and closes the solenoid. Starter should spin the engine. There is a junction block on the passenger side frame under the hood that should be clean and can be used to start it. I don't know if these cars have a lock out switch on the clutch pedal as my SD is auto. Diesel Ram has one, 78 Datsun was built when driver was expected to know better than to start in gear. Much more detail is available here & via google.

tankowner · #5 06-26-2010, 12:12 PM

Quote:

Originally Posted by Junkman

You really need to go through the test procedures to determine whether or not current is getting to the proper places. Fully charged battery is 12.6 measured across the posts. You should also have the same reading at the large terminal on the solenoid. There is a small (white?) wire on the solenoid that gets full battery voltage with key to start and closes the solenoid. Starter should spin the engine. There is a junction block on the passenger side frame under the hood that should be clean and can be used to start it.

The battery is fully charged (verified with meter) and there was power to the starter. I couldn't locate the junction box you mentioned, so I decided to smack the solenoid with a hammer just for kicks. I don't know if it was that or something else, but I crawled in to give it another try and she turned over for me. The 240D lives again!!! I took it for a very short drive to test out the clutch and everything appears to be working well there - woo hoo! Now, on to the front suspension rebuild. Thanks guys.