Clicking/Ticking On Acceleration, '83 240D - PeachParts Mercedes-Benz Forum

jkoebel · #1 11-26-2007, 01:26 PM

I'm a bit concerned about my '83 240D, it's developed a clicking/ticking noise in the last few weeks.

I can't/can only just barely hear it while idling or maintaining a constant speed below ~45 mph. Above that, or while accelerating, it gets louder when given more throttle.

I've had my drive shaft flex discs replaced recently so I know it's not that (I searched before I posted this question) but have seen mention of things like, vacuum pump, oil pump, timing chain, etc.

I can't generally hear it when the car is parked/stopped, even when I rev, so I'm not sure really how to begin diagnosing. Any pointers?

EDIT:

I went downstairs and checked the oil. I added a quart and a half less than a week ago. There wasn't even a spec of oil on the dipstick. I added almost 3 quarts, and it's now in the middle of the "okay" range. It's never consumed oil like this before -- in the interval between when I bought it and when I did the first oil change, I had to add maybe 1 quart total.

There are no oil spots/drips under the car at all.

Only thing I've done differently is, I didn't add Power Service to my last tank. So, basically, nothing different at all. I'm very worried, now.

Does anyone know where I can order those clone 616 engines that have more HP than the originals do? If its something serious, I'd rather do that. I think they're Tempo?

dieseldan44 · #2 11-26-2007, 01:44 PM

I have the same sound. Im in the process of compiling data to post here.

My clicking/ticking is louder in the car than it is outside of it. Its distinct inside the cabin. I just got an automotive stethoscope yesterday and it will prove very useful. In a pinch, try listening with a long screwdriver with the plastic end against your ear

First - listen to the vacuum pump and timing chain to rule them out. Then listen to all of the injectors. I have done this and I can hear that my sound is not coming from these places, it seems like its coming from the rear of the engine towards the back or even the torque converter.

Im interested to see what other folks chip in with. Try listening for the things I mentioned earlier and report back...

dd

jkoebel · #3 11-26-2007, 01:48 PM

Yeah, I can't even hear my sound from outside the car really. It does sound like it's "back" in the engine, kind of low-down, like about the level of the shifter or CCU towards the center. I can't seem to localize it any further.

Will try listening and get back.

dieseldan44 · #4 11-26-2007, 01:51 PM

Quote:

Originally Posted by jkoebel

Yeah, I can't even hear my sound from outside the car really. It does sound like it's "back" in the engine, kind of low-down, like about the level of the shifter or CCU towards the center. I can't seem to localize it any further.

Will try listening and get back.

Try putting it up on ramps and getting under there to listen up-close-and personal. Try the bottom of the oil pan, torque converter, manifolds, anything you can get to.

dd

jkoebel · #5 11-26-2007, 03:38 PM

This may mean its totally not the engine at all:

Revving in park or neutral, there's no noise at all. Nothing. Even if I rev to the point where the engine sound changes to something I've never heard before and am afraid to press the throttle any further.

Neither, in Reverse. Only in drive going forward.

Transmission or TC, then?

Scott98 · #6 11-26-2007, 03:48 PM

I wouldn't worry about the oil problem - yet. See if it does it again over the next 3,000 miles. As far as your ticking goes, you might just have to crawl under the car and check every bolt/nut on your drivetrain to help narrow down the problem. Shake your driveshaft hard too and make sure your center support shaft bearing isn't bad.

Scott

Skippy · #7 11-26-2007, 06:38 PM

Exhaust leak?

turbobenz · #8 11-26-2007, 06:42 PM

I had a ticking in my 300d turbo, sount like it was from the back of the engine or transmission, ended up being a 50 cent shifter bushing. Yea, it did happen on acceleration and cruising speed. When they get old they crack and fall off. If its not their when you shift the selector youll feel its loose and sloppy, but with the bushing its tight and falls right into where you shift it without play at all and doesnt make a loud metal clanking noise.

dieseldan44 · #9 11-26-2007, 11:01 PM

Quote:

Originally Posted by turbobenz

I had a ticking in my 300d turbo, sount like it was from the back of the engine or transmission, ended up being a 50 cent shifter bushing. Yea, it did happen on acceleration and cruising speed. When they get old they crack and fall off. If its not their when you shift the selector youll feel its loose and sloppy, but with the bushing its tight and falls right into where you shift it without play at all and doesnt make a loud metal clanking noise.

Thats good to know!

I used the stethoscope again tonight and I have found a heat shield that seems to be making at east some of the noise, if not all of it. No spot on the engine or transmission itself exhibited any abnormal noise (other than sewing machine :-) ) Ill have to mess with it and then see what happens.

jkoebel - do you have a 4 speed or auto transmission?

easy_asW123 · #10 11-27-2007, 12:26 AM

Transmission shift bushings? My 82 300D had the exact problem except it was semi-distinctly heard from the shifter area. Maybe check that out?

jkoebel · #11 11-27-2007, 08:58 AM

Quote:

Originally Posted by dieseldan44

Thats good to know!

I used the stethoscope again tonight and I have found a heat shield that seems to be making at east some of the noise, if not all of it. No spot on the engine or transmission itself exhibited any abnormal noise (other than sewing machine :-) ) Ill have to mess with it and then see what happens.

jkoebel - do you have a 4 speed or auto transmission?

Auto tranny.

Cervan · #12 11-27-2007, 09:21 AM

Quote:

Originally Posted by jkoebel

This may mean its totally not the engine at all:

Revving in park or neutral, there's no noise at all. Nothing. Even if I rev to the point where the engine sound changes to something I've never heard before and am afraid to press the throttle any further.

Neither, in Reverse. Only in drive going forward.

Transmission or TC, then?

Not quite, i had a 616 engine that ticked like crazy it would drop a cylinder at idle and then come back at about 2k rpm and it ticked the loudest when under Load.I thought it was the drivetrain turns out, that when i pulled the head one cylinder had extreme carbon build up and the rest of the cyilnders were fine. It was one injector that was nailing at high speeds, i would suggest you replace your injectors and as for the oil consumption get a compression check while the injectors are out, if one cylinder is off the charts in compression you have oil leaking past the rings also check for blow-by thats usually a good tell tale sign. Maybie it could be valve stem seals very very easy job and really does make a diffrence. of course allways look for a massive leak on the ground, thats usually where it all goes if you using that much oil you can usually see the nice blue smoke from the tailpipe by then.

dieseldan44 · #13 11-27-2007, 11:27 AM

There have been a lot of great suggestions on this thread...

jkoebel - driving to work i noted the ticking is very light, almost leaf caught in a fan light. As I said I went all aroun dht eblock last night and couldnt hear anything coming from the block itself. I still think its that piece of metal that acts as a heat shield at the back of the turbo. In the cabin the sound is certainly coming through the passenger footwell more than the drivers.

Can you describe your sound more? Is it coming from one spot in particular? Is it a deeper metal-on-metal tick or a raspy chugging sound etc?

dd

dieseldan44 · #14 11-27-2007, 11:30 AM

Quote:

Originally Posted by Skippy

Exhaust leak?

Whats the best way to check for this? Would an exhaust leak be worse under load?

Cervan · #15 11-27-2007, 11:36 AM

Quote:

Originally Posted by dieseldan44

Whats the best way to check for this? Would an exhaust leak be worse under load?

an exhaust leak will allways be worst under load the most pressure is made in the exhaust system when the engine is under load. i usually put the car on jackstands and start it then go under there and feel around you will definitly feel and hear it where its leaking.