Hello,

I have a 1978 W116 300SD. I've had it now for a couple of months and have noticed that it has a "ticking" sound coming from the engine compartment.

I've cleaned the banjo bolt, adjusted the ALDA and made sure all links move to full stop and are unencumbered. I've changed the fuel filters as well as a Diesel Purge. The car sounds like a diesel should except for this &$^% ticking sound which is annoying me.

The car gets great mileage, does not burn oil, and moves far faster than I would have expected. I've taken a long screwdriver and "listened" to the injectors, IP, PS pump and anything else I can get to without getting caught up in the fan with "normal" sounds coming from them all. I tend to hear the sound more at idle than speed, but it does go up with the throttle and then "disappears" until I'm under 2K.

I did notice today after the purge it seemed to come and go, which is new for this issue. So long story short....anyone have any ideas? Is it a injector, or vacuum pump? I want to say it sounds like it's coming from "behind" the engine. If my ears don't deceive me, I'd say it's stronger on the drivers side of the engine compartment vs the passenger side.

Could this be a exhaust issue? Your help would be greatly appreciated...as it is driving me nuts.

Best Regards,
Duke1

Have you adjusted the valves lately?
Is the pressure control on the IP (banjo bolt) giving sufficient fuel pressure?

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1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
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layback,

I have not yet done a valve adjustment...but I have the wrenches and am planning on doing so. Could that cause the ticking? As for fuel pressure..I don't have a gauge to determine this..but after adjusting the ALDA and cleaning out the banjo bolt, it went from sluggish to down right fast.

Thanks for the response.
Duke1

I recently adjusted my valves, and found that several were very tight. Now that they have been done, the ticking is still there, but it will go away when cold, and in gear.

At start up, the ticking is still present, then in gear, it will be "quiet" until the vehicle warms up.

Is this an oil issue? Is it thinning out and then not lubricating something properly? I use Chevron Delo 400 15W40 (what they sell at Costco).

Today I took my air cleaner off and checked all the intake and exhaust bolts and everything was tight. I checked the engine mounts and they seem fine, I also checked the heat shield over the starter as well, all was tight. The noise seems loudest from the passenger side, and it appears to be localized between the middle of the turbo and where the motor connects to the transmission. It sounds like it's at or above turbo level. When I used a long screwdriver to "listen" I couldn't hear anything that sounded like the "tick tick" noise that I'm hearing.

I made a video of it, and I'd appreciate your thoughts on what it might be, or what I should continue to check/eliminate as the cause.

I'll post a link to the video momentarily.

Thanks,
Mike

Here's the video link.

Thanks

http://www.youtube.com/watch?v=NKCJf_rnbIs

When you stop the engine something is rattling away just as the engine dies and it sounds like a spanner or an allen key jiggling away somewhere.

I have had similar with a Bmw,I dropped an allen key and it went down behind the alternator.

My 1990 w124 300d om603 has had a couple of injector lines not secured in their clips properly and they make a lot of noise,placing your hands on them will see them go quiet.

Not familiar with the 5 cylinder engine and the throttle linkage setup but what is moving around mid rocker cover between injectors at start of video .

murkybenz,

That was an fuel injector return line. I'll check the lines, but it really sounds like it's coming from the passenger not drivers side.

Thanks

that's one of those noises that's really hard to put in video... sounds like it could be injector related. the return pulse is identical to the ping pulse. have you tried cracking injector line nuts one at a time to see if the noise stops on one?
it could be a exhaust manifold leak, or a problem with a starter engaging after the car has started.

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My drivers:
1987 190D 2.5Turbo
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1987 300TD
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So to crack the injector line I would loosen the nut where it actually joins the top of the injector and not at the IP right? I can do this safely while running and not screw something up. How far should I crack it?

I'm willing to try.

thanks

Yes, just loosen (do NOT remove) the nut on the pipe at the injector while running. Do this one line at a time. Fuel will escape, but diesel isn't very flammable so don't worry about fire.

Do not overtighten the nuts when finished. The spec is 25 Nm, which is not a lot for a 17mm fastener.

D.

__________________
David Bruckmann, Oakland, CA

Current:
66 Citroën DS21
72 MB 280SEL 4.5
73 MB 450SLC
76 Citroën 2CV6
76 MB 300D
79 MB 300SD
Past:
70 Citroën DS21 (170kkm)/71 Citroën DS21 (137kkm)/72 Citroën DS21 (502kkm)/78 MB 300D (1,200,000 km-ish)/79 MB 300D (425kkm)/79 MB 300TD (260kkm)/81 Citroën 2CV6 (120kkm)/88 Merkur XR4Ti (209kkm)/81 Peugeot 505 GRD (350kkm)/84 MB 300TD (385kkm)/85 Toyota Camry (330kkm)/86 Renault 9 1.7L (155kkm)/02 Golf TDI (74kkm)

Damn! Is that how still a 617 is supposed to be at idle?

I've got some work to do.....

__________________
----Adam

1985 300SD 322,000

Here is my "new" rebuilt engine, it's idling too high in this video:

http://gallery.me.com/cbaronxxx#100225

Ok..I'll give that a try tomorrow and report back. Thanks for the advice.

Based on the area the noise is coming from, is it possible you are hearing an exhaust leak?

Well here is he latest. I cracked each injector until it was spurting fuel, and the tick was still there.

I listened again (twenty minutes at least) with a wooden dowel and I couldn't hear anything that wasn't sounding like it should. I re-checked the engine mounts, alt, v/pump, IP, injectors themselves etc etc.....nothing.


I got under the car and it sounded like it always has, coming from the upper rear portion of the engine. It's a rock steady "tick tick" with the RPM's that does go away (or is masked by the sound) after 2 to 2500 RPMS.

I even re-checked my exhaust bolts etc...a couple turned just a tad bit more..not much. I'm out of ideas...but if I had to put my money on it...I'm thinking it must be an exhaust leak.

I can hear it loudest by cylinder 4&5 and where the exhaust manifiold joins the block, there is some oil out the bottom of the gasket....could this be it? If so, a new exhaust gasket and it should go away?

Once again, your thoughts are appreciated.

Duke1