Got a new 81 300td. She has 300k miles and is yellow. Shifts good drives good and does good at Highway speeds 70. There's no smoke at start up. At idle it has a knocking /tapping noise. At Highway speeds it goes away. When slowing down it isn't there until it hits idle. Sometimes when I drive to work 38 miles it goes away when I Park. It also idles ruff sometimes.
Had a friend look at it. He said it may be a leaky injector nozzle. (nailing?) so I cut out each injector by loosening the fuel line and #3 seemed to go away. I pulled injector and cleaned it. The noise is still there.
I haven't adjusted the valves yet.

Any help would be nice. I know om603 engines not the om617 very well.

Post video soon.

If you suspect an injector it's not enough to clean it, you need to have it tested for pop pressure and spray pattern. Contact forum member Greazzer, he can help with advice and/or injector service.

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1979 300D 040 Black on Black - 1985 300D Maaco job (sadly sprayed over 199 Black Pearl Metallic) on Palamino

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Here is a VID_20141101_175750.mp4 Video by epowers777 | Photobucketvideo

Anybody?

Not the easiest to tell from the video. But if you are saying that you have a knocking sound that goes away when you remove fuel from the suspected injector it's likely related to said injector.

To help narrow it down, you can move the injector to another cylinder (swap two injectors) and see if the noise follows that injector. If not then the issue is upstream (in the injection pump) or downstream (in the cylinder) and you can investigate further.

But for now the odds are good you just need the injectors serviced.

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1979 300D 040 Black on Black - 1985 300D Maaco job (sadly sprayed over 199 Black Pearl Metallic) on Palamino

http://i.imgur.com/LslW733.jpg

The Baja Arizona Oil Burners Send a message if you'd like to join the fun
Left to Right - UberWasser, Iridium, Stuttgart-->Seattle,, mannys9130

Visit the W123 page on iFixit for over 70 helpful DIY guides!

Whats your oil pressure lock? Valve adjustment ever done? At 300k, it can be a lot of things...

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I just did the valve adjustment some were really tight. One was OK. One took 2 hrs but sixto helped me out. Tapping is still there. When I cut injectors sound may lighten up but no it doesn't go away. I think maybe it's cylinder three (counting from the front) anyone think it's my flex plate?

Sorry having trouble with forum on my phone. After making the engine run better I noticed the noise might go away at Highway speed. Doing anything else it might get quieter like slowing down (rpms dropping). The knock doesn't come from from or bottom of engine. It seems to be cylinder 3.if I Crack the injector it gets quieter but doesn't go away.
So I'm think it's in the valve train. Could it be a lifter? Can someone explain how the lifters work and why they would knock?


Using tapatalk. It's all new to me. My phone kept crashing while on website.

Photobucket videos are really hit and miss on my computer - yours doesn't work for me.

Wear points on the OM61X valve train =>

The rocker arms are held in place on their own system of towers that have rods running between them. The rods can wear nasty steps in them but I don't think this would necessarily result in seriously noticeable tapping unless the engine has suffered from top end oil starvation. In this case you'd probably see evidence of camshaft and follower wear.

You could (if you wanted) remove the rocker arm assemblies and feel for any movement there and in the camshaft. Most likely culprit if we're talking valve train / chain related would be the tensioner (in my book) but with out seeing / hearing the video nasty tapping always makes me think of the intermediate shaft bearing that runs between the timing device and the IP.

So I'd be removing the vacuum pump and checking for any obvious play in the end of the timing device. That would be my first port of call.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Here is a YouTube video.
81 300td om617 knocking tapping: http://youtu.be/JQC9R-nuauk

Next step is remove valve cover and put up cardboard and start engine and use a scope. Gonna check all rockers.

It sounds like you have about four "ticks" per second but I haven't done an in-depth acoustic analysis on that!

At four or five ticks per second you are considering something that runs at half the speed of the crank at idle. Idle speed at 600 rpm == 10 revs / second (600rpm/60sec) => I know that that is a bit low for the idle speed of an OM617 but I hope you get a rough idea. Faster idle at say 800 rpm == 13.3 revs / second (or cycles per second = Hz in acoustic terms)...

...so something like four, five or six ticks per second indicates something ticking with the frequency of camshaft rotation speeds rather than crank speeds at the idle speed of an OM617.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

So your saying it's something in the valve train. I had a friend look at it he said it's not a rod nock. My idle is also really low.

So what is your suggestion. I'm positive it's cylinder 3 or 4.

I'm saying the tapping sounds like it is tapping at a speed that is approximately half of the expected idle speed. So with that in mind I'd be looking at camshaft / valve train related areas first.

I think it would be a good idea to remove the rocker arm sets from the engine and examine them. Whilst they are out I'd feel the camshaft up for any noticeable movement. If this turns out not to give any obvious possibilities I'd remove the chain tensioner and the sprocket from the camshaft and then see if there was a camshaft related problem.

If that wasn't it then I'd be looking at the chain tensioner and how that goes back together. Oil pressure is used to help the tensioner do its job. If there is a blockage or the tensioner is worn then you might get a bit of flapping from the chain.

If you remove the chain tensioner be sure to follow the chapter in the FSM for proper installation.

http://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/617/05-310.pdf

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Oh and because this is a relatively new to you engine I would most certainly consider at the very least the vacuum pump removal and check of any movement in the timing device / intermediate shaft area. This is a known weak point for the OM61X engines with the piston vacuum pump.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

OK thanks for your help. Hope to look at it next week. Tuesday. Will take more video and pics.