With much help and useful suggestions from the forum community, as well as visits to several local mechanics in the West Palm area, I have pretty near concluded that the tick tick tick noise my newly acquired 1980 300TD wagon is internal, and probably a rod bearing.

But Skippy had a "silly question"; is the ticking noise occurring 6 or 12 times per second at idle; that if it were 6 times per second, it would NOT be a rod, as the crank is spinning approximately 12 times per second at idle.

It is definitely about 6 times per second, not 12. So now I am perplexed.

Have an oil pan gasket on the way from Pelican, and will remove the lower oil pan when it arrives. Wondering what to look for in there in terms of play. I know to look for metal filings, but would there be any play in the portion of the rods I can reach from there, and would it be sideways, up down, or what?

Also, I have a quantity of old but clean and un-used 90 weight gear oil.

Wondering if mixing a couple of quarts of that with the regular engine oil would be a diagnostic tool in that a bad rod might run quieter with the thicker oil, or possibly even running such a mix if I chanced a 1500 mile trip with it ticking.

There is good oil pressure, no burnt smell to the oil, and the temp stays right at 80C.

Thanks again folks for all your help.

ed


1980 300TD Wagon with unknown different turbo engine.

Be sure to check the Pan for Metal Fragments.

I think if you loosen the Fuel Injection Line Nuts a the Injector if you actually have a Rod knock the sound is going to go away on that Cylinder when the Fuel is cut off to the Injector.
Re-tighten the Fuel Injection Line Nut and move on to the next Injector.

If you do that to all Injectors and the sound is the same I would doubt if you have a rod knock.

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84 300D, 82 Volvo 244Gl Diesel

Cracking the injector nuts made the engine slow down more or less equally on each one, but did NOT make the noise go away. Nor did adjusting the valves.

Poking around the various pullies and different parts of the engine, could not isolate any particular area where it was louder, except the injector pipes. They were missing the little clamps that hold them together, but I got some today, and it made no difference.

I wish I could post a video of the noise as some have suggested, but stuck with dial up for the moment, and could not even post a photo.

Any thoughts on the 90 weight?

ed

Strong nailing
Strong nailing - PeachParts Mercedes ShopForum

Injector + Heat shield + Nozzle, Prechamber + Collar and Nailing. LINK THREAD
Injector + Heat shield + Nozzle, Prechamber + Collar, and Nailing. LINK THREAD - PeachParts Mercedes ShopForum


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Ball bearings found in pick up screen. - PeachParts Mercedes ShopForum

Vacuum Pump Rebuild Thread
Vacuum Pump Rebuild Thread - PeachParts Mercedes ShopForum

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Diesel Timing Chain Links Thread
Diesel Timing Chain Thread - PeachParts Mercedes ShopForum

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Diesel Injection Pump Timing Device threads - PeachParts Mercedes ShopForum

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Diesel Harmonic Balancer threads - PeachParts Mercedes ShopForum

Main seal front/rear and harmonic balancer + Pulley
Main seal front/rear and harmonic balancer + Pulley - PeachParts Mercedes ShopForum


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1983 300D
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I think that makes it less likely that you have a Rod Knock.

You can listen with a Mechanics stethoscop, a piece of Broom Stick or a really Big Screwdriver with one end on the Part and another end on your Ear. However, watch out for moving and hot Parts.
How about the Vacuum Pump?

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84 300D, 82 Volvo 244Gl Diesel

Six times per second would be the cam shaft or a combustion event.

I don't like the heavy oil idea...

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

I would suggest to forget the heavy oil, keep the oil level up like normal, and drive it like normal, but keep your ears open. If it is a rod bearing, it ain't going to get better by itself, and yes, you don't want to damage the crank if possible, but your chances of slight or more damage until the sound gets pronounced is not great. Drive it, but not like you stole it!

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

Also, I have a quantity of old but clean and un-used 90 weight gear oil.

Wondering if mixing a couple of quarts of that with the regular engine oil would be a diagnostic tool in that a bad rod might run quieter with the thicker oil, or possibly even running such a mix if I chanced a 1500 mile trip with it ticking.

There is good oil pressure, no burnt smell to the oil, and the temp stays right at 80C.

Thanks again folks for all your help.

ed

Taken from another forum:

I have posted this chart to be used as a reference. It basically shows how to compare oil viscosity between different viscosity ratings. An example would be to show that an SAE 50wt ENGINE oil is close to the same viscosity of 90 weight GEAR oil at operating temps. It can also be used when comparing UOA's as some labs use Saybolt (aka: SUS) viscosity while some use Kinematic (aka: cSt) viscosity.

http://i304.photobucket.com/albums/nn169/White_Buffalo/oil%20analysis/viscosity_chart.jpg

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96 E300d

You can buy a mechanics stethoscope for less than $20 at NAPA/Orielly, etc.. With it running, you place the metal probe against the engine and listen. You move it all over the engine, front to back, side to side, top to bottom. You place it on each injector, including each injector pump port, all over the pump, vacuum pump, cam cover, cam cover bolts, exhaust bolts, pan bolts, accessories and their mounts, including pulley hubs (being ever so careful around obviously MOVING parts).

You attempt to isolate the location, as well as severity of the sound and its possible cause. Rods dont generally tick, they KNOCK. And they dont generally take very long to go from silent to BOOM/total engine failure/rod through the side of the block. Especially on diesels as they have a much harder ignition shock.

If the noise sounds half speed, its obviously cam and valve related, but I totally disagree with the suggestion to keep driving it, at least until your sure of the cause. I have seen a lot of engines suffer catastrophic damage after a cam bearing seized, a valve dropped, a prechamber came apart, a timing chain or chain sprocket let go, etc., etc..

I would sideline the car until you know exactly what is making the noise, and then repair it. If something is hammering, its only going to get worse until something breaks.

Heavier oil will often quiet noisy lifters because it takes longer for the heavier oil to leak out of the worn out lifter, and it may give extra cushion to a loose bearing. But you cant fix a major mechanical failure with thicker oil, it needs to be repaired. Its quite possible that too heavy of oil will overwhelm the relief valve and dump excess flow overboard. Your gauge will show higher pressure at the filter housing, obviously, but it could be lower actual flow out at the ends of the galleries resulting in oil starvation.

Think of it like having thicker blood. Heart works harder trying to maintain flow, creating higher pressure at the heart, but could be almost zero flow out at feet and hands. If it is a rod bearing and you starve it of oil, youll have a lot more to fix if it dont like it. 15W45 should be plenty. If its knocking on that, its tear down time.

Got a stethescope at Harbor freight for just $3. The injector hard lines are loud, more or less equally so. Other places on the block, head, valve cover, oil pan etc, the sound may be heard faintly, with no area more pronounced than the others. The pullies had their own noises, but nothing like the ticking sound.

Wondering if I'm wasting my time to do the oil pan, if I should take the valve cover off again and observe the engine running with it off. Didn't notice anything fishy looking under there when I adjusted the valves the other day.

Any ideas?

ed

That only works with hydraulic lifters. The OP has an OM617, which has solid lifters.

The tick is happening at valvetrain speed, which is also IP speed. It's either a valvetrain issue (very likely) or a fuel system issue (considerably less likely after the diagnostics that have been done). I wouldn't bother pulling the pan, since the problem is not down there. Pulling the valve cover and closely inspecting things might help. If you can't find the cause, the next option might be to continue driving and let it develop.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Went over it again with my trusty H.F stethoscope, and the sound is a bit louder in the front of the chain portion of the valve cover, especially near the center of the circular portion. Also on the corrugated aluminum pipe that goes to the turbo, and a tubular shaped casting that is just below the air cleaner next to the passenger side of the block.

Not nearly as loud as the injector pipes, or just the sound in free air w/o the scope, that seems to have no defined direction.

So I will be taking the valve cover off again and wondering what to look for.

The only other 300D I had with a chain issue, made a kind of rattling jangly noise. This does not, only the tick tick tick.

Thinking I will hold off with the oil pan, as per suggestion, & b'cause the noise does not seem to be coming from that area.

Thanks, and please advise. If it's the chain, can I get maybe 1500 miles out of it b4 replacing?

ed

I had a similar tick tick sound and it turned out the Timing Chaing Guide in #89 in the pic was loose.
It also would be nice to be able to remove the Vacuum Pump and run the Engine and see if the Noise goes away. But, there is no easy way to cover the hole and runing it without something to cover the Hole would case a mess.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

You can run the engine while cold and at lower speed with the VP removed and you won't lose any oil. I've already done it on an extra engine I had.

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'83 300D, 126K miles.