OM603 cam chain tensioner refurbishment?
Are you sure it's cam chain? Unlikely unless very very high mileage, not something on serpentine belt. Does it disappear above idle?
Mine did the same
Wind on a new timing chain. I am not going through the process but theres loads of videos on line how to do it. I can do it easily by myself but its best with 2 people. Dont let the chain jump a tooth on sprockets and it will be fine. Also dont wind the engine backwards at all as i have seen it break some of the plastic guides
. The guides should all be replaced but i just did the chain and mine was silent after
PM me if you get stuck or call and i will talk you through the job 07977555923 after about 8.30 pm is usually good
G
Have you tried running engine without belt, won't harm it for a short amount of time? If noise still there, timing chain ? Gaz has a good spare engine
Slightly open ended question. The answer would depend on the mileage and condition of this engine.
I would firstly check the engine oil level. If the oil is old have the engine oil and oil filter renewed. I would prefer that the oil pressure is checked out with and independent oil pressure gauge. If you are reading less than 1.5 bar (guide line figure) at idle on a hot engine, the engine is indicating wear. Minimum is 0.7 bar at idle for petrol engines but figures for diesel I have never had to check.
If noise is still present this would indicate wear on the chain slides and or the chain its self.
M/B schedule do say that timing chains should be renewed at every 100,000 miles. But the cost is prohibitive for most that they do not do this.
I ask for these basic checks because not only is the tensioner under spring load there is also oil pressure acting on the tensioner.
If you are still adamant to strip the tensioner, bring the the engine to No1 cylinder at TDC ( always a good starting point). Turn engine in only CLOCKWISE direction. Once the tensioner is removed DO NOT turn the engine!
Strip tensioner and clean but re-assembly is only unidirectional. After drawing the inner piston out which draws out toward the chain side assuming the tensioner was in situ. Re-assemble feeding the piston from the nut cover side and fit in block. fitting in the spring and tightening the cover is not an easy task. After assembly turn the engine in only a clockwise direction enough turns to assume oil would have primed the tensioner, then start keeping finger crossed and hope there is no serious damage caused. Do not rev the engine immediately or very quickly. Do these gradually. NOTE: there is an element of risk here and neither I or the GWOA can be held responsible for any consequence of failure.
You might wish to check the vacuum-pump for the brake-servo. These are driven by a cam from the timing-chain area. They can fail catastrophically and destroy your engine.with tiny bits of metal casting getting everywhere. I think an imminent failure of this pump is what you may be hearing, rather than the timing chain.
The failure of the vacuum pump roller-cam mechanism is a known issue and replacement ones have an improved design:
Don't panic yet, you are running before walking as the phrase goes; Check the the timing chain and vacuum pump out firstly,then panic.
I suggest using a stethoscope or substitute with a long screw driver and place on the vacuum pump body or rocker cover or a suitable place on the front engine casing/timing cover whilst the engine is in start up and or running (get a helper to start) with the handle against your ear lobe.
RE: timing noise firstly do make sure the engine oil level is at the correct level; I think I have mentioned this previously then do the test. If either are noisy you will here the noise transmit through the screw driver. What mileage is the vehicle? OR before the engine has even started, remove the rocker cover to check on the slackness of the timing chain. You will just about manage to view the slider ether one at the left or right and see if can gauge if there is a deep channel worn into the slider where the chain drags its self on the slider surface, if so then you are looking at replacing these and. or chain as well. Tensioner problems are a rarity. Whilst the rocker cover is off look at the camshaft and surrounding; should there be heavy and thick deposits of carbon build up this indicative of poor maintenance and lack of frequent or timely oil service.
Evaluate from there on your options.
You do need to check all suggests out and do not please assume if said it has to be done; check and verify firstly, this will be cheaper on the long run.
I think it's fairly easy to unbolt from the front, but access may be a little tight. Once off it can be checked. The removal will also provide you with an opening to check the timing chain and its tightness. You may require a new gasket to re-fit.
It was a recommended precautionary replacement some years back and then when I looked it cost about £124 from MB. Probably double that today ? Pierburg are the OEM for the pump and it seems possible to buy the part from other sources with the MB logo having been ground-off.
If you need to change it, I would not recommend a used one, unless you can verify from the part number that it is the improved version.
Anyway, as Rakesh suggests, one step at a time.
more info:
http://www.benzworld.org/forums/w124-e-ce-d-td-class/1581960-vacuum-pump...
http://www.peachparts.com/shopforum/diesel-discussion/182725-new-style-o...
Here is some more information:
How to replace:
http://www.peachparts.com/shopforum/diesel-discussion/106614-how-replace-603-vacuum-pump.html
You may be able to find it cheaper, but here's one on eBay (at £240):
...and on Amazon at £190:
https://www.amazon.co.uk/Pierburg-7-20607-74-0-Vacuum-Brake-System/dp/B0068MW5Q6
Attached is the Pierburg (OEM) information (they blame the failure on worn cam discs). Check the cam disc whilst you are at it.
As i said replace chain as its a cheap option
If it is really noisey on tick over until revs pick up
im sure it will be the chain. If you think vacuum pump put a screwdriver to your ear on vacuum pump and other places on engine. Dont catch fan blades as it will be loud lol
Buy a cheap mechanics stethoscope they are usually less than 5 pounds
Before you get stripping it down
Start engine from cold for a few seconds and listen to noise
Then adjust injector pump timing after engine is switched off
At the front of the engine by vacuum pump there are 3 13mm hex headed bolts. These go to fuel pump at rear of timing chain. There is also one at the back of the pump, a little support bracket also 13mm
Loosen all these so its not too slack but finger tight
There is an 8mm bolt and some are 10mm down the side of the fuel filter to adjust fuel pump timing
Tighten the adjusting nut after marking fuel pump so you know how far you have moved it. As the pump is at half crank speed i would move it 2mm clockwise looking toward the front of engine from the rear flywheel end of engine
Tighten the adjusting rod and nut clockwise if i remember correctly
Tighten all bolts and start it up. i am sure you will notice a massive difference. It might still smoke a bit due to un burnt fuel from previous start but i bet its way more quiet
You wont hurt anything at all by retarding the timing no matter what any expert says. You will also find it will run and perform much better
Why is this???. Its because you have adjusted for timing chain wear and put the pump timing roughly where it was from brand new
I dont know how many miles yours has done but mine got noisey at 260k and i replaced chain. It was silent after that even on tick over
It might be the vacuum pump but most have been done and you would be un lucky to have a noisey pump as most failed years ago but i might be wrong
Let us know how it goes and there are plenty of images any videos to see if you are unsure. I say its easy but if you are not mechanically minded it can be a bit worrying
Good news, then !
Probably still worth checking on the condition of the vacuum pump and its cam disk.
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