Benz 300d 5 Cyl. - Noisy Lifters

[LCAN]

Hi All
Can any of you help me resolve a problem I am having with a M Benz 300 D There is a hell of a rapping noise coming from the front of the engine sounds like a thrashing machine. I first diagnosed it to be the lifters & have replaced them all. however this did not resolve the problem. I have since replaced the camshaft, ground the valves & seats, replaced the rings, bearings,& pistons, timing chain, sprockets, tensioner and chain guides . after assembling the engine I proceeded to check the valve clearance according to the M Benz manual which instruct you to check the clearance by holding down the lifter & check for a clearance of 0.40 mm ( if more than 0.40mm the lifters should be replaced.) In spite of having all new lifters the clearance was greated than 0.40mm. I then installed a second new set with the same results ( greated than 0.40mm ( yes I did soak the lifters in oil prior to installing them and I also pumped them up by depressing the lifter for 20 -30 seconds in the pan of oil) If anything I would have expected the valve clearance to be too tight after grinding the valves. I have now replaced the cylinder head still no improvement. I now have spent $3900.00 and am wits end as to what to do other than replace the complete engine. If any of you have any suggestions please , please I am open to all.
thanking you in advance for any suggestions you may provide

M.C. Murphy

 

[Bolide]

Noisy 300D

You don't say what year of 300D this is so I'll assume it's a 1986 - 1993 W124 300 Diesel non-turbo six

The damper on the serpentine belt tensioner rattles like a good un when the metalastik bush at the top mount breaks up. You can test it by reaching carefully behind the fan and pressing the top of the damper towards the block. If the noise stops, replace the damper. That'll cost about £20

Apart from that, these engines are pretty talkative. Assuming the hydraulic lifters are OK and have suitable oil in them, and it's not the damper, you'll have to decide if it's a reciprocating or rotating noise. If it's the former it'll likely be valve gear. If it's the latter I'd look at the serpentine belt idlers & everything else driven by the belt and work by a process of elimination. What happens if you take the serpentine belt off and run the engine?

Nick Froome
www.w124.co.uk

 

[LCAN]

M Benz 300 D Noisy

HI NICK

THANK YOU FOR YOUR REPLY I MUST CONFESS THAT I DID NOT GIVE YOU THE FULL DETAILS OF THE ENGINE DESCRIPTION. I DID THIS ON PURPOSE BECAUSE THE ENGINE IS A FIVE CYLINDER DIESEL ( MB 140 D ) AND IT IS IN A SSANGYONG MINI BUS THE SAME ENGINE IN THE MUSSO AND OF COURSE IT IS A M BENZ ENGINE I ASSUME IT IS MANUFACTURED IN KOREA UNDER LICENCE BY BENZ. I FIGURED IF I MENTIONED THIS NO ONE WOULD REPLY TO MY REQUEST.

I HAVE DISMANTLED THIS ENGINE COMPLETELY AND INSPECTED EVERY PART WHICH MOST OF THEM HAVE BEEN REPLACED. THE NOISE IS CONSISTANT WITH ENGINE RPM. MORE NOTICABLE TO THE TOP FRONT END. SURE SOUNDS LIKE LIFTER NOISE BUT SEEMS TO BE A LITTLE TOO HARSH TO BE LIFTERS. i JUST SWAPPED THE TIMING CHAIN TENSIONER WITH THE OLD ONE ,HOWEVER MADE NO DIFFERENCE. ??????????? ANY SUGGESTIONS OTHER THAN DUMPING THE ENGINE INTO THE MEKONG REVER. ( i,M HERE IN LAOS AND HAVE VERY LIMITED RESOURCES TO CALL ON. )

sINCERELY & DESPERATE

MIKE MURPHY

 

[Bolide]

Noisy 300D

If it's harsh and it's rev-related, is it the combustion process? Is the injection pump timed correctly? Are the injectors worn out?

Nick Froome
www.w124.co.uk

 

[tom7035]

I'm no diesel mechanic, but I think Bolide is on the right lines here. I've mingled with guys who work on 'oilers' and the term they would use for this is 'sounding a bit sharp' - a reference to a little over-advanced pump timing?