Newbie needs help: E300DT Avantgarde 98 'Engine Rattle'

[BannyDoy]

Hi, I'm new to this place, having just got myself my first merc...
It's a E300DT Avantgarde 98 S reg.
I'm just kind of finding my feet... on the whole I'm really pleased with the car.
I was looking for anything relating to the kind of engine rattle you get when you come off the throttle.
I wondered if anyone could advise me further:

The rattle occurs warm or cold.... when you come off the throttle you get this sort of clatter or rattle that seems to be internal engine noise.
Help....
It just seems so smooth and wonderful in every other way...

(I responded to another thread that touched on the problem, but the title relates to a different issue... so I started this new one with a more relevant title). Hope that's ok...

 

[television]

Hello and welcome,,what is the mileage of the car, after around 150k it could be timing chain rattle, or if at the front of the engine the belt tensioner

 

[BannyDoy]

Thanks, it's great to join the club!
Yes, it's getting around that sort of milage...
What is the cost to recitfy those problems?
Can anyone recommend somewhere or someone in the S. Gloucestershire area to fix these cars without busting the budget (if you know what I mean)

 

[Parrot of Doom]

Check the belt tensioner shock absorber at the front of the engine. Right in front of the oil cap. The bottom bush tends to wear easily.

 

[BannyDoy]

ok I will have a look at that tommorrow.

If it ends up being the timing chain... is it adjustable or do you have to knock a link out or something?

 

[GEORGEROV]

If it aint the above then also check the engine mountings.

 

[BannyDoy]

I took a look at it all... decided that I just couldn't tell where the noise was from so I took it to a diesel engine specialist.
He decided that it was an injection related problem.
The phrase he used was "uncontrolled fuel". Apparently around the point of coming off the throttle or driving along at low revs you can get the rattle noise which is caused by an amount of fuel not being under control in the right way... (although I havn't noticed any smoke problems or excessive fuel consumption.... so it's not a major concern at this point other than the actual annoyance of the clattery rattle sound which spoils the whole feel of an otherwise smooth running lump of a beast).
ok. that was a wooly description of what he said.
I was told that there are injector nozzles available for £35 that are made in India that are to be avoided at all costs for being crap... and you can buy a complete new injector for around £45 each by Bosch. The job of replacement is 3-4 hours.
It might still rattle a little bit for a while longer but once they settle in the noise should go completely.
Can anybody relate to any of this???

 

[HERBIEMERCMAN]

hi banny, i have a e-300 td. with 190k miles. i have just spent £220 at merlin diesel experts in preston lancashire on a full set of bosche injectors. the chief mechanic who i have known for some time was confident this would solve the diesel clatter, which was slight on tick over and very loud at 1200 rpm.above this rpm, perfect. i still do not know what the rattle is ? may be the belt tensioner ? i have had the noise for 10k miles, it's just worsened lately, i dont think it is detrimental to the engine, it is just anoying. let me know if you find out what is causing it, if you ever find out. best of luck. herbiemercman. ( masachistic merc owner).

 

[simon_wall69]

I took a look at it all... decided that I just couldn't tell where the noise was from so I took it to a diesel engine specialist.
He decided that it was an injection related problem.
The phrase he used was "uncontrolled fuel". Apparently around the point of coming off the throttle or driving along at low revs you can get the rattle noise which is caused by an amount of fuel not being under control in the right way... (although I havn't noticed any smoke problems or excessive fuel consumption.... so it's not a major concern at this point other than the actual annoyance of the clattery rattle sound which spoils the whole feel of an otherwise smooth running lump of a beast).
ok. that was a wooly description of what he said.
I was told that there are injector nozzles available for £35 that are made in India that are to be avoided at all costs for being crap... and you can buy a complete new injector for around £45 each by Bosch. The job of replacement is 3-4 hours.
It might still rattle a little bit for a while longer but once they settle in the noise should go completely.
Can anybody relate to any of this???

I'd take it to a Merc specialist for a second opinion - belt tensioner sounds much more likely, spending £300 and another £150 on fitting new injectors may not help.

Belt tensioner noises are much more common on this car and would be a cheaper fix. When the car is idling, hold the revs at about 1000rpm on the throttle and see if the rattle quietens, if it does it's the tensioner.

 

[HERBIEMERCMAN]

97 e300 td. Engine rattle.

hi everyone, following all my injectors being replaced with bosch the rattle continued, much to the suprise and dismay of the diesel specialists, "merlin diesels" preston. however one member of the mb club took the trouble to inform me that he had the injectors changed and was told that after a short time and a few hundred miles the noise could dissapear, it's an ideosyncracy of the injectors. sure enough after some weeks and 400 miles this happened to my car, i was really suprised and pleased. the hypothosis is based on fuel cavitation, and minute particles of air. new nozzles give better spray patterns and more back pressure in the injectors, this condition helps irradicate the air and rattling, as well as improved combustion and mpg. herbiemercman.

 

[Number_Cruncher]

>>the hypothosis is based on fuel cavitation, and minute particles of air. new nozzles give better spray patterns and more back pressure in the injectors, this condition helps irradicate the air and rattling, as well as improved combustion and mpg.


I think it's a bit more likely that some particles of dirt got into the injectors or pipes while the system was opened, prevented the injector needles closing properly, and after a few hundred miles got pushed out of the injector tip.

 

[HERBIEMERCMAN]

hi numbercruncher, good point you raise, very plausable and less derogatory to the diesel specialist who carried out the repair work. herbiemercman.