lifter noise only when hot...'91 300d
 

hi guys. i have been a diesel owner now for about 2 years and have spent pleanty of money keeping it running... i have a 1991 300d 2.5 and overall the car is in beautiful condition. in spring of 2005 i began to hear a lifter noise. this noise came and went as the engine got hot as if a lifter was sticking. i took it to my mercedes mechanic and he told me that the easiest way to get rid of the noise was to replace the lifters(all 10). i paid him $800 to do the job and the noise was gone for about 3000 miles and then it started again. i took the car back and he poured in a can of engine cleaner.......which did nothing. i started to complain (big time) and he kept the car for a month and finally told me i ned a new cam shaft (which i have now been told should never wear) and charged me another $650. the car runs smooth and quiet until it reaches operating to normal temp, then a lifter tapping noise ensues. i am very mechanical and can tell the noise is coming from the valve cover area. a great mechanic told me that usually a lifter noise can be eliviated by adding a quart of transmission fluid to the oil and driving for 1000 miles then changing the oil again. (currently at 100 miles)
the car still drives and performs great........no loss of power.....no smoke (other then the usual diesel smoke)
anyone got a clue?????????
IS MY MECHANIC MILKING ME FOR EVERY PENNY I HAVE AND GUESSING HIS WORK???
why is the noise only when the car gets hot?

in an unrelated issue,this same mechanic has "adjusted" the shift linkages and vacuum shift module on my tranny and it seems to be good for a few weeks and then, slips going into first and sluggish between 2nd and 3rd. is the tranny shot or do i have a vacuum/adjustment problem??
a/c blows only from defrost and i a know it works on vacuum as well.......related?
car mileage is 269,000
has a new timing chain and sprocket as well


help before i burn it!!!
dee in savannah

RE: lifter noise only when hot...'91 300d
 

by chance am i hearing an injector noise that comes from the same general area if the car already has new camshaft and lifters???????

RE: lifter noise only when hot...'91 300d
 

the mechanic can easily differentiate between the injector and valve tappet noise.

if the noise comes only when the engine is warm, then it is the viscosity of the oil that is involved. adding atf to it can only make it worst.

what oil do you use? the noise was really "that" loud?

RE: lifter noise only when hot...'91 300d
 

as recommended, i am using 20w50 motor oil. the noise is very noticeable as soon as you open the door and even louded when you open the hood. the engine used to be very smooth with only a low level diesel chatter

RE: lifter noise only when hot...'91 300d
 

Just my theory, and it does seem to support thoughts I had about my own lifters (OM603) and my worn cam. I think when your new lifters were installed they became fatigued shortly thereafter with your worn cam, (a lifter must extend to it's max hydraulic action in order to make up for the gap due to a very worn cam....my cam is worn lobes, as much as 4mm!!

Introducing a new cam may have helped your engine to quiet lifters for a while but the new lifters were already compromised having operated to extremes with the old and worn cam.

RE: lifter noise only when hot...'91 300d
 

thanks for the replies!!
when the cam was replaced, it was to remedy the noise the "new" lifters had again started making. the replacement of the cam shaft made absolutely no difference. when i drove the car home from the repair shop (7 miles) i pulled in the driveway, opened the door and imidiately heard the "tapping" noise.
i have been driving the car all weekend (230 miles) and the noise is neither better or worse. i have found a vacuum leak which i intend to repair in just a bit, but have tried to rationalize the noise i hear.
if the car is not using oil, not smoking, or losing performance, i must not have a valve problem, right????
is my oil breaking down too fast???
what is "lucas" heavy duty oil stablizer for???
anyone got a clue what's going on or had this problem before??
is it possible that the cam was not installed right after replacing the lifters the FIRST time which caused a problem??
anyone got a match??? HELP

RE: lifter noise only when hot...'91 300d
 

You stated in your first thread that the cam was replaced some time after you had replaced the lifters?

Hmmm...I guess you have doubt about my theory? I was referring to hydraulic ware to new lifters, not ware to the lobe face of the lifter. It is plausible.

RE: lifter noise only when hot...'91 300d
 

maybe the oil pressure on the cylinder head is not enough?

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