W202 Squeaking and rattling noises From front area of engine

[Aussie Nick]

Hi Mates.
Last Saturday I replaced the front shock absorber belt tensioner on my c200 w202. Prior to this there had been a constant rattle emanating from under the front plastic cover.The local lads at the MB dealer suggested that i replace the shocker tensioner, which as indicated above i did. All rattling sounds disappeared and the whole car appeared to run smoother for one day.Today I engaged the air conditionerand discovered that I was hearing more serious rattling rumbling and screeching. The power steering also feels sluggish.The noise reduces considerably with revving the motor away from idle. Also there is a definite reduction in the amount of noise when the air con is disengaged notwithstanding that rumbling is still audible, This rumbling was not present before.

Any suggestions ?

 

[television]

It will be the idler wheel on the tensioner, Anyweb has just replaced his with the same post

 

[Aussie Nick]

Thanks Malcolm, lightning fast as usual

 

[anyweb]

sorry but i didnt replace the idler wheel Television, and never posted back what happened after i got the tensioner damper arm replaced due to being stressed, but that's another story.....

replacing the tensioner damper arm did indeed fix a lot of the noise issues in my engine but one remained (a clicking or ticking which comes and goes), i thought it was the pulleys/wheels but my local indie insists the noise is coming from within the engine (under the head) and most likely from the valve lifters or vavles themselves, indeed he held up what looked like a stethoscope to the various parts of the engine including said wheel/pulley and the noise was not eminating from there.

too costly to fix so best to leave alone, well i'm no mechanic and the cars driving fine so i'll stick with it

he did however say that some good STP valve oil treament 'may' help.

cheers
anyweb

 

[Marvinstockman]

Bad AC compressor clutch bearing?

 

[Aussie Nick]

Thanks ..Will investigate tomorrow. Thanks Anyweb the diagrams have helped .I have replaced 29. It may be no 5 (belt tightener/tensioner) Or as suggested by Marvinstockman AC compressor bearing. It does sound like failed bearing noise. Will cut off short length of garden hose tomorrow in daylight and try to establish where noises are located.
Regards

 

[Marvinstockman]

If it's the clutch bearing, it is replaceable without replacing the compressor. Remove the belt and turn the pulley by hand - feel for a bad bearing. You can do this with all the accessories after the belt is removed.

My compressor clutch bearing knocks when the compressor starts up, and when the engine drops to idle falls. It stops after a second or two.

 

[Aussie Nick]

Ta for that Marvin. Mechanic is saying it is the tensioner,which is no 5 in Anyweb's diagram which is the whole bulky assembly. Have been quoted AUS $173 for genuine part or $125 for non genuine.Supplier suggests to stick to Genuine as there were problems with non genuine. Have to go crosstown to get this frigin part now .The car has hit 234000 km and now these problems are coming one after the other. I notice that these problems always coincide with extreme weather changes principally hot weather.
Will report back shortly.

 

[Aussie Nick]

HI mates.
The problem proved a little more complicated than originally suspected. You will recall I had a minor rattling noise arising from the front area of the motor. The noise was emanating more specifically from the tensioner damper arm. I carried out the prescribed test of pressing down on the damper arm top, with the motor running. This seemed to remove the rattling noise although there was a slight very minute and subtle clatter, which was presumed to be idiosyncratic of the normal operation of the engine. The damper tensioner arm was replaced with a new one . A couple of days later on a hot day,the rattling reappeared much louder than previously together with some rumbling and whining, all of which was concentrated in the same area as previously considered. The noises were considerably more severe when the air con was engaged and the motor was at idle
The tensioner pulley ( No. 20 in the Anywebs attached diagram) became under suspicion.Today the belt was taken off and a new tensioner pulley was purchased . Removal of the old tensioner pulley disclosed that it was totally defunct through wear and tear. Unfortunately it was discovered that the new tensioner damper arm (only a few days old ) had been severely damaged in the area of the round rubberized ring at the top of same . Accordingly it was necessary to replace this part again.
It seems that the the pressdown on the tensioner damper arm test, is not always a reliable test to determine whether the tensioner damper arm is the only problem when these noises first appear.
It seems, (and Anyweb should heed this information ) that the wear in the Tensioner pulley causes a failure of the damper arm tensioner.
I guess the lesson to be learned here is that if you hear the noises described above then it is probable 1 that the tensioner pulley is, or has failed and that 2 the tensioner damper arm has been damaged by the the failure of the tensioner pulley.
All in all it cost an additional $425.00 AUS including replacement of the drive belt which showed signs of minute cracks

regards Aussie Nick

 

[anyweb]

great info aussienick thanks for posting it,

i know that two days after my tensioner arm was replaced the noise was worse, this was because the bottom bolt holding it in came loose, we removed it, refitted and used locktite for the bottom bolt, it hasnt shown itself again (the fault)

however i'll certaintly keep in mind about that pulley

cheers
anyweb

 

[anyweb]

All in all it cost an additional $425.00 AUS including replacement of the drive belt which showed signs of minute cracks

regards Aussie Nick

what ??? that sure is expensive ! the tensioner arm alone can be bought direct from mercedes dealers (i bought it) for approx 60 quid (80$)

i dont see how it ended up costing that much..

 

[Aussie Nick]

Yeah I think I was ripped off a tad. One of the "gentlemen " who carried out some of the work left a rechargeable LED inspection lamp in the engine compartment. Very nice of him really. I guess he took pity on me and thought I may need to do all of my own repairs hereafter ....... especially as I had contributed so generously to his personal Christmas fund. Hang on....... I dont think he celebrates Christmas.

 

[television]

Yeah I think I was ripped off a tad. One of the "gentlemen " who carried out some of the work left a rechargeable LED inspection lamp in the engine compartment. Very nice of him really. I guess he took pity on me and thought I may need to do all of my own repairs hereafter ....... especially as I had contributed so generously to his personal Christmas fund. Hang on....... I dont think he celebrates Christmas.

One thing is for sure "He did not see the light" so not very religious