It's Ticking, will it explode - ML-270CDI

[Mark A]

When sitting stationary my 02 ML-270 has a loud ticking noise. At first I thought that it may be the injectors again, but alas no. The noise seems to be coming from the front of the engine around about where the belt is. I have had a good look and ca't see anything rubbing on belts / pulley / fan. The noise dissapears as soon as you touch the accelerator, and can also be heard when coasting to a standstill. Any ideas on what it could be - my other half is getting fed up and wants to PX for an X5 but I don't.

Help appreciated - Mark

 

[roadhog]

Could it be hydraulic tappets? You could try something like Wynns or Forte top end treatment and see if it helps.
I have a similar noise on mine and can't make my mind up whether it's the tappets or the injectors.
There's a procedure for mine to test the tappets, it involves running the engine at 3k rpm for 5 mins then taking off the valve cover and checking for play between the camshaft and the tappets. Not sure if it's as easy as that on your engine though.

 

[Mark A]

Cheers Roadhog. I have just come across a post suggesting that it could be the one way clutch mechanism on the alternator. I will have to have a good look.

Mark

 

[Mark A]

ML-270 alternator removal

Is there a step by step guide for getting the alternator out and tensioning the V-belt ?

I was going to give it a go myself, but I see that a special tool is required for removing the bolt. My Merc garage hasn't been too helpful with supplying the parts or the tools, they just want to sell me a complete new alternator - didn't even ask the price.

Mark

 

[Mikimogo]

Ticking alternater (Put your fingers in your ears)

Hi,
Sounds like iether a broken or loose segment on the armature in the alternator or could even be a carbon brush in the alternator worn almost right down and skimming the armature segments unevenly, giving the ticking noise as it hits the gaps in between the segments.
Rgards,
Mick.

 

[mattkh]

Is there a step by step guide for getting the alternator out and tensioning the V-belt ?Mark

Hi
Can you put up a picture of the rear of the alternator please.

 

[Mark A]

I have now fixed the problem. It was the alternator pulley. Once I dropped the fan out, I could get much better access. Unfortunately the tool I had purchased off e-bay along with the pulley had to be modified to work properly. I will try to take some photo's tonight & post them.

Thanks for the help guys.

Mark