Noisy w211 e220cdi

[haydar]

Hi everyone

Wanted some advice on an issue I'm having with my w211 e220cdi. The car is a late 2002 and has covered some 100k miles.

The engine seems to have a clatter to it, which does not sound right. Reading previous reports I thought it might be the injectors and was on the verge of ordering some when the MB dealer tried some spares they had to just to check. It turns out that this did not solve the problem! (Lucky really as a set of 4 injectors costs £1400!!!!!!!)

So the question is, what could be the noise? Now there is also a noise from the rubber belt, which sounds like a bit of a whistle and when one turns the engine off there is sometimes a queak. This I've been told is likely to be the belt tensioner. Could this also be causing the clatter?

The MB guy here believes it could be tappets or something? Could it be anything else? Air con pump, alternator?

The one interesting thing was that just recently, after the car has run for a while, it does quieten down a bit.

Thanks for all advice.

PS. The car performs faultlessly. Flys up to over 125mph (200kmph).

 

[television]

The only bits that are known to clatter when faulty on the front of the engine are the water pump and idler wheel, there is an issue with a whisling sound from the serpentine belt. I have never heard of anyone changing the injectors from a noise point of veiw, the movement inside them is almost nil.

Malcolm

 

[jberks]

Clatters are hard to diagnose remotely obviously. I assume you've spraked the anciliaries with wd40 to see if that helps and it's not an alternator bearing etc. I'd be surprised if it's internal engine fault at 100k assuming it has a proper history and oil changes have been done properly - it should still be happy at 200k really. Anything is possible, but I'd suspect something daft like a water pump bearing.

 

[haydar]

The only bits that are known to clatter when faulty on the front of the engine are the water pump and idler wheel, there is an issue with a whisling sound from the serpentine belt. I have never heard of anyone changing the injectors from a noise point of veiw, the movement inside them is almost nil.

Malcolm

Macolm, when you talk about the idler wheel, is this also known as the belt tensioner, or is that something completely different? How would one know if the water pump is making the noise. The car does not even remotely get hot.

 

[television]

Macolm, when you talk about the idler wheel, is this also known as the belt tensioner, or is that something completely different? How would one know if the water pump is making the noise. The car does not even remotely get hot.

The only way to test the idler is to slip off the belt, and turn the pulley by hand, it should rotate smoothly with no lumps or roughness, if you can feel the bearings then it has gone.

Malcolm

 

[haydar]

OK, MB boys removed the belt and ran the engine. The noise was still there. Are the tappets know to wear out on this engine? Could the noise be coming from a faulty tappet?

 

[type49]

These engines also have a water cooled alternator driven by a one-way clutch. I have seen a few of these sieze and the simptoms are slightly lumpy idle, clicking rattle and very harsh and sudden stopping when switching engine off - can sqeek just as engine actually stops. The clutch can be easily checked and replaced in situ and bought separately from the alterator. Not a diy job though, due to a special tool required to remove. Shouldn't be more than an hour labour but I don't know the cost of the part.

 

[jberks]

I'd look elsewhere too. At 100k, if serviced properly, the top end shouldn't be worn yet. Anything is possible but this is unlikely.

 

[television]

I'd look elsewhere too. At 100k, if serviced properly, the top end shouldn't be worn yet. Anything is possible but this is unlikely.

these were my thoughts at the beginning, valve gear does not go at 100k, unless the chan tensioner has packed up, using a home made stethoscope the noise can be pin pointed.

Malcolm

 

[haydar]

OK guys, an update on this. Took the rubber belt off the front and replaced the belt tensioner. Noice got a lot worse. A real metalic click. Took belt off and noice completely gone! Put belt back on and noise is back! Then tried a belt that was slightly longer (12mm) and noise not so bad but definately there! Noice get's worse when AC is turned on, but mechanic seem pretty sure it's the water pump. With the AC off he (very carefully) stretched the belt tensioner and the noice was back.

With the belt off he shook the water pump pully and there definately was a click there. It's hard to be 100% sure without a belt the size one can by pass the water pump completely and start the car. Anyway, I've got a water pump winging it's way to Pakistan at the moment (a surprising cheap part at £100) and let's see what gives.

 

[haydar]

These engines also have a water cooled alternator driven by a one-way clutch. I have seen a few of these sieze and the simptoms are slightly lumpy idle, clicking rattle and very harsh and sudden stopping when switching engine off - can sqeek just as engine actually stops. The clutch can be easily checked and replaced in situ and bought separately from the alterator. Not a diy job though, due to a special tool required to remove. Shouldn't be more than an hour labour but I don't know the cost of the part.

This is really interesting because this is exactly what happens with my car? I wonder if I've made a mistake with the water pump???

 

[haydar]

Took car back to Mercedes benz and they said my Alternator was not the clutch type! Could the water pump be making the same squeak?

 

[haydar]

Question:
The noise that is heard is a metalic clicking! The noise got worse when the belt tensioner was replaced. Also, when the belt tensioner is manually extended while the engine is running, the noise get's worse. The noise is a loud harsh metalic click. The following items are connected to the belt, alternator, water pump, power steering and AC. So it's got to be one of these! With the AC off, the noise is still heard when the belt tensioner is extended so it's unlikely to be the AC. That leaves the alternator, water pump and power steering.
Which one of these can cause a metalic click? The power steering works flawlessly, the car gives no trouble from an electrical point of view and the car never gets hot. Even in a Pakistani climate. Please help.