Explain this then?

Pipetech

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I have a V220 ambiente 1999 model.
This is a great vehicle apart from the usual tin worm.
Anyway i have tried several Forums and no-one has yet come up with a solution or even replied.
So am i the only person in the World to have this problem?

It is this when i start the vehicle any time it starts without fault, but makes a noise like something is catching.
Then after 10-15 seconds the engine revs rise by 200rpm est and the noise dissapears.
It has done this for 3 months, never alters dosnt get worse.
Then last week the heater plug light stayed on?
it was at this time i noticed that upon starting the noise had dissapeared?
so warning light on = no noise.
After searching the forums i found the red wire to heater plug relay had fallen off.
so i repaired it and, voila no heater plug warning light but noise returned.
So i tried the van with and without the red wire connected, and found when connected no warning light but noisy untill revs rise and red cable dissconnected no noise but with warning light.
Im starting to think it may be some sort of power drain that makes the engine tickover low and so vibrate causing noise?
Anyway i would like an answer please.
I dont believe i am the only person to have come up with this considering the millions of Vitos, V220s and sprinters around .
Please Help????
 

guydewdney

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Extra draw of glowplugs causing some extra strain on the alternator, making the noise. Disconnect alternator and test.
 

gazz

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Doh! Didn't read the post properly. Glowplugs do stay on for a short while after engine has started, so likely is current draw. Alternator may have a freewheel clutch on it too, worth checking that as when they seize up a heavy alternator load can make a vibrating noise.
 

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A seized alternator pulley is the most likely cause.
 
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Pipetech

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alternator pulley?

Hi many thanks for the replies.
Ifey how would this cause the problem? and if it comes and goes when i connect or disconnect the wire would that cause the alternator pulley to seize/unseize.
If siezed would the serpentine belt not burn out?

Many thanks again

Len
 

IanT

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Yes, this makes lots of sense and replicates what happened with my last W210 E320 CDI. Rattling sounding like a 'tinking' noise at and around idle, sometimes intermittently heard while the engine was cruising at around 1k rpm. Pulley clutch bearing replaced and no more noise.

The load while the plugs are on will be pretty unkind to the alternator and in turn this will make the idle rougher. You may find that holding the revs up a bit immediately it starts makes the noise disappear also as the engine is running at a smoother region of the rev range and avoiding resonance in the aux belt.
 
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Pipetech

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Ah well now you mention it when i start the car initially while its rumbling the throttle dosnt apear to respond and then when the revs rise all is well? and back to the alternator pulley issue, if the wire from plug relay is not connected why would the pulley be OK and when wire connected it becomes siezed?
I am going to check the pulley at the wekend but i just cant see how it can be ok and not ok just by connecting or not the wire to heater plug relay or am i missing something?
 

gazz

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If the freewheel pulley is seized, it will be seized all the time. It's only when the alternator is under heavy load that the seized pulley will make it's presence felt. At times of low load it will not be noticeable.
 

gazz

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In a modern diesel engine the crankshaft does not rotate in a smooth and linear fashion. It actually accelerates and decelerates with each cylinder's burn cycle. That is why they are fitted with torsional vibration dampeners, like dual mass flywheels, rubber composite front pulleys and freewheeling alternator pulleys. This is not an exact representation, but imagine swinging an empty two gallon bucket around on a four foot rope. We can almost replicate the action of the crankshaft if you extend your forearm out to full length and then bend your elbow up to 90 degrees twice per revolution. Now imagine the bucket has two gallons of water in as the alternator load goes high and you might get an idea of the reaction of the belt drive. The freewheeling pulley will damp out the oscillation and smooth the transition of load to no load and vice versa.
 

Dieselman

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The accelerator pedal lack of response is interesting.
I suspect the engine is idling too slowly so makes something vibrate. Once the electronics wake up and the normal controlled idle speed is attained the rattling stops.

I wonder if the gearbox or clutch springs are rattling.

Disconnecting the glowplug relay probably causes the ECU to adopt a limp home mode with set idle speed.

Check the air filter box has all its mountings intact.
 
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Pipetech

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Thanks again for the replies.
The vehicle is a V220 automatic so no looses clutch bits.
The noise when it apears seems to be from the drivers side of engine possiblt at the rear, where the alternator is.?
Also for some reason when the heater plug light was on for a week before i repaired it the car did NOT go in to limp mode.
So any more clues?
I think im going to get a new alt bearing for it even tho it seems ok.
Does anyone know if the special tool shown to remove the pulley can be fabricated or do i need one to get it off/

Cheers
 
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Pipetech

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Just an update.
fitted a new alternator Bearing/pulley and hey, NO difference at all.
I didnt think it would but following the replies on here it did seem a possibility, altho i could never understand how disconecting the heater plug relay wire would make the noise come and go? if the bearing was nackered it shouldnt have mattered wether the relay was connected or not?
Anyway im open to any more suggestions.
Thanks again Guys.

Len
 

def90cars

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Having the glow plugs on will cause a lots current pull. This may engage the alternator and most do have electromagnetic clutches to save fuel. I.e. only work when need.

From the t'internet

"I had a [Merc] whose alternator went bad. Put in a new alternator that had its own pulley attached, and all of a sudden, I had a noise similar to yours. It was then that I found out, that the old alternator had a "clutch pulley" that compensated for the power stroke of the engine. Switched out the new pulley with the old one, and the noise was gone. Later on, I checked in the trouble shooting section of the shop manual, and the lack or failure of the "clutch pulley" was noted as a possible cause of the noise you experienced."
 
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Pipetech

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Well chaps its SORTED, the noise was a crap (new) pulley off Fleebay. i put on a new alternator and wheyhey noise gone, still low tickover tho for a few seconds. So even tho the heater plug relay wire had been repaired i put a new relay on and VOILA all sorted.
so a big thankyou to you all on the forum, and if anybody has the same symptome you know what it is now.

Thanks again Guys

Len
 

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