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Discussion Starter · #1 ·
Hey,

Recently I had to replace the timing belt, water pump and generator of my car and since then I noticed a weird sound from the engine compartment, it was a bit like a whistling tone.

I could hear the sound with a cold engine the loudest although it was still there with a hot engine.

First I thought the thrust bearing of the clutch was worn out. I went to the garage and let the mechanic do a test drive, he assured me that the thrust bearing is still doing fine.

A friend of mine, who's a mechanic as well, drove along with me to check the sound for himself and he also concluded the thrust bearing was fine and the problem is most likely a tensioner of the timing belt or serpertine belt.

So I went back to the garage that replaced the parts and the mechanic went for another test drive. He told me it could not be the timing belt since the tensioner is automatic and the serpentine belt was still doing fine as well.

Today I inspected the engine compartment, I switched on the engine to hear for myself where the sound is coming from. The sound is from the generator or the pulley at the serpertine belt.

Does anyone have an idea what could be wrong?
 

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Could be the replacement Alternator...

The problem with a noise as described, is that other than some checking with a stethoscope the only way to isolate it starts with serpentine belt removal.

Then you'd start the engine momentarily to see if it disappeared, and if so spin the individual components driven by the belt to look for one that isn't turning smoothly/makes noise/feels loose.

Not the easiest to trace.
 

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As Sailor said, the alternator is definitely a suspect. Before removing the auxiliary belt, put the engine in idle and progressively load the alternator by turning on shield heaters, headlamps, fog lamps, etc. and see if the noise gets louder. If I were you, I would have replaced the auxiliary belt as well, especially if it's the stretch type. You also don't mention if the timing tensioner was replaced, which should have been.
 

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Discussion Starter · #4 ·
Thanks for the replies!

I greatly value your helpful replies, however I am not going to touch the alternator at all. A garage replaced it and I have lawful warranty stating they must fix this issue at no charge.


I already localized the sound by using a screwdriver to "feel" extra vibrations at the idling belt and alternator pulley, the latter vibrates much more. Also by just listening closer to the alternator I figured out the sound is coming from there.


Could this be because the alternator is incorrectly configurated or the pulley is just broken, despite the fact it's a new alternator?
 

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It looks like you have isolated the root cause. Alternators are simply mounted, connected and checked for correct output so no configuration or balancing is required. Unfortunately I've seen many instances on this forum of new alts failing and I do suspect that a good number of "new" alts out there are actually refurbished or share components from replaced units. In fact, I do get a good discount by the dealer whenever I return an old alt for a new one, so there must be a reason for that !

Simply go back to the garage and request a new one. It seems to be that simple in your case.

Cheers
 

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Discussion Starter · #6 ·
Thank you very much!

Should it be known to the garage that the alternator is refurbished? It's a universal car dealership that has a reasonable reputation in the area and I can't really find complaints on the internet about them, however if they charged me for a brand new alternator while installing a used one I don't really appreciate that to say the least.
 

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As in everything, there are honest and dishonest mechanics but it is highly probable that he wouldn't even know himself the origin of the product. One might also argue that if it had to be 100% brand new, we would have to pay way more. It's the age of recycling I suppose !
 

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^^ And it's hard to tell what quality level you're getting, an inexpensive 'new' unit may not be nearly as good as a quality rebuilt one. Unfortunately most "rebuilts" are very cheaply done & have a poor reputation over here.

I looked for interest & saw a listing for a "new" unit to fit your car advertised for 211 EU. That's the same range as for what should be a decent rebuilt. Typical OEM new replacement would likely be at least twice that price, and these are "discount" prices lower than you'd receive when having the work done.

Shops generally source parts that they have had good luck with in the past, and that are warrantied to them. Having to do it over for a bad part looses money, so they try to avoid using the "cheapest' as a rule.

It still can happen, so all you can do is take it back & point out the issue.

Luck.
 
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