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Technical Siren-like noise at high revs on cold engine

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Technical Siren-like noise at high revs on cold engine

noise at high revs on cold engine
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1) this is a bad idea, and your engine will be dead pretty quickly if you keep it up :rolleyes:

2) Its 95% gonna be the cam belt tensioner bearing! Or 5% chance its the water pump bearing. they all do it. don't worry, getting a new bearing it will not make the noise until about 1,000 miles, then it will be just the same noise again.
 
could just be that the gearbox is cold, try popping it in a higher gear for a bit for example 3rd very soon after 2nd etc. so the car is slightly sluggish a bit seems to make the gears smoother and warms them up quicker. not only that it keeps the revs lower (say below 2000 - 2500) so you wont get the noise ;) and the engine has had a chance to warm itself up.

btw dont laugh but I saw this on an old Dave re run of top gear lol richard hammond did it on a car lol.
though he was taking the p*** but works on those icy mornings.
worth having a go before taking to a garage or parting with cash!!

Cant beat topgear on Dave!!!:)
 
Ben_uk said:
Any different on a 16v ?? i got a punto sporting.

thanks ben
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will be a little difference as its a completly different engine


i must admit my punto 1.2 8v does it aswell.. its going in for the belt tennsonier for the 4th time after fiat saying theres nothing wrong with it... i have a video this time :devil:, marsons are incompitent *****, mine only does it when its been wet i tend to find though

oh btw the recomended cambelt change on an 8valve fiat is at 60,000 or 5 years not 72.. just to clear that one
 
I changed the belt and tensioner ( 1.2 8v '03 56000mi ) and the noise started after I did the job - so I tightened the alternator - no effect - and then went in and took off the belt and tensioner and put them back on again but a little bit looser. So far so good , no more shrieking when cold just before shifting up to 2nd and 3rd.
The new tensioner was a lot stiffer than the old. BTW don't try to adjust the tensioner without lining up the marks , you will end up having to take everything off anyway when the belt jumps.
 
It's got cold again and this has re occured:bang:

Managed to get a recording of it:)

(Don't even think about trying to be a tw@t and tell me not to use my phone whilst driving. I started the recording on my drive and turned it off when I got back to my house after going round the block).

It's an MP3 file so will play with WMP, Itunes etc.

you can hear it briefly from about 16-30 seconds. Then hear it quite load from 33-36 seconds.

EDIT I can't attach the MP3. Hang on guys......
 
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Is the noise worse if you put on all the electrics while car is cold? That will load up the alternator and accessory belt and maybe make the noise louder.

If its a 16V and the cam belt is in doubt I would say get it done ASAP as a failure is VERY expensive. On the 8V its inconvenient unless you break down on the M-way without RAC cover.

It could be any of the tensioners or idlers and the water pump is also in the frame - when failing they are usually noiser when cold.

If you look closely at the accessory belt and you can see cracks across the grooves then its way past its use by date and should be swapped. Assume the cam belt will be in much the same state.
 
Check out the accessory belt. If its cracked across the ribbed side its due for replacing. The cam belt is probably going out along with it. Replace the idler wheels and tensioners and water pump.
 
I have a sound clip of my Punto 1.2 8v making this sound. When I got the car about 3 weeks ago, it was only making the sound on cold starts. In the past few days it has been making the sound in 5th Gear at 70mph or 5th Gear at 50mph. Basically any speed it likes.

Not being a Mechanic, If I'm right the Cam Belt is the one attached to the side of the Alternator! If so the sound does not come from there, its coming from within the Engine. When looking at the Engine its the left hand side of the engine making the sound.

Mate of mine has mentioned to me Fan belt or possibly a Thrust Bearing, whatever that is!

unfortunately I cannot upload the Sound Clip, if I can upload it anyone advise me as to how to do it?

Chris
 
The water pump is under the plastic cam belt cover at the left hand side of the engine (viewed from the front). Water pump bearings screech when they are packing up.

A whining whistle that goes up with engine speed could be broken teeth on the cam belt. The only way to confirm that is to remove the cam belt cover.

The water pump is annoying but unlikely to wreck the engine (at least in the short term).

If the cam belt is losing teeth, it could fail next time it's started. Inconvenient on an 8V. Very costly on a 16V.
 
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I can see a few possibilities:

*From cold, slipping alternator belt
*In particular gears, increasing with engine speed, not when stationary, gearbox
*In all gears, increasing with engine speed, but present on the over-run, rather like a Stuka on a bombing run, differential
*At any time, increases with engine speed, shot alternator bearings (can sound like a power station)
*At any time, increases with engine speed, cam tensioner

An engine stethescope is a good way of determining most of the causes. Very cheap from your local factor or Machine Mart.
 
When driving at say 50mph or 40mph or even 70mph when the sound is whining, when u dip the clutch it goes away but it may or may not reappear when bringing the clutch back up!

I have to say its very strange
 
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