fiat uno 'screaming' in gears 1-3 - melatonin
Hi all,

I've just got myself a 93 K Fiat Uno 1 litre Start (FIRE) and while it runs great generally, it makes a concerning screaming type noise when revved hard in 1st, 2nd and third gear, and occasionally 4th if pushed *really* hard. Although a novice I'm pretty sure it's not the timing belt slipping because the noise isn't as loud as that, nor as prolonged.

I'm an engine newbie so I have no idea what I'm looking for, although I have noticed upon inspection of the engine compartment that the small pipe that leads from the air filter to the exhaust (i think) is not correctly secured - it's obvious there's an imperial clip missing, and the top of the pipe doesn't properly surround the lip of the whole on the bottom of the air filter housing.

I've got my Haynes manual at the ready, and very little cash (!) - it's my first motor and I'm off to university in 6 weeks, so please don't hit me with terrible news!

Thanks in advance for any advice.
fiat uno 'screaming' in gears 1-3 - Another John H
The pipe you describe provides hot air to warm up the throttle body to prevent "carburettor icing" in colder weather (even though yours is SPI - it's doing what a carb would do in much the same place).

This pipe can rattle and make some rather odd noises.
If it's secured in the same fashion as my little FIAT (same engine), unclip the front of the airbox at either side, and also the spring clip down by the pipe - you should then see the filter, and be able to lift out the pipe from below:
IME it's just jammed between the airbox and the exhaust.

It's probably worth taking it to your local car spares shop and getting a new piece cut to fit in tightly.

On mine the airbox had lost a little rubber foot - so the whole lot was rattling about, which added to the unholy row it was making.


John H
fiat uno 'screaming' in gears 1-3 - melatonin
hmm if it's a simple as that then I'll be very happy! :)
fiat uno 'screaming' in gears 1-3 - David_S
Is it a scream or a high speed rattle ?

If the later then get the pipe sorted as mentioned by anotherJohnH

If it is more of a scream I would look at:
1: Alternator belt for signs of slipping or hardness and also check alternator bearings.
2: Timing belt tensioner as bearing may be shot.
3: Water Pump this is also driven by Timing belt.
4: Inside of timing cover incase belt/pulley has been in contact
5: Camshaft bearings

If you can isolate area noise comes and eliminate items in that vicinity.
Easier said than done, I know from experiance

Do you know when the timing belt and pully were last changed
if not you realy should change them anyway it is not a difficult job on the fire engine access is good as are haynes instructions.

fiat uno 'screaming' in gears 1-3 - melatonin
It's more of a scream - the sound is constant and not 'rattly', at least in the way i would consider rattly.

Great advice, I'll see what I can manage on my own, and I'll take it to a local garage to make sure.

I can't say from the documents if or when the timing belt was changed. The car's got 68k on the clock so it's possible it hasn't been changed (the interval is 60k for timing belt renewal).
fiat uno 'screaming' in gears 1-3 - Malcolm_L
Noises are a subjective thing at best - It's not the timing belt cos if that slipped your engine would stop!

More likely to be a slack accessory belt - check all the belts, at the middle point of the longest run, you should not be able to move the belt more than about 15mm in either direction.

Generally, if it feels slack adjust so the slackness goes - don't overtighten as this can cause bearings to fail.

Let us know
fiat uno 'screaming' in gears 1-3 - Vagelis
To my opinion, two possible sources for the noise:

1. Alternator belt not tensioned correctly (mentioned by others too).

2. Gone / low-oil / oil-empty gearbox. For a city-car, 1st, 2nd and 3rd gears are the first to go. Check the gearbox oil level. Better, flush it and put some new oil. Will also greatly help with gear-changing. Older Fiats are notorious for their gearboxes.

fiat uno 'screaming' in gears 1-3 - melatonin
I'll have the garage check this as I don't have ramps to get the car up. Thanks very much for the advice.
fiat uno 'screaming' in gears 1-3 - melatonin
I took it to a garage and it turns out that the water pump pulley is dry and needs replaced, which will cost a mere £30 (thankfully it's not nearly as horrifying as I had secretly expected)

Thanks everyone for you input.
fiat uno 'screaming' in gears 1-3 - Another John H
Get him to change the cam belt while it's off to do the pump.
It won't kill this engine* if it breaks, but it'll save you a walk..

*assuming it is a FIRE engine

fiat uno 'screaming' in gears 1-3 - melatonin
Looking at the belt, i think it was replaced at 60k miles, although i cannot be sure. I'll make sure he checks it and if need be replaces it.

Hehe.. great news too.. i went to a local breaker's yard today and found about £150 worth of parts on an old Uno for nothing (mainly cosmetics that needed replacing or fitting, like the cap for the screenwash bottle, the wiper blades [nice new bosch ones, too!], the front right headlamp assembly, the rear view mirror [i had been using a shoddy suction one just to keep within the law], the Fiat badge [!] and a spare wheel...) and all for £10.

Really, really satisfying.
fiat uno 'screaming' in gears 1-3 - Chris M
That's one of the benefits of running an older car. There are plenty of Unos at breakers and you're doing your bit by recycling.

Chris M


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