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Matt, Mechanical Engineer
Category: Car
Satisfied Customers: 22932
Experience:  BEng hons Mech engineering, in auto industry 22 years
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I have 56 plate Alfa Romeo gt 1.9 jdtm and I have a strange

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Hi I have 56 plate Alfa Romeo gt 1.9 jdtm and I have a strange engine whine when it starts to get hot. From start up the engine sound is what I would call normal after 3 to 4 miles the whine starts. I got a local garage to drop the aux belt and check the pullies tensioner etc. Nothing wrong. I do notice that when I switch the car off there is a whine for about 1 to 2 seconds which would indicate something turns after switch off. It's not the fan. Could it possibly be the Alternater freewheel clutch of the water pump the cam belt water pump and tensioner were changed 7000 miles ago as was the aux belt and tensioner. It had a new turbo, egr delete and swirl flap delete within the last 200 miles the noise was there before that work was done.


1st try turning every pulley and ancillary ( power steering pump , alternator etc) by hand. All should turn easily (with the exception of the AC pump) with no grittyness or wobbly pulleys- If you do find a sticky pump / alternator then it should be replaced or repaired

If the engine is stone cold you can briefly run it with no belts to see if the noise changes or has gone away, this will help show if an ancillary is the issue


I see that you've rated my answer negatively

how can I help further?

please note that the process is meant to be a back and forth between expert and customer to solve your issue

Customer: replied 1 year ago.
I have rated this as port because I stated in my original question that I had already got a local garage to drop the aux belt and check all the pullies and tensioner. You simply told me to do what has already been done!


ok so is the whine there with the belt removed and running a stone cold engine?

if its still there then it could be a vacuum leak on the inlet as these can also produce a whistle or whine

The best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane around each joint in turn. If the engine rev's up you've found your leak.

Now you might think that spraying lighter gas around a hot engine isn’t wise, however the flash /ignition point of gas is about 400°C so you need a naked flame or spark to set it off and I’ve used this method for many years without incident.

Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements.

Customer: replied 1 year ago.
There is no whine when the car is cold it only starts to whine after 3 to 4 miles as the car warms up it is more pronounced on over run. When in 6 th gear doing about 70 no whine can be heard.

Ok thanks for the extra info

so if the noise only starts once things are warm then its possibly a vacuum leak as they are strongly effected by engine and ambient temperature as inlet system parts expand and can then move away from each other

please check it out and let me know what you find

Matt and 2 other Car Specialists are ready to help you
Customer: replied 1 year ago.
I've decided to take the car to an indendant Alfa specialist who did all the mods I will pass on what you advise. I'm sorry it was a shaky start I am happy with your response.