I have a 1997 318I the car runs fine when its cold but after its warm and you shut it off then restart it it runs real rough and makes a squealing noise like a vaccum leak but cant find anything? any suggestions?

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Try taking off the belt and see if it still squeals on a hot restart. Sounds like one of the pulleys may be seizing like the air compressor. Does it have with the AC on and off? If you feel it's a vacuum leak try spraying carb spark around the intake and see if the rpm picks up. Please be careful not to start a fire.

- Kerry