When I start the engine from cold, the engine sounds a lot like its supercharged. A belt type "wwwrrrrr" sound. I'v already done the air pump bypass, so I'm not entirely sure what it could be. It goes away when the engine warms up. Any ideas? Its an 07 4.7 4x4. Thanks for the help! :frusty:
4.7 sounds like supercharger on cold start. Not the air pump
- Thread starter bubbazr2
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Hmmm.. Sounds exactly like this. Must be the alternator :shrug:
https://www.youtube.com/watch?v=SpQ6XI8e0LQ
https://www.youtube.com/watch?v=SpQ6XI8e0LQ
AuSeeker
Elite Member
Get yourself a mechanic's stethoscope and pinpoint where the sound is coming from, just be very careful not to stick it into any moving parts, you can get them at any auto parts store for around $7 to $20 and very good ones can go upwards to more then $100, but the basic less expensive ones work well enough and you'll be amazed at how it sounds up close and personal when you actually pinpoint where the sound is coming from, and if it is your alternator you'll know once you stick the probe on it.
Just don't confuse normal engine and components sounds from abnormal ones, you will be amazed at all the different sounds that make up the normal sound of your engine running when you isolate each of the sounds with the stethoscope.
Just don't confuse normal engine and components sounds from abnormal ones, you will be amazed at all the different sounds that make up the normal sound of your engine running when you isolate each of the sounds with the stethoscope.
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