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mattaebersold · Posted: Fri Jul 26, 2019 2:32 am Post subject: 931 engine squeaks

I recorded a video of my 931 engine running (trying to haha). Like the video states, I have another 931 engine out of the car now that I'm rebuilding, which is going well. I'm asking about these squeaks for a couple reasons:

1. I would like to know the source of the squeaking, since I'll be reusing some external engine components after my rebuild is done (turbo, alternator, AC, etc)

2. Have any of you experienced squeaks like this? Curious if the cause is turbo-specific or just in general?

Thoughts are:
- turbo?
- bearings in pulleys?

https://www.youtube.com/watch?v=FK7prhFEbFI&feature=youtu.be
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1980 931
1991 Japanese Classic Mini
2000 740i
2006 530xi Wagon

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2596 Location: MI

Spray some water, or better yet belt dressing, on the alternator belt while its running and see if it goes away..
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80 Turbo - Slightly Modified

Dutch924-racer · Joined: 23 Jul 2007 Posts: 1077 Location: The Netherlands

do a short test without the v-belt and you ensure it is not the alternator or the waterpump.

If the sound has gone, then it is or your alternator or your waterpump

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937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller

morghen · Joined: 21 Jan 2005 Posts: 8879 Location: Romania

Sounds like waterpump or alternator bearings...but maybe you overtightened the timing belt also?
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mattaebersold · Posted: Sat Jul 27, 2019 2:29 am Post subject:

Thanks all! I'll try those things to see if the sound is gone
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PARTSTASH: www.partstash.com

1980 931
1991 Japanese Classic Mini
2000 740i
2006 530xi Wagon

Johann · Joined: 07 Aug 2016 Posts: 240 Location: Netherlands

This sounds like a waterpump or tensioner pulley.