Does my car sound funny to you all? I just finished doing a timing and balance belt replacement and I started it up for the first time since the replacement. I can’t remember if it sounded like this before. I shut it off immediately and then checked the alignment marks of all the belts. They all are aligned as they should be. Any ideas?
Link to sound: (
Does my car sound funny?
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rustybolts924s
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Porsche 924S '87
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Tom
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Yes, it sounds funny. Make sure you tensioned the balance shaft eccentric in the correct directions (if you tighten it the wrong way, it can rub on the cover). More likely, the balance shaft belt is just too tight. They make a whirring sound like that above about 3.5 on the factory tool, and gets louder as it gets tighter. I'd guestimate yours is 4.5 to 5. 
How did you set the tension?
How did you set the tension?-
rustybolts924s
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I don’t have a factory tool so I did it by eye by deflection. I also used the carpokes 3d printed tools. I’ll loosen it up a bit and see what happens. What do you think about the ticking noise?
Porsche 924S '87
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Tom
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I didn't really hear ticking? I heard the belt whine kind of pulsing, but that's pretty normal. If you rev it, it should turn into a more steady whir. Although I didn't hear it, it's not uncommon for lifters to tick a little after extended down time, if it took a week or three to do the belts...?
Edit: listening again, I think I hear what you mean about the ticking. What happens when you rev? Sounds more like exhaust than lifters to me -- at least based on compressed internet audio playing on cheap computer speakers... I'd start with the balance shaft belt and see how it sounds without the whir.
Edit: listening again, I think I hear what you mean about the ticking. What happens when you rev? Sounds more like exhaust than lifters to me -- at least based on compressed internet audio playing on cheap computer speakers... I'd start with the balance shaft belt and see how it sounds without the whir.
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rustybolts924s
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I loosened the balance belt and went for a ride. It sounds a lot better. The ticking noise can now only be heard when the hood is popped. It does get louder with more revs but nothing as loud as before. Thank you for the suggestion for loosening the belt, it definitely worked
Porsche 924S '87
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Tom
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That's great. The balance shaft belt tension is not intuitive at all. At the proper tension, most rational mechanics think it's way too floppy.