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Registered
Join Date: Feb 2008
Location: Humble, TX
Posts: 119
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Timing belt I think is to tight
Just got everything done and took it for a test run really quick. After you get above 2k rpm the engine gets really loud and can feel vibrations but less then 2k/idle it sounds normal. I used the cricket to check the belt tension but it felt tight to me. How far you supposed to rock the cam back before checking the tension? Is all the slack supposed to be in the longest span of the belt?
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1984 944 NA 5spd |
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08-21-2008, 09:03 PM
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Nobody Special
Join Date: Jul 2003
Location: NorCal
Posts: 522
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Did you do the balance shaft belt also? Are you sure you got them registered correctly? They will vibrate something terrible above 3K if out of sync. Yes, the slack on the TB is on the longest span. I always turn a new TB two revolutions and recheck all my alignments. I've never been able to get comfortable with a Kriket and gave mine away.
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86 - 951 - Garrett dbb T3/T4R/Tial/Maxtronic -SOLD 91 - BMW 325 iX AWD, 5-spd Coupe, Lazur Blau Metallic-SOLD 86 - 951-K26/8, daily driver-SOLD 87 - 944S - Another daily driver-SOLD |
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08-21-2008, 09:44 PM
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Registered
Join Date: Feb 2008
Location: Humble, TX
Posts: 119
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My timing marks line up correctly. Sounds like they are out of sync. I know the balance belt is supposed to be lined up but I thought it was right.
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1984 944 NA 5spd |
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08-21-2008, 10:04 PM
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Automotive Necromancer
Join Date: Nov 2006
Location: Beantown, MA
Posts: 1,544
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too tight?
If the belt is too tight it will whine both at idle and at speed. It sounds more like you are off a tooth somewhere or off 180 on the balance shaft. Sometimes if the flywheel is locked in place during the procedure you have to release the lock to get that 1/2 tooth.
It is easy to get the balance shaft off 180 degrees. If the cam shaft was off the engine would not run well if at all. Try redoing the balance belt. The Kricket is not so bad, It is a lot better than nothing. I use mine as a sanity check and employ the twist like Chubby Checker.
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There may be nothing quite as expensive as a cheap Porsche: Ruby Red 84 928S : White 87 924s 2.5L NA (Blinky) M44/07-43H10676 spoiler delete - 046/2B - Belts 9/12, Clutch and OC seals 8/08 andd Red 94 Del Sol: Please put your Make, Model and Year in Sig. Try not to break more than you fix. |
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08-21-2008, 11:01 PM
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Back from Beyond
Join Date: Nov 2004
Location: Alberta, Canada
Posts: 2,697
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When timing balance belt:
Crank at TDC. Balance shaft keys facing up. Line up notches on sprockets with timing marks on timing cover - upper and lower. It really is that simple. But it's easily over-analyzed. Installing the tensioner can pull the shafts out of time so be aware of that. If anything it'll pull the top one ahead a tooth, IIRC.
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'88 944 Auto - project, kinda '87 944 Auto - died saving my wife '84 944 5SP - crushed under shop roof during snow storm All others GONE! |
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08-22-2008, 10:57 AM
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Registered
Join Date: Feb 2008
Location: Humble, TX
Posts: 119
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Both of my balance belt sprockets were out of alignment. I notice a little bit of a whine as the rpms go up now though.
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1984 944 NA 5spd |
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08-22-2008, 05:46 PM
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Nobody Special
Join Date: Jul 2003
Location: NorCal
Posts: 522
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Glad to hear you found the problem, it's easy to get the BS's out of sync. If the whine sounds like a supercharger your BS belt is still too tight. They fit pretty loose by most belt standards because there is no real load on them. Usually a TB won't whine if it's too tight though.
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86 - 951 - Garrett dbb T3/T4R/Tial/Maxtronic -SOLD 91 - BMW 325 iX AWD, 5-spd Coupe, Lazur Blau Metallic-SOLD 86 - 951-K26/8, daily driver-SOLD 87 - 944S - Another daily driver-SOLD |
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08-22-2008, 06:11 PM
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mined whined a little at first, but over 1000 miles has quieted down a lot, i guess it stretched.
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chance favors the prepared mind 1987 944 n/a 5spd. who remembers dial phones?. 'STOP FIXING THINGS ONE STEP BEFORE YOU BREAK SOMETHING ELSE" |
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08-25-2008, 12:53 PM
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Custom User Title
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I've gotten to like the whine - it tells me all is A-okay.
What's scary is when the timing belt slaps against the belt housing (on release of throttle) when it's too loose! I like whining a whole lot better.
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83 944 NA - Black on black 86 951 - Red - SOLD 7/21 16 Ford Expedition He who hesitates is lost. |
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08-25-2008, 04:44 PM
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1987 Porsche 944 2.5
My 951
My 83 NA
