buzz saw!!??
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Joined: Jan 2001
Posts: 527
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From: outerspace(maybe..pluto)?
buzz saw!!??
my freind has a 86 tpi trans am and when he comes up to a stop light theres a buzz saw sound coming from the engine compartment! help its annoying! actually sounds like a saw! cutting metal!
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1989 firebird formula
Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 and a 600 edlebrock manual choke.
Future mods performer rpm air gap intake (polished) comp roller cam, and way better headsa 400 defintely in the works!
[This message has been edited by burnoutrpm (edited January 28, 2001).]
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1989 firebird formula
Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 and a 600 edlebrock manual choke.
Future mods performer rpm air gap intake (polished) comp roller cam, and way better headsa 400 defintely in the works!
[This message has been edited by burnoutrpm (edited January 28, 2001).]
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Joined: Jan 2000
Posts: 19,659
Likes: 310
Burn,
That's fairly common, and is completely normal if it's coming from the transmission. I'll bet the noise goes away if he raises the idle just a little bit with the accelerator pedal.
There was a TSB from GM on this phenomenon, and while it can be unnerving and annoying, it is not a problem. The pressure regulator/relief valve in the transmission is chattering open and closed when the engine is idling in gear because the engine and transmission input shaft are turning just fast enough to make almost enough oil pressure in the trans. A few more RPMs and the noise goes away.
Ask you friend if he/she has ever replaced the PROM in the car. GM had another TSB regarding faulty programming, and there was a re-written PROM released to solve some of the problems. One of the changes is an increased target idle, making the transmission noise disappear and improving throttle response. The replacement PROM also improved the torque converter lockup points, increases mid-range fuel enrichment, tolerates a wider range of sensor inputs before setting a trouble light, and has an improved spark curve.
The replacement for my '86 TA/TPI PROM was $63.00 from the dealer, and it made the car act totally different from the doggy I was accustomed to driving
. Well worth the cost, in my opinion!
The part numbers for the replacement PROMs can be found at MikeInAZ's site, the 3rd°. Enter the site and go to the "Tips" section, then "Bugged PROM".
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Later,
Vader
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"Make Me Bad..."
Adobe Acrobat Reader 4.0
KaleCo Auto Parts
[This message has been edited by Vader (edited January 28, 2001).]
That's fairly common, and is completely normal if it's coming from the transmission. I'll bet the noise goes away if he raises the idle just a little bit with the accelerator pedal.
There was a TSB from GM on this phenomenon, and while it can be unnerving and annoying, it is not a problem. The pressure regulator/relief valve in the transmission is chattering open and closed when the engine is idling in gear because the engine and transmission input shaft are turning just fast enough to make almost enough oil pressure in the trans. A few more RPMs and the noise goes away.
Ask you friend if he/she has ever replaced the PROM in the car. GM had another TSB regarding faulty programming, and there was a re-written PROM released to solve some of the problems. One of the changes is an increased target idle, making the transmission noise disappear and improving throttle response. The replacement PROM also improved the torque converter lockup points, increases mid-range fuel enrichment, tolerates a wider range of sensor inputs before setting a trouble light, and has an improved spark curve.
The replacement for my '86 TA/TPI PROM was $63.00 from the dealer, and it made the car act totally different from the doggy I was accustomed to driving
. Well worth the cost, in my opinion!The part numbers for the replacement PROMs can be found at MikeInAZ's site, the 3rd°. Enter the site and go to the "Tips" section, then "Bugged PROM".
------------------
Later,
Vader
------------------
"Make Me Bad..."
Adobe Acrobat Reader 4.0
KaleCo Auto Parts
[This message has been edited by Vader (edited January 28, 2001).]
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