Hello fellow f-body owners. I am requesting some help on this noise. My 89 formula 350 makes a rattling noise in the engine at higher rpm usually when it shifts into second gear on hard (floored) acceleration. I do have an aggressive chip with a new transmission, MSD ignition, and even a cooler stat. I was wondering if this could be agressive spark knock or maybe something else. Has anyone had this issue with theirs at one time or other? Any help would be appreciated. Trying to get to the track to run some times. This could hurt me. Oh, by the way, when chip was burned (pcmforless), I opted for them to desensitize the knock sensor.
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89 Firebird formula 350--95k on it, MSD ignition, full catback exhaust (flowmaster) 160 degree stat, custom chip from pcmforless.com, TPIS air filter, TPIS air foil, TPIS MAT relocation kit, built 700R4 with stage 2 shift kit and corvette servo.
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sounds to me like it's either something tune related or you have a loose rocker and it's tapping when you hit the upper rpms. when you say higher rpm.. how high of rpm is that? does it start making the noise at 3k? 4k? 5k?87 GTA: it's winter time, all tore apart
ConElite: "Im 22, have had my TA since I was 21."
"I wont lie, I have a heavy foot, but at the same time I know when its the safest to ring out a gear or 2."
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It seems to only do it after the car hits second gear on hard acceleration. So, maybe around 3500 rpm and up. Doesn't do it at idle or reving it up at stand still. The engine is pretty much tap free. Seems to be more under a load.89 Firebird formula 350--95k on it, MSD ignition, full catback exhaust (flowmaster) 160 degree stat, custom chip from pcmforless.com, TPIS air filter, TPIS air foil, TPIS MAT relocation kit, built 700R4 with stage 2 shift kit and corvette servo.Comment
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are you sure it's coming from the motor and not the tranny? do you feel any vibration at all when it makes the noise? sounds to me like it could be an internal tranny issue or a torque converter problem. the main reason i think this is because if it was a motor issue, it would most likely do it in all gears including neutral or park. how high did you rev the car in neutral/park to see if it made the noise? over 3500 rpm?87 GTA: it's winter time, all tore apart
ConElite: "Im 22, have had my TA since I was 21."
"I wont lie, I have a heavy foot, but at the same time I know when its the safest to ring out a gear or 2."Comment
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i actually figures it out. My timing was way to advanced. It was set at 12* tdc and with my agressive chip I am sure it was running deeper that that at full throttle under a load. Set the timing to 6* (recommended stock setting) and let the chip do the rest. The car actually idles better and all drivetrain noise is gone. Especially at high rpm. The power is even better and reaches 100mph faster than before. Thanks for all help.89 Firebird formula 350--95k on it, MSD ignition, full catback exhaust (flowmaster) 160 degree stat, custom chip from pcmforless.com, TPIS air filter, TPIS air foil, TPIS MAT relocation kit, built 700R4 with stage 2 shift kit and corvette servo.Comment
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if ur running 87 bump it up to 89 ir 91/93 fuel that way u can run a lil more agressive timing. what i use to do was on a tank full of 87, advance the timing till it started to ping, back it off 2* degrees and then run on 89 and it was a quick way for some more power. not to mention i somehow got an extra 2mpg
2009 Honda Civic EX- the daily beater
old toys - 1983 trans am, 1988 trans am, 1986 IROC-Z, 2002 Ram Off-Road, 1984 K10, 1988 Mustang GT, 2006 Silverado 2500HDComment
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