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knock question

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scotty455

New member
ok im trying to narrow down some knock ive been getting lately even after all my mods gen v intake 180 etc. 3.6 pulley it will go up to about 1.6 then down to almost nothing then back up to about 2 then almost nothing. basically everyone is telling me it sounds like false knock and yes i swapped back to the stock 3.8 pulley and knock was still doing pretty much the same. By pretty much i mean being very random, not the same every time. i always run 93 octane. I replaced my dogbone mounts with intense polys. I changed my oil tonight and the downpipe doesnt have and dings or scuffs i can see from the sway bar (would there be any if it was hitting?) Lower mounts didnt look too bad. The only thing i can think of would be the transmission has been acting weird every so often when i take off from a stop it seems to jerk into gear and start going never does it any other time and only every 3-4 weeks maybe. Could the trans be giving the rear sensor false readings? My aeroforce gauge doesnt show it knock when it jerks and its just really random. Mainly when its on the highway especially uphill which i know puts a lot of load on it. In town driving it never gets past 1.2ish tops. Any thoughts if its false or if it could be real?
 


knock below 2-3k rpm's?

Your going to get a lot of speculation, but really we just need a scan of this, or who it was tuned by and what was done to the pcm so far.
 
There really isn't anything false about knock. Something causes the sensor to pick up noise and report it. Might be tune related say too much load and timing in one cell of the spark table, might be mechanical like an exhaust leak that the sensor can hear or a rattling bracket that is loose from some work. Could even be a bad knock sensor. Thing I'm getting at is..there's a reason the sensor is hearing something.
 
it usually knocks around 3,000 and up when it does. it was originally tuned by intense just a mail tune then i had it custom tuned by a guy in minneasota. MAF is brand new as of february/march. front knock sensor is newer than that. The rear one is factory im assuming. this is why i hate iowa since there is really no one a around here to help me look at it. Would the downpipe have marks on it of the sway bar was hitting it?
 
If anything gets hit enough..it'll have marks.

On that front sensor.. did you properly torque it to 14ft lbs? More or less and you will change the sensitivity.
 


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