Getting A Lot of KR and Bad MPG [Archive] - GrandAmGT.com Forum

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timberwoof
04-20-2009, 04:14 PM
Just like the title says, I've been getting quite a bit of KR lately and can hear it. The gas mileage has also been going down hill fairly quickly.

I'm thinking about doing the regular tune up. Plugs, wires, O2s, Fuel filter, and injector cleaner.

What else do you guys think I could do to help?

GrandAmMe
04-20-2009, 04:41 PM
im so sorry but what does KR stand for?

KhellendrosxS
04-20-2009, 04:52 PM
KR = Knock Retard.

What are you scanning with? If you can actually hear the knocking then Im going to say your motor is probably going to be on its way out soon. Most of the time the PCM only has to retard a few degrees. By the time you can actually start hearing it and the PCM cant recover its not good.

Id also check the connection on your knock sensor just to make sure it isnt sending bad data to the PCM.

zukiracer19
04-20-2009, 05:08 PM
KR = Knock Retard.

What are you scanning with? If you can actually hear the knocking then Im going to say your motor is probably going to be on its way out soon. Most of the time the PCM only has to retard a few degrees. By the time you can actually start hearing it and the PCM cant recover its not good.

Id also check the connection on your knock sensor just to make sure it isnt sending bad data to the PCM.


how come my car knocks for like 1st min or less on startup until it warms up?? is that normal? i know my friends new silverado does it too

Nick-G
04-20-2009, 05:17 PM
how come my car knocks for like 1st min or less on startup until it warms up?? is that normal? i know my friends new silverado does it too

Piston slap.

zukiracer19
04-20-2009, 05:23 PM
is that ok on cold start? once it warms up after like 30 sec to a min it stops

Nick-G
04-20-2009, 05:35 PM
Some piston slap is pretty normal when the engine is cold.

It stops after a few minutes because as the engine warms the piston will expand and fit tighter in the cylinder.

BOOTMASTER
04-20-2009, 06:23 PM
run a scan tool on it or have it scanned at a parts store.... then hope you motor isn't going out... then check the knock sensor, then do your tune-up and hope it helps... while your at it, cut open your oil filter and check for metal in there, if there is, debate a new motor or new car...

zukiracer19
04-20-2009, 06:44 PM
plugs can give KR pretty quick if they are fouled out.. not sure with stock motor though lol

timberwoof
04-20-2009, 08:18 PM
Ok, I'm guessing KR may not be the right term I'm looking for then.

I'm talking about the rattle at half to full throttle... You know sounds like a diesel...

ga2001gt532
04-20-2009, 08:37 PM
exhaust could be loose maybe, or is it somewhere in the motor.

timberwoof
04-20-2009, 08:44 PM
I'm guessing its in the motor, because it kinda sounds like its a diesel and only does it only half to heavy throttle.