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View Full Version : Random knock at cruising speeds


Kevin 1G Drummer
09-13-2009, 07:44 AM
This seems to be a completely random thing, but every now and then my car will start knocking and pulling timing under light load/highway speed cruising. I have my DSMlink setup so that the check engine light comes on for anything over 3 counts of knock, but I don't have a laptop so I can't log it when it's happening but I can feel that it pulls timing. As soon as I completely let off the throttle and decel starts it goes away. After that, sometimes it stops, and sometimes it comes back right away so I have to let off the throttle again. Sometimes it's fine for a few seconds/minutes, then it comes back again.

I was thinking it could possibly be a faulty knock sensor, but I don't really have any idea.

123abc
09-13-2009, 08:12 AM
This seems to be a completely random thing, but every now and then my car will start knocking and pulling timing under light load/highway speed cruising. I have my DSMlink setup so that the check engine light comes on for anything over 3 counts of knock, but I don't have a laptop so I can't log it when it's happening but I can feel that it pulls timing. As soon as I completely let off the throttle and decel starts it goes away. After that, sometimes it stops, and sometimes it comes back right away so I have to let off the throttle again. Sometimes it's fine for a few seconds/minutes, then it comes back again.

I was thinking it could possibly be a faulty knock sensor, but I don't really have any idea.


Mine has always done that. Mine also seems to pick up certain exhaust tones too because it will pull timing at weird times when I know I'm not knocking and Im not even in boost. But when I do a full pull I get no knock at all.

munchgsx
09-13-2009, 09:47 AM
Alot of peoples cars do that mine included. I've never been able to tune it out. My sulution was to make the knock sensor less sensitive.

However I have never seen 3 counts so I would start with a fresh knock sensor first.

turbotalon1g
09-13-2009, 10:08 AM
I was gonna say the same thing, new knock sensor.
Is this a new thing or just always done it? If i remember correctly my car did it and when I replaced the knock sensor it pretty much went away but this motor is noisy

Kevin 1G Drummer
09-13-2009, 09:51 PM
It has been doing it on and off since about the middle of last winter. Seems like it will happen intermittently for a couple weeks, then not happen at all for a month or two, then it comes back intermittently again. Last night on my way to work it did it probably 8 or 9 times in a row over the span of about 3 minutes, but then on the way home it didn't happen at all. I will try replacing the knock sensor and see what happens.

FattyBoomBatty
09-13-2009, 10:33 PM
get a chevy knock sensor like mine, it doesn't really register knock at all, haha.

twack
09-13-2009, 10:58 PM
fatty tell me more about using that chevy unit. is it a starquest thing or dsms to.

but any how if you got dsm link just turn off the knock sensor till like 3500 and under 50% i know thats a bandaid but it works