Causes of knock...Should i worry?
#1
Causes of knock...Should i worry?
Hey guys i bought my evo ix mr about 4 months ago and im starting to detect knock recently. I have read that it could be anything from exhaust noise to a bad knock sensor to even loud cams especially the kelfords which is what the car has.. It seems to only happen when i do a 3rd gear pull but it does not always happen. The check engine light will flash about 4-5 times. I can tell the car is tuned rich and i am having it retuned next week to be safe but i was just wondering what are the major causes of knock and should i be worried with it blinking that many times. Sorry if its a noob question. Also seems worse when its colder outside.
Mods are kelfords 272,injen uicp,licp,3"exhaust with test pipe,act clutch,lightweight flywheel,255walbro,1250cc fic injectors.. Its currently tuned at 18psi.
any help is appreciated.
Mods are kelfords 272,injen uicp,licp,3"exhaust with test pipe,act clutch,lightweight flywheel,255walbro,1250cc fic injectors.. Its currently tuned at 18psi.
any help is appreciated.
#2
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bad/ low octane gas, excessive cylinder pressure, too much timing (ie bad tune). It can be phantom knock, from the cams or the lightened flywheel/clutch combo. Your tuner should be able the check for it. Also, I shouldn't get worse with cold weather. Good luck
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I wouldn't go that far. But a good way to check is to do a 4th (1:1) gear WOT pull and log. That goes through most of the load range (which encompasses 3rd gear load). If you're getting knock there, you let out. If not, it may be the frequency of the vibrations in 3rd. Also, is the SES blinking fast or slow? Some tuners leave 1-2 counts in the tune (sacrifice for more power). If that's the case, make sure the next person to tune pulls timing there. There's no point in that methodology for a couple hp.
#6
I wouldn't go that far. But a good way to check is to do a 4th (1:1) gear WOT pull and log. That goes through most of the load range (which encompasses 3rd gear load). If you're getting knock there, you let out. If not, it may be the frequency of the vibrations in 3rd. Also, is the SES blinking fast or slow? Some tuners leave 1-2 counts in the tune (sacrifice for more power). If that's the case, make sure the next person to tune pulls timing there. There's no point in that methodology for a couple hp.
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#13
I wouldn't go that far. But a good way to check is to do a 4th (1:1) gear WOT pull and log. That goes through most of the load range (which encompasses 3rd gear load). If you're getting knock there, you let out. If not, it may be the frequency of the vibrations in 3rd. Also, is the SES blinking fast or slow? Some tuners leave 1-2 counts in the tune (sacrifice for more power). If that's the case, make sure the next person to tune pulls timing there. There's no point in that methodology for a couple hp.
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This pretty much points to phantom knock from vibration. That's why in colder weather (less expansion) things rattle more, hence showing the ecu more knock. I had a similar issue where one moment I'd get the knock light in 4th, then couldn't replicate it. Sometimes i would randomly get "knock" under light acceleration 2nd.
I wouldn't be so worried as to not drive it, but I would have it double checked just in case. Good luck
I wouldn't be so worried as to not drive it, but I would have it double checked just in case. Good luck
#15
This pretty much points to phantom knock from vibration. That's why in colder weather (less expansion) things rattle more, hence showing the ecu more knock. I had a similar issue where one moment I'd get the knock light in 4th, then couldn't replicate it. Sometimes i would randomly get "knock" under light acceleration 2nd.
I wouldn't be so worried as to not drive it, but I would have it double checked just in case. Good luck
I wouldn't be so worried as to not drive it, but I would have it double checked just in case. Good luck