• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Suddenly getting 10 degrees of KR

buickman104

buickman104

New member
I have a gen5 with 3.6" pulley and my own DHP tune. My mods include 3 inch catted down pipe, front power log, and 3 inch FWI (still on l67 throttlebody). Four days ago out of the blue my car started getting 10 degrees of KR when I went WOT. I noticed that when under load (not in neutral or park) when I give it above 50% throttle I get 10 degrees of KR. Before this started happening I would get blips of about 2 degrees at WOT with 16 degrees of timing.

I have checked the spark plugs and they are all fine. Oil has 1,500 miles on it and still amber. Fuel trims are good. Any other ideas?

I was thinking would it be possible that my Catalytic decided to fail? Just thought of that possibility today.
 


I bought an AEM wideband Kit. I guess I should make another thread as to installing it. Just strange that is suddenly happened. That's what makes me think it might be something mechanical.
 


Weather has stayed constant lately. Also finished the gas I had in the tank and tried some sunoco 94 octane. No difference.
 
My guess is your motor mount collapsed to the point of letting your DP smack your sway bar and you're getting false KR. Been there, done that
 
If you're pulling 10 degrees of timing you'll hear it knocking. It sounds like a misfire or little fire crackers going off under the hood.
 


gtpsleeper said:
does it creep up to 10 or does it just hit 10?
Click to expand...
It flashes like 6 degrees then 10 degrees of KR immediately.

OH4CompG said:
My guess is your motor mount collapsed to the point of letting your DP smack your sway bar and you're getting false KR. Been there, done that
Click to expand...
I thought about that too. Had my buddy move back and forth a few feet going from Drive to reverse. I could make out any excessive movement and both lower mounts have only about 6,000 miles on them.

I don't hear knocking, but i feel the motor bog down from pulling timing. Although I've kept my foot out of the car from fear of blowing the motor. So my driving has all been granny driving since that problem started.
 
All the same, jack the car up and see if your DP or power steering lines/sway bar have any marks on them from it hitting. Look close. Mine only had a 2mm mark on it but it was enough that when it shifted at WOT on mine there'd be like 11 degrees of flash KR on the shift
 
Interesting.... I too am having this issue. It just happened out of the blue as well. I replaced my engine mount a year or so ago but I guess it's possible it could have issues again. It could even be the trans mount. I've felt a dp hit the sway before after I put in headers. You could definitely feel it before i flipped my sway. It vibrated the floorboards terrible. I'm curious to see what you find out. I'm gonna give my mounts a once over when I get a chance.

Although my issue seems to happen if I get into any boost above 2psi instant kr out tha wazoooo!
 
SnowFlake said:
If you're pulling 10 degrees of timing you'll hear it knocking.
Click to expand...
Not necessarily. I've had a bearing going out and couldn't hear the 15 degrees from that. Sensors heard it.. I didn't.

Antonio, I believe it might have to do with the warm/cold/warm/cold etc. I'm seeing it too. Haven't had a chance to address it and .... I don't have a chipped piston. It's in the tune from what I can see.
 


Yeah cuz the other day, it wasn't much colder out, maybe a few degrees colder and understand WOT, I would be at 12.4 afr but .4 degrees of knock. And at 3/4 throttle I would be at 10.0 afr. I didn't understand it. The humidity was up like crazy though.
 
anyway we can get a scan of where the KR issue is at? or what fuel trims are?... etc...

kinda hard to diagnose this issue from the info here but going off of what is presented Im going with false knock somewhere....
 
You must log in or register to reply here.
Back
Top