My dashHawk is telling me that my Jeep has Knock Retard.. I guess this is the PCM's response to detonation? My question is, how do I get rid of it. Doesn't the PCM decrease ignition timimg as a safegaurd to prevent further detonation??

Can I reset the PCM by disconnecting the battery and hope this goes away?

Thanks in advanced.

I believe it's more essential to find out why you are getting knock retard (decrease in timing). It's normally caused by bad gas/low octane, high temperature, and sometimes even rattle in your engine bay or drive train, etc. Only way to get rid of KR without actually fixing the cause is through custom programming (not recommended since you could damage your engine from too much timing) or perhaps get rid of the knock sensor.

I had tons of KR on my auto C5 due to aggressive PCM programming. Made the car feel like honda when it happened and hated it. Mixed that in with auto tranny and you got a mushy ride. Which reminds me of sluggish tranny issues reported by many folks here. Could this be result of KR - preventing downshift?

Thanks for the reply. Looks like the knock retard went away. Not sure why timing was decreased on the way to work this morning since I am using the same gas, and I don't think my engine was running hot. Anyways, I guess I should monitor this for a few..

catchy title.......

catchy title.......


Yes it is. In my personal experience I've noticed that most times they just stand at the door for hours and some do the complete opposite and yell at it. :eek:

Thanks for the reply. Looks like the knock retard went away. Not sure why timing was decreased on the way to work this morning since I am using the same gas, and I don't think my engine was running hot. Anyways, I guess I should monitor this for a few..
Just a thought but, you may not be using the same gas, I think right about now, companies are rolling out there summer blends.

Thanks for the reply. Looks like the knock retard went away. Not sure why timing was decreased on the way to work this morning since I am using the same gas, and I don't think my engine was running hot. Anyways, I guess I should monitor this for a few..

The same thing is happening to me. One day the Jeep will run like a bat-out-of-hell, and the next it won't get out of it's way. I may order the Dashhawk for the sole purpose of monitoring the knock sensors.

The same thing is happening to me. One day the Jeep will run like a bat-out-of-hell, and the next it won't get out of it's way. I may order the Dashhawk for the sole purpose of monitoring the knock sensors.

^^^^Exactly^^^^

Yes it is. In my personal experience I've noticed that most times they just stand at the door for hours and some do the complete opposite and yell at it. :eek:


I actually felt like a retard for not initially knowing what a knock retard was. Thaks for the clarificarion Grip :D

My dashHawk is telling me that my Jeep has Knock Retard.. I guess this is the PCM's response to detonation? My question is, how do I get rid of it. Doesn't the PCM decrease ignition timimg as a safegaurd to prevent further detonation??

Can I reset the PCM by disconnecting the battery and hope this goes away?

Thanks in advanced.

Change the PCV valve.

From my experience, diagnosing KR can be a frustrating experience. Aside from using diff gas, I would check the less obvious - is there any obvious rattles in the engine bay or drive train that would rattle under WOT? Some have mentioned putting a filter in the pcv to remove oil before intake manifold to help.

Change the PCV valve.


Can you elaborate, I don't see the connection?

Can you elaborate, I don't see the connection?

Have you checked your manifold to see if the PCV valve is working properly? Is the manifold oil soaked?

Oil in the intake track will cause detonation.

Check the internet for oil seperators or oil catch cans.