Im looking to buy an ef with a 1st gen b16 swap, but the only issue the motor seems to have is the owner says there is some sort of "phantom knock" where a sensor thinks the motor is knocking, therefor retarding the timing slightly? (This is how he described it to me)

Anyone ever heard of this?
Should I stay away from this?
What causes this?

Any insight would be appreciated and could save me alot of headaches in the future.

thanks, and peace

Chuck

 

bump, any help?

 

The b16a utilizes a knock sensor that retards timing if it senses knock. I would be skeptical but would go and see the car and drive it and see if I could hear the knock. Just give the car a thorough look over.

 

maybe he meant he didn't install it like the other guy said go and see it drive and make up your mind from there

 

knock sensor measures detonation. if it throws a knock sensor code it might now be hooked up. i dont see how the owner could know that the motor is sensing a knock that really isnt there and how can he tell the timing is being retarded. sounds fishy.

 

the only context ive heard phantom knock in is with dsm guys. usually its reserved for people with turbo setups that arent managed as well as they should be though. ive never heard of a honda with "phantom knock" that was N/A though.

the dsm guys call it phantom knock because the circumstances for which it occurs seem to be difficult to reproduce predictably. they cant pinpoint it to one simple thing. they replace the knock sensor and it still occurs. they install better fuel management and it still occurs once in a while..etc.... some of those guys go round and round trying to find it and never do. most issues i have heard end up being bad tuning as a major contributor to it. i guess the point is there is no silver bullet when it comes to "phantom knock".

i am with 91civicLX though. they are probably either runing with a knock sensor disconnected or just going bad. and ask him why he thinks its "phantom knock". high compression and low octane gas can produce just plain knock, and from what i understand jdm ecu's are tuned for higher octane, so if he is running 85 octane with a jdm ecu that is tuned for 91 or 93 or higher, then that could be the issue as well.

if it were me though, i would low ball the guy for the car stating the "phantom knock" issue as a reason you are hesitent to pay more for the car... and then try and figure it out.. but thats just me. good luck.

 

thanks for the help guys, I'll give him a call tomorrow and see if he can explain himself a little better.