2002 I35 Spark Knock

[gkellum]

Searched for previous post!!!

Bought my 2002 I35 about 18 mos ago with 47000 miles. Noticed it had a little spark knock when under load conditions. Car now has 76000 miles and the spark knock is terrible and it seems very sluggish / hesitant to get upto speed.. Always use 93 Octane!! There are no codes displayed. Help!!

Has anyone had / and or resolved this problem?

[qship96]

Sure it is not a loose exhaust heat shield rattling ?

Have you checked codes to rule out bad knock sensors which DO NOT illuminate the "check engine light"?

Might want to have tech check/adjust engine timing and do a once over on basics{vacuum leaks, disconnected connectors, sparkplug condition,etc}

[gkellum]

Thanks Qship96, I'll look into it!!

[Q451990]

Have you checked codes to rule out bad knock sensors which DO NOT illuminate the "check engine light"?

Bet the OBDII ECU in an '02 does. Not sure though...

I would suspect carbon fouling or a clogged EGR passage - but that's just a wild guess.

Heath

[qship96]

OBD2 in my 1996Q does NOT illuminate check engine lamp for knock sensor codes pretty sure later{97-06Q} dont either.Easy enough to rule out by using a generic obd2 code reader either way.

[maxnix]

With no maintenance history provided (OCI, fuel filter ?), we are stumbling in the dark somewhat.

[gkellum]

Thanks for all the input.... I have done nothing to this car other than an alternator/ water pump and a battery. I am getting the code scanner run again tomorrow and hopefully will know more then.

[fixer]

i have seen a lot of maf sensors go bad on your type of veh. ck with a scan tool and look at the alpha on leaf and rt bank. it shoud be around 95 - 110%. if you have pinging it would usually be from alpha being too high. if you dont have any vacuum leaks, i would ck the Mass air flow sensor/meter.

[gkellum]

I had the scan tool hooked up again today... Nothing?? I also cleaned the MAF with electronics cleaner. Not any better.