2001 jeep renagade

Do you drive your engine ultra-conservatively? If so, it could be full of carbon (a common source of pinging) which needs to be removed. The carbon continues to glow after the combustion stroke so during the early part of the next compression stroke, the glowing carbon ignites the air-fuel mixture prematurely. If you think you might have been driving that conservatively, spend a few days driving it ultra-aggressively by revving to high rpms under wide-open throttle as much as possible to blow the carbon out. Yes this is a legitimate technique that I didn't just make up. There's another way which involves SLOWLY trickling 16 ounces of water into the air intake system as the engine runs to scavenge the carbon deposits out... which is a highly effective method so long as you don't pour the water in faster than a slow-(SLOW) trickle. I take a few minutes to pour in 16 ounces... which leaves the combustion chambers sparkling clean, really... without any damage so long as you take your time as described. :)

Jerry

bigblack wrote:

Thanks heaps for the reply. but i never drive conservatively, could it possibly be thing els? do i take the tube off between the air cleaner and the thotle body(air intake) to trickle the waterto clean the crbon?

There's another way which involves SLOWLY trickling 16

I had heard once that if one had pinging or if higher octane fuels were not available, a few moth balls (nitrobenzene) could be added when re-filling the tank.

I told this to may late step-father who loved his old, (pinging) 2 dr Mercedes. He had such good luck that afterwards, that for 20 years he always carried a Ziplock of moth balls in the trunk and always added some when re-fueling. I think it had over 300M miles when he died, and his son still drives the car today.

I haven't needed to do this for my XJ, but I wouldn't hesitate. For years, I regularly added them when re-filling my previous car, with no known negative effects.

DISCLAIMER: I have not researched any environmental effects, BUT I never had clogging of the cat converter with my prior car - a '97 Mercury Sable wagon - or any other side effects, after years. (I guess I can't attribute the $3500 transmission failure at 56,000 miles... and, gee, then I got $3500 to trade it few months later - But this isn't the palce for that rant (if I cared about Ford.)