Thanks for the description. What would cause the hot spots on the cylinder walls? Would that be from carbon build-up? And if so, is there anything you can do about it, like driving the engine hard for a while?

 

Try disconnecting your MAF sensor and drive like this for a few days. You will get a CEL, but don't worry about it. Your ECU will go into some sort of default mode, and you may no longer have pings. If thats the case, then most likely your MAF or O2 sensors are shot.

 

I used to have a pinging problem in my GS430, and I couldn't find what was causing it. I took it to a diagnostics shop, and they said my ECU got corrupted, and they reprogrammed it. Cost me $500, but the problem came back a month or two later. It turned out that K&N filter was the cause. The oil from the filter got onto the MAF, and MAF wasn't sending the correct info to the ECU. I replaced the filter with OEM, cleaned the MAF, and the problem is gone for good.

 

I had a ping/ticking noise on my GS430. DROVE ME NUTS. Of course the dealer "could not hear it". I had a fellow CL member come drive my car and we didn't get more than a quarter mile away and he says "YOU NEED TO GET THIS FIXED!".

Left it at the dealer for a month. Ended up being the fuel return lines vibrating against the firewall on the car. They insulated them and all was better - for a while.

Anyway, I know it is a long shot, but I just wanted to make sure you have them check into other things like this.

 

$500 for an 'ECU reprogramming'?? That's usually done by just disconnecting the battery for a few minutes. What exactly did they do for $500??

 

Okay I thought it was just me and I didn't say anything

 

Oh you're being so well behaved these days.

 

Yeah, they just simply ripped me off, but its too late now.

 

Wait.. I thought these cars were trouble free??? Och 500 bucks?? wow..