tnag9494

I have owned numerous Camrys and ES300's over the years, so I am very familiar with a lot of things with regards to the V6 engine in both. I am not a mechanic but I get most of my information from forums like these so any information is much appreciated. I have been a member for a few years now, but for some reason I couldn't log into my old account so I got a new one. So here it goes.


I have a 2001 ES300 with only a P0300 code. It has me stumped because it could be a number of things I know. Without a particular cylinder, it is hard for me to pinpoint where the problem may be.


The car idles rough but once you start driving it doesn't seem to miss at all until you get around 70-80 mph. The rough idle is consistent throughout the drive no matter what you do. But it never jumps as it would with a complete misfire. Really stumped on this one.


I have not checked anything yet. I was hoping to get some info before spending so much time (which I don't have) on this.


Any help is much appreciated.

atlcal

I had a similar issue on my 99, random misfire, did not get a specific cylinder code on my ELM327 scanner. Plugged in the Techstream cable and booted up my notebook, and it immediately showed me which cylinder had a misfire. It was not failing enough to trigger the code for the specific cylinder. Moved the coil for the cylinder I saw misfiring to the adjacent, drove again, and the misfire moved with the coil. Put a spare coil I had in, and all is well again.

While the scanner and ELM327 units are nice, the Techstream does a far superior job of tracking exactly what is going on. For the $20 or so you can buy the cable for, it's well worth it.

tnag9494

The weird thing is the misfire and rough idling doesn't start until the car fully warms up. That doesn't logically sound like an ignition coil to me. Did you have that same problem?

atlcal

Ditto, it was more prevalent when warm than when cold. I could try and theorize why, but honestly, it didn't matter. Problem moved when I swapped coils, so it was clearly the problem. Dropped a new coil in, problem went away. It's not as though the coils are serviceable in pieces, it either works or doesn't, and I happened to have some spares set aside.