sparrowhaw

Last week I parked my 1998 Lexus ES300 in front of my house, and turned the key to the off position. The engine kept on running, albeit at a much lower speed than the normal idle speed, and started to make a horrible noise. I turned the key back to the on position, and the engine went back to normal idle speed and the noise went away. Turned the key back to off position, and the engine went back to the very low running speed, and the horrible noise came back. I did this a few times, pulling the key out of the switch as well, and the same thing kept happening. Since I didn't want to leave the car running in that state, I thought may be disconnecting the battery terminals might result in the engine being turned off. I went into the house to get the tools, and when I came back out after about 90 seconds, the engine had stopped running. But I noticed that the battery had gone completely flat (no lights, remote wouldn't work, etc.).

I called AAA the next day, and as soon as the guy connected his battery to my car, the engine would start and go right into normal idle speed (no low running state with horrible noise), without the key being in the ignition switch. This freaked out the AAA guy, who thought there might be a ghost inside the car! He connected his battery a few times, and every time the engine would start running at normal idle speed.

I think the problem may be with the switch being faulty, but I can't explain why the battery went flat in about 90 seconds. I also can't explain why the engine would go into the low running, horrible noise state at first when I was originally trying to turn the key off, but when the AAA guy connected his battery, without the key being in the switch, the engine would go into normal idle running speed, instead of going into the low running speed with the horrible noise.

Any thoughts would be appreciated.

Cheers!

CUMan

I had a similar experience a couple of years ago with our 94 ES.

The car first started having starting problems. My wife would have to turn the ignition key on and off numerous times to get the car to crank. It would not click, like when the battery is low. There was just no response. I found that the battery had one cell that was a bit low, and I replaced the battery. This made no difference. I then replaced the starter relay. No difference.

At times during this period, the car would not turn off properly when the switch was turned off. It would do what has been called "dieseling." The engine would run in a very strange way, shaking badly. This would eventually stop in a few seconds.

Eventually, I decided that the problem had to involve the starter, and I changed it out. This stopped the problem, and it never returned.

I am no mechanical expert, but I would hazard a guess that your starter was turning over the engine when your car did this. The ignition was off, and the car would not run properly. The power draw from the starter ran your battery down. I don't have a clue as to how power would get to the starter with the ignition switch off.

I would suspect you need a new starter; or possibly just a starter solenoid. I replaced the entire starter since our car had about 150,000 miles on it when this was occurring.

sparrowhaw

I took the car in, and they replaced the starter (about $500, inc. tax).
All is fine now.

Thanks for your input.