help! when cooling fan turns on, causes car to idle erraticaliy then stall!
#1
Driver School Candidate
Thread Starter
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
hello all.
i was sitting in rush hour traffic with the windows down yesterday and noticed the idle while waiting at a red light, started to go up and down and then the car stalled! I put the car in park and started the car fine, but when the idle dropped again it stalled again! i gave it some gas and the car didn't stall, so while i was at the light i put the car in neutral and played w/ the gas a little bit to keep it from dipping. when i started moving again and got out of traffic, the idle started behaving. I did numerous searches and couldn't find a complete answer. some people say its the TPS, some say its carbon buildup or a dirty throttle body. anybody experience this? now as an added bonus , there was an 18 wheeler behind me when my car stalled, and he thought i was moving so he hit the back of my car! trunk is dented in 3 places! i got to the side of the road to look at the damage, and the 18 wheeler sped off in the rest of rush hour traffic and he didn't have a rear license plate! someone please help me w/ the idling issue! oh yeah, i drove the car to work today and everything was fine until about 20 minutes. i pulled into the parking garage and let the car sit in park and i let it run. i noticed the erratic idle started happening when the fan for the car turned on. when the fan turned off, the idle went back to normal. i don't know if erratic is the word, but more like a rough idle, kinda like fluctuating between 0 and 1000, and wanting to kill the car when it goes to that 0-200 rpm range.
THANKS IN ADVANCE!
i was sitting in rush hour traffic with the windows down yesterday and noticed the idle while waiting at a red light, started to go up and down and then the car stalled! I put the car in park and started the car fine, but when the idle dropped again it stalled again! i gave it some gas and the car didn't stall, so while i was at the light i put the car in neutral and played w/ the gas a little bit to keep it from dipping. when i started moving again and got out of traffic, the idle started behaving. I did numerous searches and couldn't find a complete answer. some people say its the TPS, some say its carbon buildup or a dirty throttle body. anybody experience this? now as an added bonus , there was an 18 wheeler behind me when my car stalled, and he thought i was moving so he hit the back of my car! trunk is dented in 3 places! i got to the side of the road to look at the damage, and the 18 wheeler sped off in the rest of rush hour traffic and he didn't have a rear license plate! someone please help me w/ the idling issue! oh yeah, i drove the car to work today and everything was fine until about 20 minutes. i pulled into the parking garage and let the car sit in park and i let it run. i noticed the erratic idle started happening when the fan for the car turned on. when the fan turned off, the idle went back to normal. i don't know if erratic is the word, but more like a rough idle, kinda like fluctuating between 0 and 1000, and wanting to kill the car when it goes to that 0-200 rpm range.
THANKS IN ADVANCE!
#4
Lexus Champion
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Insure the battery connections are tight and clean. With the engine off and cool, turn the fan blades by hand to insure the fan motors are not physically bound up and hard to turn.
This could be an idle control engine problem or an electrical problem.
Locate in your area a reputable auto electric / alternator repair shop (yellow pages or internet) and schedule have the electrical system checked out. This will eliminate the alternator, voltage regulator and the battery itself. They can measure the electrical load on the alternator with the fans on as the cause or not.
This could be an idle control engine problem or an electrical problem.
Locate in your area a reputable auto electric / alternator repair shop (yellow pages or internet) and schedule have the electrical system checked out. This will eliminate the alternator, voltage regulator and the battery itself. They can measure the electrical load on the alternator with the fans on as the cause or not.
#5
Driver School Candidate
Thread Starter
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
well ok, i went to lunch and tried turning the a/c on and headlights on but the idle was still going up and down when i was at a stop and the car was in drive. its kind of scary seeing the idle dip down to the 200's and the car starts to shake like its about to stall. so the idle control valve or TPS sensor. will unplugging the battery resolve this issue? is there a fuse that i can pull that resets all the electronics and the ecu? where is it located? thanks!
#6
Lexus Fanatic
iTrader: (13)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
Originally Posted by GSTEX
well ok, i went to lunch and tried turning the a/c on and headlights on but the idle was still going up and down when i was at a stop and the car was in drive. its kind of scary seeing the idle dip down to the 200's and the car starts to shake like its about to stall. so the idle control valve or TPS sensor. will unplugging the battery resolve this issue? is there a fuse that i can pull that resets all the electronics and the ecu? where is it located? thanks!
But no, unplugging it I don't think will resolve the issue
Jonny
#7
Driver School Candidate
Thread Starter
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
hmm. my g/f is going to drive the car tommorrow and i don't want it stalling on her. thats why i wanted to pull the fuse and reset battery for a temp fix for 1 day.
Trending Topics
#11
Pole Position
iTrader: (7)
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I have some new findings today as well. As I was parked, I waited for the temperature to reach operating temp. Once the cooling fan kicked on the idle would drop and it would feel like it was misfiring. I opened the hood to inspect, I noticed that when the cooling fan came on with the hood open that the idle would stay normal. I then lowered my hood and waited for the coolant to cycle again to turn on the fan. Sure enough it idled rough when the fan came on. I suspect a sensor is failing when it receives direct hot air coming off the radiator. I will be testing some areas with a heat gun tomorrow while it is at operating temp. Anyone else has any idea?
#13
Thread
Thread Starter
Forum
Replies
Last Post