QuestionI bought my 1999 xle Sienna at 48k miles. It had the oil gelling problem, but I had the full cleaning service and with regular oil changes have had no further issues. I had the 60000 mile service at 58k miles. I also had injector and transmission cleaning, new battery. Since then, I began having some problems with hot starts. It always requires a lot more cranking than any of my previous toyotas (7), which started with just a tap of the key. Intermittently, after the engine catches the rpms fall too low and the engine quits. This may happen a few times in a row. If I rev the engine myself I can prevent it from quitting. Then, sometimes it idles just fine.
At the end of a cross country trip this month, my fuel tank changed the way it registers full (the needle doesn't go up as far) and simultaneously my gas mileage started dropping off. I always keep precise records of gas and mileage. My average went from 24 (I do a lot of hiway miles) to about 17. I changed the air filter, which seemed dirty and gained back to about 20. I have tried using higher octane, no change.
My mechanic suggested it could be an O2 sensor but no codes have been pulled!
I have never has such problems with any of my toyotas! I am now at 68k miles- so young. Please help because my dog LOVES this van!
AnswerThe problem is probably with the isle speed control valve located on the throttle body, try having it replaced, I'm sure this will fix the stalling and erratic idle condition.
Any malfunction with the 02 sensor will make the check engine light come on, this is not your problem.
