QuestionQUESTION: My cooling fan does not come on. It will turn on immediately when I turn on the AC, but doesn't turn on when the engine is running without the AC. I've change the thermal sensor so far, what should I do next?
In addition to that I failed emissions this morning, high HC and CO. I found afterwards that the O2 sensor on the exhaust manifold was completely unplugged. Is this likely the only reason why or should I look for other issues. This car only has 47k original miles and runs perfect. It passed with flying colors last time with no repairs since then.
ANSWER: Hello, I need to know which model and year Toyota you have. First reconnect the sensor, disconnect the battery for a few seconds, this should clear the code, then drive it and see if the light turns back on.
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QUESTION: Apologies, I thought I had given that info. 1991 Toyota Tercel with automatic.
ANSWER: No problem, by "thermal sensor" do you mean the sensor at the bottom of the radiator? When you disconnect the connector and turn the key on does it run all the time?
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QUESTION: I've resolved the cooling fan issue. Due to the fact that this has sat for so many years without being driven the contacts inside the motor weren't making good contact. I disassembled the fan motor, cleaned everything, and touched things up with a bit of sandpaper, and it works perfectly now.
What do you think about my emissions question?
"In addition to that I failed emissions this morning, high HC and CO. I found afterwards that the O2 sensor on the exhaust manifold was completely unplugged. Is this likely the only reason why or should I look for other issues. This car only has 47k original miles and runs perfect. It passed with flying colors last time with no repairs since then."
I get one free retest but wondered if there was anything else that I should look at before heading back to the testing station now that I plugged in the sensor? Thanks for your help.
AnswerReconnect the sensor, clear the code and drive it to see if a check engine light turns on, if it runs and idles smooth and the light stays off chances are good that it will pass, you may also consider getting a can of fuel additive that can bring the emissions down, these are available at most auto parts stores.
