1996 Toyota Corolla Has A Low Idle

I have a 1996 Toyota Corolla 1600 cc which started to rev very low on start up to the point that it would cut out. A code reader showed a coolant temperature sensor code so i replaced it . Now when I start the car is does rev higher but not as high as i think it should and remembering it doing. After a period of time (few minutes) it will start to rev up to where it should be and then stay there longer than i think it should.

Repeated tapping of the gas pedal to take it off of fast idle will not cause it to drop down so something is amiss. I did not clear the code for the sensor problem could this be causing the computer to still read as though the sensor was not replaced or is it something else. I also need to replace an oxygen sensor ( after catalytic converter one) but I don’t think this would influence the engine revving problem.

Mechanic JK:
No, the oxygen sensor would not cause the idle problem you are having with your Toyota. The computer should have all the codes erased after repairs are made, but if the one for the coolant temperature sensor is still in it, no that won’t cause any problems. The car is now reading the correct temperature, that is if the sensor fixed it. You could still have a wiring problem to the sensor. Just because the code is for that particular part, does not mean the sensor is bad for sure. Clear the codes and see it if returns. If it does, more diagnosis is needed.

Since hitting the gas pedal seems to help, I would clean the throttle of any carbon. This will effect idle. Being that the car is 16 years old, there is probably a large buildup of carbon on and in the throttle body bore and plate. Check for free movement of the throttle cable between the accelerator pedal and the engine. It is possible you just have a binding cable. Also check for any vacuum leaks on the engine. This is another common cause of unstable, low or high idle.

There is also a part called the Idle Control motor. This does exactly what it says- controls the engine idle. If this is sticking, again caused by contamination, or the motor has failed, this could also be part of if not all of your problems. These usually will not set a check engine light on an older car. Newer cars it may.

Toyota Corolla Burning Oil

My Toyota Corolla 2008 1.8 petrol is consuming too much of engine oil. almost 1ltr after every 1500 km. Now days in morning its giving white smoke, after few mins it gets stop smoking. but oil consumption is getting increased day by day. There is no issue in power of engine or driving. I can feel while driving that engine is very much fine. can you please suggest what to do.

ANSWER: If you are getting smoke from the exhaust in the morning, and the engine is burning oil, this is a sign a worn and leaking valve seals. When the engine is hot, then shut off, oil will drip into the cylinder and be burned when you start it again. To check this, remove the spark pugs and look for signs of burning oil.

Toyota Corolla Humming Noise

My 2004 Toyota Corolla LE 1.8 L. It has 36,000 miles on it. I’m having a loud humming noise coming from the car, no matter how fast your going. The noise does stop if steer slight right. I’ve seen on the forums they say it’s the wheel bearing. I just want to confirm before I tear it apart. I’ve lifted the car up, there’s no play in the wheel. I’m somewhat stumped.

ANSWER: Yes, sounds like a wheel bearing. If the noise stop with a slight steer to the right, then the right front wheel bearing is bad because when going right, the body weight shifts to the left and takes some weight off the right front- so the noise stops or lessens.