Is my transmission dying?

October 14, 2008 5:09 AM

Is my car transmission dying?

It is a 93 Camry with an automatic transmission. When the car is cold, if you try to accelerate the car shudders and seems like it's about to quit entirely and if you baby it, it will keep going. But after driving for awhile it seems to go fine.

posted by geos to travel & transportation (7 comments total)

It's probably something relatively inexpensive. I'm not entirely familiar with the Camry's fuel injection, but on all cars there's a circuit in charge of giving the engine a little extra fuel while it's warming up. That can get wonky and cause problems. It could also be as simple as spark plug wires or an ignition coil.

Take it to a mechanic. It won't be TOO expensive.
posted by paanta at 5:38 AM on October 14, 2008

It's your cold-start sensor.

I used to drive an Oldsmobile that wouldn't start back up if the engine was hot: we found out the sensor was stuck 'on'.
Your Camry sounds like it's got the opposite problem- the sensor is stuck 'off', so when you start the car it uses normal, hot-engine block injector settings, which don't work very well if your engine block's cold.
posted by dunkadunc at 5:59 AM on October 14, 2008

It could also be a plugged catalytic converter.

That tends to make things seem sluggish and delayed, too.
posted by Acari at 6:01 AM on October 14, 2008

It could be any number of things ranging from easy and cheap to difficult and expensive. On my car, this is a classic symptom of a bad VANOS system, which varies the valve timing, and that can be expensive to fix. (My car is not a Toyota.) Transmission-wise, an automatic, because it shifts via fluid pressure, will sometimes miss shifts and/or refuse to shift from gears while cold. But this doesn't sound like the transmission because of the sputtering you mention, the near stalling, and also the correcting itself as the car warms up. (Although, the transmission could correct itself as the fluid warms up.) It sounds more like something that controls the timing of the engine, the fuel delivery system, vacuum, or possibly a MAF. Probably not spark plugs or coil because it corrects itself as the car warms. Does it trip the Check Engine Light while it's sputtering, or any other warning lights?

Honestly, with so little information, you're just going to get a range of guesses. For a DIY approach, take it to Autozone and have the codes read for free and see if you get anything. Or hang about the Toyota dealer's service department and ask around. Otherwise, get it diagnosed at a mechanic.
posted by luckypozzo at 6:53 AM on October 14, 2008 [1 favorite]

So, if it's cold and you try to stomp on the gas pedal, it will try to die? The actual engine will stumble and shudder? But if you feather the pedal it will accelerate? And this goes away when it's hot?

If that's it, I'd guess that it's probably what paanta and dunkadunc said- some sensor is failing somewhere. Could also be something bad in the ignition system. I had a car with a bad coil that did this.

A failing transmission will usually not act that way. Signs of a failing transmission would be that it would take too long to engage in gear, and "slipping". That's where you can hear the engine rev up, but that the car doesn't move commensurately with said revving.

(A plugged catalytic convertor would act slightly differently- first, it wouldn't matter if the engine was hot or cold. Second, it wouldn't cause the engine to stumble. A plugged exhaust would cause the engine to only get up to a certain RPM. At that point, no matter how far you pressed the pedal down, the engine wouldn't go any faster. Like if you were on the highway and tried to pass, you'd hit the pedal, the trans would downshift and the engine just wouldn't turn any faster.)
posted by gjc at 7:00 AM on October 14, 2008

I think that what dunkadunc is calling a "cold-start sensor" is actually an Engine Coolant Temperature (ECT) sensor.
posted by rfs at 8:57 AM on October 14, 2008

it actually will take a long time to shift into it's highest gear when it is cold... I wouldn't say the engine stumbles, it's running but it feels like no power is going to the wheels.
posted by geos at 9:14 AM on October 14, 2008