I have an irritating problem with my 1992 Camry. About 2 months ago the transmission began to slip (especially when cold) and the idle started to run about 1100 rpm. In addition, at about 55-60 mph there is a rythmic rumble/vibration from under the hood. So, my question is this - could these all be symptoms of a bad oxygen sensor or EGR, could it be a slipped timing belt, bad transmission or a combination of all 4. It could get very expensive troubleshooting this. Any help is greatly appreciated.

 

The 02, EGR and timing belt would not result in trans slipping. Is the trans slipping in all forward gears and reverse? Does the trans have the correct amount of fluid? Has the engine idle RPM increased under both the following conditions: when the trans is in gear and when in Park/Neutral?

Might be an issue with the torque converter clutch. Try the following to stall speed:

Warm up engine and trans and park in a safe location where there are no objects in front or back of the car. Engage emergency brake and press on brake pedal. With engine running shift into Drive. Then fully depress the throttle pedal with the right foot and quickly read the RPM. Do this again in reverse. Complete each test in under 5 seconds or the trans can be damaged.

In both cases the RPM should be 2450 +/- 150 rpm. If the RPM is 600 or more below these specs this issue could be a diffective torque converter clutch.

A diffective torque converter can cause vibration.

If the car has A/C, does turning on the A/C result in the idle RPM going even higher then 1100?

Check the front engine mount. Have someone rev the engine in gear (emergency brake and and brake pedal engaged) as you look at the engine. Keep to one side in case the car breaks free. Look at the engine to see how much it rocks as is reved.

 

I will try the troubleshooting tips listed below this weekend. I appreciate your input as this is driving me crazy. I did notice that if I engage the A/C - nothing happens - the compressor doesn't even kick in. If this was the torque converter, would it smooth out after it's warm? Another add-on symptom is uphill travel makes the trans jump in and out of gear. Anyway, I will post a reply this weekend after experimenting.

 

When you press the A/C button does the green light come on or blink?

 

It comes on and stays solid.

 

The A/C may be a separate issue from the slipping trans. Try hot wiring the compressor clutch to determine if it engages, if it does could be a problem with the Freon level or another component. If the compressor works, don’t operate it for more then a few seconds.

 

OK, I completed the Drive/Reverse cycle and the results were:
Drive rpm - 2400
Reverse rpm - 2000
I noticed that the engine/car shakes back and forth during this testing? If it were a torque converter problem, would warmer weather affect it? The reason I ask is that on the coldest mornings (less than 40 degrees) it is worse.

Thanks again

 

Forward stall speed is fine, reverse is low but not too low.

Check trans fluid condition and level. Should be pink in color and between the "hot" marks when trans fluid hot. Shift the trans from Park to Reverse and back again, then check fluid with engine running. Low or bad fluid can cause all kinds of issues.

Shaking would be normal. Other owners have implied a slight slipping issue when the problem was the front engine mount.

The fluid is basically a 10 weight high detergent oil and of course would be thicker at colder temps. This could make the torque converter clutch, clutch packs, valving, etc, respond differantly.

 

The vehicle does have 158,000 miles on it and I can't tell you if the tranny fluid or filterhas ever been changed. I plan to change the fluid/filter this weekend. Probably change the plugs and wires while I'm at it. Hope it is the "magic bullet". I will update afterwards.

Thank you for your help toyomoho!

 

If you do change the fluid, keep in mind about 2/3rds reminds in the torque converter. Thus you will need to do 3-4 drain and refills (over a period of a few miles to circulate the fluid) before it become clear and red.

The alternative is to do a flush type change. Remove the return line from the oil cooler that goes to the pan. Drain and overfill the pan. Run engine until the fluid stops coming out of the return hose, then repeat the fill, run process untill the fluid is clear and red. Have someone help so you don't have the trans operating without fluid and can signal to stop the engine.

The trans holds about 6 qrts, so figure this in when buying fluid and getting the right size if container.

Drain and clean the pan and filter change first, make sure you clean and replace the magnets in the pan. Then start the process.

This flush method is a little more work but the result is a cleaner fluid in shorter period of time.