Car suddenly revs with loss of power

I have a 2004 Toyota Corolla (with only 29,000 miles) that has

something wrong with it that Toyota dealers are unable to figure out. Ever since we got the car, there has been periodic loss of power. This last time was on the highway. I was going 65mph, when the engine suddenly revved up to 6000rpm with a total loss of power. When I took my foot off the gas, the revving stopped. When I put my foot back on the gas, again the engine revved upto a high RPM but there was no power. I pulled off the highway, got a tow truck to take the car to a

Toyota dealer. And the dealer said there was nothing wrong with it. I then drove the car another 600 miles and that problem hasn’t returned, but I’m just waiting for another episode. It seems dangerous to drive the thing on a long trip. We’ve had the car to three different Toyota dealers with this problem in the past. Once they said the transmission fluid was low. The other two dealers said they could find nothing wrong with the car. I’m at a loss as to what to do. If you have any suggestions for me, I’ll be so very grateful.

Miss speaking a problem often makes diagnosis difficult. In my effort to read between the lines I must guess that your transmission is slipping while in overdrive. Has the transmission been serviced regularly? Is the fluid bright and at the correct level? Is the cooler free flowing?

When you speak to a “service writer” who is in a hurry and complain of power loss your vehicle is assigned to a mechanic who looks for poor engine performance… Your problem doesn’t seem to have anything to do with engine performance.

This transmission sounds like it is having an internal problem, where it is loosing fluid pressure to keep the high gear clutch pack engaged. Why this is happening, I don’t know, but it is a transmission problem. Keep documentation on the problem and when it occurs. This will be important to get the problem corrected under warranty.