Q: No power. Transmission shifts down and engine revs up but doesn't go anywhere

asked by on February 24, 2017

While driving up hill the truck will lunge forward sometimes. Then go right back to normal. Also the service engine light comes on and I pulled the code and it says knock sensor error. So I changed the knock sensor. But I'm still having the problem. When the SEL comes on the truck will shift down and the engine revs up but the truck doesn't pull. It just barely feels like it has any power. At this point I just don't know what to do
My car has an automatic transmission.

Hi there. In some cases, what you’re describing is caused by a restriction of fluid inside the hydraulic lines of the transmission, an inner seal that is damaged or the torque converter wearing out. This issue can sometimes be resolved by simply flushing the transmission fluid and changing the filter; while other internal transmission repairs are needed. The best advice I can offer is to start by flushing your transmission fluid and change the filter. If this resolves your issue; great. If not, feel free to have one of our mobile mechanics come to your location and complete a car is hard to shift inspection.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

My car won't shift out of first gear

If the torque converter is defective that could cause shifting problems, and other symptoms as well. There are stall speed and hydraulic pressure tests than can assist in diagnosing the condition of the converter. Other possibilities include the external controls...

Do I need a special tool to remove the knock sensor?

Hello. There does not appear to be any special tool required to remove the knock sensor on an 84 Corvette. Only the correct size socket should be needed in order to loosen and remove the sensor. The sensor is located...

Is it possible to fit a LT4 Supercharged 376ci / 6.2L Engine into a 1997 Z28 Camaro?

When changing the engine over from a Z28 to a LT4 Supercharged 376 CI engine, you may have to adjust the engine mounts to accept the engine transferring over. The blocks are about the same size and will both bolt...

Related articles

The Best Used Cars to Buy If You’re Over Six Feet Tall
While While shorter than average drivers can have a tough time finding the right car, it’s equally hard for taller drivers, perhaps more so. If you’re feeling squished, or have to hunch over the wheel to drive, then you’re not...
Understanding the GMC Oil Life System and Service Indicator Lights
Car symbols, or dashboard lights, are a car service reminder. The GMC Oil Life System indicates when and what service your car needs.
A Buyer’s Guide to the 2012 GMC Terrain
When When you look at smaller SUVs like the Honda CR-V and the Toyota RAV4, do you wish for just a little bit more space? But then when you look at the larger SUVs like the Ford Explorer or the...