Skip the auto shop - Our mechanics make house calls

Q: fluctuating rpms and speed odometer

asked by on

I have a silverado hd 2500 with Hugh highway miles but the problem I'm having is when accelerating it seems to bogg down and rpms go way up and speed odometer bounces up and down then when I let off accelerater it goes to the speed I'm going I tried getting the computer read but the parts stores said it won't read what can cause this

My car has 200000 miles.
My car has an automatic transmission.

A: It sounds like the transmission is slipping...

It sounds like the transmission is slipping and causing the RPM to go high and the speedometer to jump when the transmission is slipping. Have the computer tested for communication problems and the transmission for slippage. A technician from YourMechanic can help you pinpoint the issue so that you can diagnose both your acceleration and speedometer problem.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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

Q: Car shuts off when stopped or going slow

There are many reasons why a vehicle may stall at a stop or at low RPM. I would recommend having your vehicle's stalling issue inspected at by a knowledgable technician, such as one from YourMechanic, to determine the exact nature...

Q: Car idles Rough when stopped

Did you change the right fuel injector? Bank 2 is on the passenger side of the engine. If you have tried ignition and you have tested fuel pressure and made sure the fuel injector is ok. next check engine compression....

Q: Speedo dial is 10mph lower than actual speed

This could be caused by a design flaw in the calibration reset of the cluster when you turn on the key. You can try to disconnect the battery for a couple minutes then reconnect it. The speedometer will reset itself...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...