Skip the auto shop - Our mechanics make house calls

Q: Is my transmission going in my car?

asked by on

Everytime i start my car it revs itself up to 4rpm and holds for a moment then drops down to 1- 1 1\2. As soon as i put my car in drive it will either "chug" and not allow me to accelerate or as soon as i press on the gas my car will go and basically drive itself(same in reverse only with othe the chugging). When i do drive my car bounces between 1 1/2 and 2 rpms. There are also points were my breaks are great or almost dont work. I have just replaced the o2 and speed sensors and the thermostat almong with unplugging the battery.

My car has 170000 miles.
My car has an automatic transmission.

A: You need to have the computer tested for co...

You need to have the computer tested for codes and the engine checked for a vacuum leak to the brake booster. This would account for the high idle and lack of brake power assist. The most likely cause is that the brake booster hose came out when you were working on the engine to replace the O2 sensor. A certified mechanic could help you diagnose your acceleration issue and the other symptoms you are describing to find the right fix.

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・Save up to 30%

Get a quote

What others are asking

Q: Car smells like gas, possibly a leak.

If you smell fuel in your vehicle you almost certainly have a leak. I would recommend not to drive the vehicle until the source of the smell has been found. Mobile technicians from YourMechanic are available to inspect your fuel...

Q: AC leaking

Hi. While there is a small amount of refrigerant that will be lost by the AC system over the years, there is also a chance a leak may have developed. The system's pressure needs to be checked and recharged to...

Q: Front driver side wheel wants to lock up while driving it'll pull to the left and tries to stop.

There are a few possible causes for your brakes to engage. Caliper pistons can be seized, hoses can be pinched or closed off on the inside, or even electrical problems with the ABS. Have your vehicle scanned for ABS troubleshooting...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...