Q: car jerks/gas pedal

asked by on October 10, 2016

I have a 2004 Altima 2.5S (Automatic). The car slightly jerks when shifting gears (much more noticeable in downhills) and that's frustrating in traffic because the car wants to change gear from 1 to 2 but I press the brake and that's a bad jerk. I have taken the car to 3 transmission shops and they all did a road test and said there's nothing wrong with the transmission. Also No fault code exists. At idle (P) when I give some gas to 3000 rpm, the rpm needle sticks at around 1500 on return for 1-2 second, then comes back down to 900. Looks like the gas stuck somewhere in engine. I had already cleaned the throttle body but no relief! Have this issue for 8-9 mounts and that's not getting worse nor getting better. Only one or 2 times when I turned the A/C on, the problem went away and the gas pedal became enough stiff and satisfactory. I think this problem appeared after I changed my dead alternator myself.

My car has 138 miles.
My car has an automatic transmission.

Hi, thanks for writing in. This is more than likely a fuel delivery issue, given the symptoms you describe. The idle air control valve is a unit that regulates the air flow into the engine as it is mixed with fuel prior to being injected into the motor. When this is not working properly, this will cause an imbalanced load of air and fuel to be supplied to the motor resulting in a loss of power or stall as you have experienced. This may also cause the car to have an irregular idle as you have described. I would recommend having an expert from YourMechanic come to your home or office to confirm a diagnosis on the issue and make or suggest the necessary repairs or replacements.

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 vehicle will crank, but won't start.I have changed the crank sensor, the cam sensors, the fuel pump, and the spark plugs.

You need to do a systematic diagnosis. Trying to fix a car by replacing parts until it works again can be a lot of work and very expensive. Look under the hood for any air hoses or vacuum lines that...

Dome light unit fell down

The sun visor has no serviceable parts and would need to be replaced if it is unable to stay in its stowed position. If the mounting hardware on the dome light is damaged then the dome light assembly will need...

My car rough idles and stalls, but no check engine light.

This issue is normally caused by low fuel pressure or a faulty injector, but since you have just replaced the fuel pump, this may also be a sign of a failing idle air control (IAC) valve. This is a unit...

Related articles

The Best Used Cars to Buy If You Live in a Hilly Area
Do Do you live in terrain that is hilly? Do your city streets feature plenty of inclines and declines that can be nothing short of treacherous in miserable weather? If so, when it’s time to purchase a car you’re looking...
The Best Used Cars to Buy If You’re a Massage Therapist
If If you're a massage therapist, one of the cornerstones of your business has to be that you don’t keep your clients waiting. That means you need a vehicle that’s reliable. You also will have to move your gear, including...
The Best Used Cars to Buy If You're a General Contractor
If If you're a general contractor, you probably aren’t in the market for a used car. More likely, you’re looking for a pickup truck, because you need to haul equipment and supplies to various job sites. Most contractors will likely...