Q: Engine revs without touching gas pedal.

asked by on January 14, 2016

Whenever one of the controls are used such as the defrost, heat, or AC, the engine constantly revs up. For example, if I am not touching the gas or brake while driving and I use one of the controls, the engine revs up to the point that the vehicle accelerates, just as if I had pressed the gas pedal.

Engine idle speed is high Inspection $79.99 - $89.99 Get a Quote

Now the engine computer will raise the engine idle speed automatically to compensate for the additional load of the AC compressor and the electrical load of the blower motor when the AC/Heater controls are operated. This increase should not exceed 250RPM over base idle. If the engine idle does it may indicate a problem with the output voltage of the alternator. You may want to enlist the help of a mechanic, such as one from YourMechanic, to inspect and read out the fault memories in the engine computer to ensure no underlying problems exist.

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

What others are asking

Can I bypass my AC compressor pulley?

Hello. The type of engine you have will determine how this should be done. The easiest way to do this would be to install a bypass pulley in place of the compressor. There is a bypass pulley with a bracket...

Cold engine makes cracking noises on start

Hi, most likely, this noise comes from worn internal components in your engine that momentarily do not have oil pressure to eliminate metal-to-metal contact. When oil pressure comes up, usually within a few seconds of engine operation, pressurized oil prevents...

When i put my Car in drive or reverse i lose power but in park or netural the voltage is normal

Hello there, many faults will cause your battery light to be on when your 2005 Ford Crown Victoria is in drive or reverse. You have done well in replacing parts so far, but the vehicle must be diagnosed fully before...

Converting to hydro-boost braking system on a 1990 Thunderbird Super Coupe

It depends on what you want to do. If you want to keep the car, I would convert it to hydro-boost brakes. It's a better system. Forget about that ABS system. The old ABS systems didn't work all that well....

Blue smoke oil leak

Hello. The valve cover and the spark plug tube seals may be leaking oil causing the blue smoke you see coming from the tail pipe of your 2004 BMW 745Li. The valve cover gasket and spark plug tube seals are...

where is the bank 2 sensor 1 located on a 2010 ford f-150

When it comes to a Ford, cylinder #1 is on the passenger side of the vehicle, so that makes the passenger side Bank 1. Bank 2 is the driver's side of the engine. Sensor 1 is the sensor in front...

when i pump gas the pump is triggered to stop before its full

Hi Sparrow. Thanks for the follow-up question. When a gas pump shuts off sooner than it should, it's due to one of two possible issues. Either the pump is damaged, or there is an issue with the fuel tank -...

During acceleration past 30mph a lot whine starts like a her engine along with very light almost grinding feel in accelerator

Hello there. Many faults can cause a whine in your 1993 Ford F150 under acceleration. The most common faults would be a belt tensioner, idler pulley, alternator, power steering pump, wheel bearings, or a failing drive belt. A qualified Technician...

Engine rattled, something fell out, and engine died

Hello. I would go ahead and follow the dealership's recommendation and have the updated water pump installed. I would also recommend having the belts, and any other pulleys, replaced if possible. If the vehicle is still under factory warranty then...

Related articles

The Top 5 Selling Cars in Florida in 2012
Florida Florida offers great weather year round, and the fact that snow and ice never factor into the equation means drivers don’t have to focus on the overall vehicle handling as they do in other states. The best selling cars...
The Top 5 Selling Cars in Connecticut in 2012
Connecticut Connecticut offers plenty of rain and its fair share of snow during the winter months, which means drivers need vehicles that can handle these conditions. Top selling vehicles in previous years have included the Toyota Camry, Corolla and the...
Does Running My AC in the Summer Keep My Engine Cooler?
When When you engage your air conditioning in your car, it is usually summertime and hot outside. Air conditioning serves to remove heat from the inside of your vehicle by circulating a refrigerant through the evaporator core in your dashboard,...