Q: Car idles at high RPMs

asked by on July 22, 2016

My car has manual transmission. It has gone around 140,000 miles. I've been having some issues with high idling for more than eight months. When I drive it for a short while, it would start revving at high RPMs, over 2800 while it idles. It helps somewhat if I restart it quickly. This is happening with increasing frequency and at even higher RPMs. The dashboard doesn't show any lights on. What could be causing this?

Idling too fast can be caused by several things. But bottom line is that too much air is getting into the intake manifold. Manifold vacuum leaks are a common cause. Do a visual inspection to check for any vacuum hoses that are broken or fallen off.

There can be several possible causes for this. The intake manifold gaskets may be leaking. The power brake booster can be leaking - pinch off the big vacuum hose to eliminate that. A dirty throttle body can be preventing the throttle plate from returning to its closed position. The Idle Air Controller (IAC) can be sticky or failed. The Engine Coolant Temperature sensor circuit can be faulty making the Powertrain control module (PCM) think that it is freezing cold outside which requires a fast idle. Have the high idling issue diagnosed by enlisting a certified mechanic to visually inspect, test, and scan your car.

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

Car smells like very strong gas leaking at the bottom

Hey there, thank you for asking a question about your 2005 Saturn Ion. A "strong" odor of fuel is an emergency circumstance. If you park a vehicle with a known gas leak in a tightly closed space, such as a...

Car is not idling smoothly

Hello. This is typically caused by either a dirty throttle body or a bad throttle position sensor. I typically start by cleaning out the throttle body. That will usually take care of the problem. If it persists, I will use...

Antifreeze started leaking out of my car after I parked close to a curb. Some piece came off.

Hi there, thanks for writing in. I'd be happy to help. This suggests that the bottom of the radiator or radiator hose may be damaged, since there is antifreeze leaking. A physical inspection would be needed to confirm this. If...

How Long Does Clutch Fluid Last?

Clutch fluid in most vehicles is the same as what is used in most brake systems, brake fluid. The fluid over time will get contaminated with moisture, dirt, debris, and internal clutch master and slave cylinders wear materials. All of...

Automatic transmission issues 2001 BMW X5

Hello - I would first check the wiring connector at the transmission for good contact and secure connection, and fuses for the transmission controller. It is possible that an internal speed sensor in the transmission has failed. I would recommend...

my van is making clunk and vibration noises that worsen while coasting or with less rpms

Hi there. It sounds like the transmission is having an internal failure. Some other possibilities are wheel bearing, axle, brake caliper, and brake hose collapsing. A worn wheel bearing will have noise at all speeds while increasing noise and vibration...

my car idles high and will not shift out of first gear

Hello - there are several problems which could cause the behavior you mention. A failed throttle position sensor can cause the high idle, and poor shift/no shift behavior you describe since the engine & transmission communicate with each other over...

Overheating - 2004 Jeep Grand Cherokee

Hey there. When the car is stone cold (for your safety), check the level of coolant in the radiator and plastic reservoir, too. If the coolant level is full, a typical cause of this kind of overheating is a bad...

Why does fuse 13 under the hood keep blowing out?

The job of a fuse is to prevent electrical shorts or over voltage situations from damaging wiring or electronic components in the vehicle. If a fuse keeps blowing, there is an electrical short in that circuit that is applying too...

Related articles

What Is Direct Drive Gear?
Direct Direct drive is a type of transmission that allows for better gear shifting within a motor vehicle. Because fewer gears are connecting, the vehicle cruises better at a higher gear. That’s a fairly simple explanation, so let’s talk a...
Symptoms of a Bad or Failing Kickdown Cable
If you feel that your car's transmission is shifting roughly, too fast, or too slow, you may need to replace the kickdown cable.
Is It Safe to Drive With the Transmission Temperature Light On?
Most people don’t know very much about vehicle transmissions, and realistically, why should they? All you want to do is get in...