Skip the auto shop - Our mechanics make house calls

Q: Car idles at high RPMs

asked by on

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?

A: Idling too fast can be caused by several th...

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.

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

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 shudders and idles low - 1992 Toyota Cressida

It is possible that this is a misfire condition either due to a faulty ignition system component or fuel injector that is creating a power imbalance that will cause a shudder sensation. The fuel system and ignition system should be...

Q: I have a 02 chevy trailblazer I went to step on the gas pedal and all it did was revved up but no go I pulled over and it died I t

This may be caused by many things such as low fuel pressure, a bad mass air flow sensor or a faulty idle air control valve. Low fuel pressure can cause an engine to starve for fuel due to irregular fuel...

Q: The radio will not power on. 2001 VW Passat

Hi there - first task is to check the fuse which powers the radio. If the fuse is good, check the operation of other devices powered by the same fuse for operation. If the rest work, then the problem is...

Related articles

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...
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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...