Q: rough idle and low rpms at a stop light, but drives fine
I have a 2006 jeep grand Cherokee. Drives great but sometimes at a red light the rpms drop to about 750 then lower and shutters then jumps back up. It only does this when im at a red light.
My car has 86000 miles.
My car has an automatic transmission.
Recommended Services
| Car idle is rough Inspection | $94.99 - $114.99 | Get a Quote |
Hello. This is very common on this particular vehicle. Typically it is caused by a dirty or failing throttle body. I have also had a few of these with a sticking thermostat which causes the engine to run cooler than it should and makes the car run like this.
I typically start by cleaning the throttle body first. If that does not take care of it I would use a scan tool to check the coolant temperature and the throttle sensors. If you are thinking of having this done, have a certified mechanic inspect your rough idle and low rpm’s to make an accurate fix.
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 has a rough idle.
Hello, It sounds like maybe your idler pulley (https://www.yourmechanic.com/services/idler-pulley-replacement) or some other pulley on the motor has a bearing that is going bad. A technician from YourMechanic can trace down exactly where the noise is coming from by inspection. (https://www.yourmechanic.com/services/75-point-safety-inspection)...
Parking pinion in transmission broke
With the parking brake not engaging, caution should be observed. This vehicle has the parking pinion inside of the transmission and the transmission will need to be partially disassembled to fix this. A qualified technician will be able to diagnose...
Engine cranks but wont start.
From what you've described, it sounds like your timing belt teeth are broken off at the crank gear. You may have bent the valves now since the engine was turning and the cam was not. If this occurs it can...
Knocking noise - 2005 Scion xA
Hello. Assemblies such as power steering pumps can often be rebuilt or repaired, but the economics of it are usually only attractive to car enthusiasts or hobbyists. That is, IF there is something wrong with the pump, it is much...
Engine trouble
Hi Jo: Unfortunately, we need more specific information about your vehicle in order to recommend a service or to guess as to what's going on with your vehicle. If the engine is low on oil (https://www.yourmechanic.com/services/oil-level-is-low-inspection) it tends to make...
Car runs with the mass airflow sensor unplugged. If you plug it in it will die if the car is running.
This is a sure sign of a shorted mass airflow sensor. The reason it starts with it off is the computer sees no mass air signal and replaces it with an internal memory fake signal to use. This will let...
Peugeot 206 cutting out whilst driving 'Not idling??' 2004 Peugeot 206
Hi there - this problem could be in the wiring, with a possible electrical short (https://www.yourmechanic.com/question/electrical-short-in-car) that takes out power to the ignition. Depending on where the stereo installer took power for the new system, there may be a connection...
Water hose leaking at firewall of 2012 ford focus
Typically, those are molded 5/8 inch ID rubber coolant hoses that are retained by either spring steel clamps or adjustable stainless steel worm drive clamps. Once you remove the hose, even to inspect it, it will not seal well when...
It has been a warmer February day, but high only hit 68, so what could cause a water leak under the car?
Hi there. The leak seems to be coming from the windshield washer reservoir. Look under the vehicle with a flashlight and on the washer reservoir tank (https://www.yourmechanic.com/services/windshield-wiper-washer-system-inspection) and see if there is water droplets coming off of it. If so,...
Related articles
The Best Used Cars to Buy If You Live in a Cold Climate
If If you live in a cold climate, likely one of your biggest concerns when you are considering which used vehicle you should buy is how well it will perform in snowy, icy conditions. We have evaluated a number of...
The Top 5 Selling Cars in Alaska in 2012
Alaska Alaska requires a different kind of vehicle to handle both the terrain and the wintery conditions. While some of the most popular options for the Alaskan terrain in previous years included options such as the Subaru Forester and the...
The Most and Least Expensive Cars to Insure
Car insurance quotes depend on the car make and model. The Honda Odyssey is the least expensive and the Dodge Viper is the most expensive to insure.
Browse other content
Services
Maintenance
Estimates