Q: Bad idle with no check engine light on

asked by on November 27, 2016

I was moving my sister's stuff after she passed away, and all of a sudden my van had a rough idle. I have changed the plugs, wires, fuel injectors, fuel filter and cap and rotor, and I still have a rough idle. I was told to use this stuff called Restore, you add it to your oil, I did but if I go too far with it it stalls out, but starts right back up with No problem. Do you think it could be the ignition coil? Please let me know Lorraine

My car has 177000 miles.
My car has an automatic transmission.

Car idle is rough Inspection $94.99 - $114.99 Get a Quote

Greetings, I’m sorry to hear about your sister. A rough idle may be caused by many different things such as low fuel pressure, low voltage to the fuel injectors, dirty fuel injectors, a vacuum leak, a faulty Oxygen sensor or a dirty or failing idle air control valve. Any of these possibilities relate to fuel delivery issues that will disrupt the normally balanced air/fuel mixture that would otherwise allow the motor to run smoothly. It sounds like in your case you have touched on all of the ignition related components. Try checking some of the above items that can impact the fuel delivery to see if this doesn’t solve your idling issue. I would recommend having an expert from YourMechanic cometo your location to diagnose your rough idle problem.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Head gaskets failed how likely is it to happen again?
Hello! Thank you for writing in with this question. The design of the “boxer” engine makes for a high probability of head gasket problems. Coolant and oil drainage isn’t like typical “V” or inline style engines, so coolant and oil...
Smoke coming from under the hood.
Engine coolant has a very distinct smell when it burns, a sweet candy like smell. If your coolant levels in the radiator aren't dropping, a leak can be ruled out. If the level is low, that means you are either leaking,...
2003 Chevy Maliby shakes when it's put in drive
Realize that, at that age, those things can get worn. First check for vacuum leaks. If you don't find any vacuum leaks, then try and have the fuel injection system cleaned (https://www.yourmechanic.com/article/how-to-use-a-fuel-injection-cleaning-kit-by-ed-ruelas). A lot of times, the cleaning would help....
Tail lights suddenly not working.
You have a broken brake light switch connector wire. The green wire with a red stripe goes to the brake lights and will cause the brake lights not to work. You may also have a problem with the turn signal...
Have 2011 Chevy Malibu car completely died while at stop sign with foot on brake would not start after that could that be the thro
Hi there. It is possible that the throttle body might be the source of this problem, but also the mass air flow sensor, fuel pump relay or one of multiple ignition system components. The best way to determine what is...
Would an ignition cylinder from a 99 4Runner fit a 91 4Runner?
Generally, a switch assembly from 1989 through 1994 will work on this vehicle, but to get a precise answer if you plug in your vehicle data on-line at Car-Part.com (http://www.car-part.com) you will get not only all possible interchange years but...
Loss of brake power/pressure once ABS is activated
If the pedal is sinking to the floor, you have a problem with trapped air in the hydraulic system, a leak, bulging hoses to the 4 wheel positions (the flexible rubber hoses) and/or a faulty master cylinder. To have the...
Oil pan
In your application, the engine under covers will need to be removed to gain access to the oil pan. You do not need to lift or move the engine. YourMechanic does offer oil pan replacement, on a mobile basis, for...

Related articles

5 Essential Things to Know About Idling
Everyone Everyone does it, whether waiting for the kids to get out of school or someone running into the store for an item or two. The problem is, idling, which occurs when you sit with your vehicle running but not...
How to Buy a Good Quality Idler Pulley
The The idler pulley system drives a car’s alternator and is part of a belt and pulley system that also covers power steering, the air compressor, and other devices. The pulley is essential; with all of the important equipment that...
How to Keep Your Car From Stalling
When When driving a car, we expect it to get us from point A to point B without any issues. It can become unnerving to drive if your car stalls randomly when coming to a stop, whether it is at...