Skip the auto shop - Our mechanics make house calls

Q: idles rough-worse with a/c on

asked by on

car runs well but idles poorly coming back to idle after stopping, condition worse with a/c on.well maintained, all emission and electronic engine controls still original.have checked for vacumn leaks and all is well-i think!

My car has 100000 miles.
My car has an automatic transmission.

You will need to run a Check Engine Light scan. I suspect that you will have a problem with the EGR valve stuck partly open causing the internal vacuum leak and a rough idle. You can remove, clean, and reinstall the valve. If it still leaks then replace the valve.

If you need some help getting this fixed, feel free to contact a certified mechanic who can diagnose your rough idle and make any repairs that are necessary.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: Do any of your mechanics work on a 1972 Ford Bronco in zip code 75034 ?

Hi there. We have a few mobile mechanics in the Frisco area, so if you'd like to see if one of them could come to your location to complete an oil / filter change and top off fluids on your...

Q: The engine is off, radiator fan still works, AC issues

Since the wiring system has been modified and the fan wired hot at all times with the key on. I recommend having a mechanic diagnose the real problem with the wiring since it may be an issue with the internals...

Q: run away idle/engine speed

This can be cause by a few things. A sticking throttle cable or throttle body, due to excess carbon buildup, or expansion from heating, idle air control valve issue, it can also be caused by a faulty temperature sensor signal...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...