What is making my car do this?

Question

I have 44,000 miles and have had absolutely no problems. Lately, every once in a while, while sitting idling, the tachometer will slight surge up and then down, sort of like a missed heartbeat feels. Any ideas?

Answer 1

time to ad some fuel injection cleaner

could be the air cycling

Answer 2

Is the AC on? Many times the AC have a pressure switch and the Compressor will actually cycle off/on. The fan always run. If, the compressor cycle when you are idling the Engine may "Rev" (Speed up/Slow down), as the compressor comes on. It normal. To see what I say, turn the AC off. Start the car and with the car idling (However when it do this, I assume in gear with brake on) turn the AC on and see if it do what I saying. If, not, then it may be something else, but, I not think it to worry about.
Be sure you use Fuel Injector Cleaner, it just a Bottle of stuff you add to the fuel tank. I buy it for $1-2 and just use it once a month or every 2 months whatever you feel.
It may be about time for a Tune-Up also.

Answer 3

My first instinct is to ask if there are any accesories running on the vehicle I.E. air conditoining. If not it sounds like maybe the throttle body may have some carbon build-up. You can go to your local auto parts store and pick up a can of throttle body cleaner, disconnect the air tube at the throttle body, this tube should run from your air filter housing. Spray down the throttle plate, twist the butterfly so the thorttle plate opens and spray into the intake. Hope this is helpful.

Answer 4

You have time to gradually see how this problem develops unless it gets a lot worse real quick. In the mean time, you can do a lot of things yourself and the problem may go away on its own. First go to the http://www.mycarstats.com website and register your car (for free) to read other owner's complaints about your model car. Also read the manufacturer's technical service bulletins and recall information. Stop in to your local auto parts store and buy some Chevron "Techron" concentrated fuel additive. It's expensive, but worth the money in my opinion. It will help clean your intake manifold and fuel injectors. If you get a yellow "check engine" on your dash at any time, don't worry about having to stop the car immediately like you should for any red lamp indication on your dash. Actually, the yellow check engine light will be helpful because you can then have the computer error code read out to help diagnose the problem.

Answer 5

if you got the ac on,then it will do that,also a computer will do that,but nothing to worry about,mine does that too.

Answer 6

I wouldn't worry about it. as long as it doiesn't stay idling high, sometimes when you take your car to a place to get something fixed they make it worse

Answer 7

go to car mechanic