Check Engine Light Coming On?

Question

When I'm driving on the interestate, usually my check engine light comes on when I get close to 75 mph....sometimes it happens at lower speeds, but usually when I'm close to 75. The way for me to get the light to come off, is to simply pull over, turn off the car, and then start it back up and drive again. The weird part is that when the light comes on, my RPMs sky rocket, almost like I downshifted a gear (but its an automatic). I'm not sure if its transmission fluid or what, but I have no idea what to do. Any suggestions would be greatly appreciated!

and i notice people say Advance Auto Parts or Autozone, the problem with them is they say their machine will only detect the problem if the light is on, so when I go there, they don't have anything for me...thats why I was hoping it was something as simple as fluid or oil.

Answer 1

Take it to Auto Zone...they will check your car by computer and tell you what the problem is for free.

Answer 2

Any time the check engine light comes, it will leave a code regardless of whether it stays on or not. My code reader will read potential trouble areas even if the light does not stay lit.
Go down there and have them hook up the reader, if for no other reason than just to humor you and see what happens.
If you do decide to buy your own code reader, follow the directions carefully. You cannot run the engine with the reader hooked up or you will damage the reader or your ECU.
The torque converter control circuit may be intermittent letting the torque converter unlock, but if there is a great difference in RPM it could be the overdrive solenoid sticking. The cheapest fix for many transmission problems is to change the fluid and filter and have the bands adjusted.

Answer 3

Recheck the oil level on your dipstick again just to make sure your oil shows full. Then have the error codes read out from your computer at an AutoZone store near you. Otherwise you'll have to take it into a repair shop to have they diagnose the check engine light trouble codes. It's probably a coincidence. You could go back to the shop that changed the oil and see what they say. If any red dash lamp comes on, you need to pull into a repair shop immediately. You can drive the car to the repair shop with a yellow check engine light on.

Answer 4

I had a Chevy S-10 that did that. I drove that truck for 8 years with that annoying light coming on. Strangly enough the truck ran better every time the light cam on. Otherwise it coughed and choked. We had it to several mechanics and nobody could find a problem even using the computer key to check it. Also replaced the computer but no luck so we gave up and just drove it as is. It still runs and never changed or quit in 8 years. I would just leave it alone as long as it is running alright otherwise.

Answer 5

If you have a newer car the codes can be the point to the strangest cause. The maker of your car has diagnostic equipment that will find the problem.
Here's a for instance on weird codes.My father had a check engine light and the code pointed to a broken motor mount on a new Cadillac.

Answer 6

Do routine maintenance like changing oil and making sure fluids are replenished. Most shops can do a diagnostic to see if anything is obviously wrong. If not, the light is probably inaccurate.
I thought 70 was the speed limit in most places.

Answer 7

WRONGO! They do NOT need the LIGHT TO BE ON! Every car ha a MEMORY CIRCUIT that keeps track of ALL bad signals! ALWAYS include the CAR YEAR< make, model, ENGINE SIZE< mileage TRANS TYPE and COUNTRY OF ORIGIN with your CAR QUESTIONS! They are ALL similar but in many ways DIFFERENT! the ANSWER for most cars costs only about $25! Go to ANY OIL CHANGE cenerr and have them clean your THROTTLE BODY and IDLE AIR CONTROL VALVE to SHOWROOM CLEAN! the IAC valve fine tunes the amount of AIR entering the engine. BAD oil makes WAXY CRUSTY SLUDGE that BAKES into these items, and they STOP WORKING! The AIR/FUEL mixure goes awry, and then Thinghs can get CRAZY! ALSO power wash engine with GUNK ORANGE to remove ALL TRACES of ROAD SALT, and leaking fluids or GRUNGE that accumate on ENGINE METAL SURFACES! This aloows metals to BREATHE again and dissipate HEAT evenly! GOOD LUCK!! WHO MADE THSI CAR?? TRANS codes get stopred as WELL! BYE NOW!

Answer 8

You can get a cheap ODBII scanner at AutoZone or sears for as little as $50 on sale. So why not invest in one and have it scanned while driving on the highway?

Otherwise there's just too many possibilities. Besides you are not even telling us what year and make is your car. You'll save money in the long run by not spending money chasing ghosts.

Good Luck.

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Answer 9

I HAD THE SAME PROBLEM (if im right about what i think it is, haha) take it to a muffler shop and have them check out ur catilitic converter. if they say its screwed up, u found ur problem. it sounds a like a long shot, but thats the same problem i had. i tried adding transmission fluid, fuel injection cleaner, and a million other things and nothing helped it. everytime i got on the freeway my car would only go 45mph and take minutes for it to go up to speed without letting the transmition slip. if that starts happening to you, i would 95% sure its ur catilitic converter.

Answer 10

If AutoZone needs the light on to read the code...then don't shut the vehicle off. Ask a friend to join you, take it out on the highway, get the light to come on and have them read the code. Ask the question on here again when you know the code, and I'll bet you get a ton of responses.