: High RPM (3k and up) CEL



06BlackV
05-01-12, 08:00 PM
Hey guys, i was driving on te highway today i was doing 80mph in 5th gear (3k -3300 rpm) and i noticed my CHeck engine light flashing , it continued to flash untill i slowed the car down (2700 rpm and below) then the light quit flashing. Possible misfire ? And if so, typically where to i begin my diagnosis? I changed my plugs and wires about 5000 miles ago. Thanks for any advice

odthetruth
05-01-12, 08:04 PM
Read codes. See if any are still in system and report back.

06BlackV
05-01-12, 08:29 PM
Read codes. See if any are still in system and report back.

I get no codes when light is not flashing , i have a basic obd2 scanner , can i scan it while on highway and the light is flashing ? I really dont want to damage my cats in attemping this :/

darkman
05-01-12, 08:59 PM
I get no codes when light is not flashing , i have a basic obd2 scanner , can i scan it while on highway and the light is flashing ? I really dont want to damage my cats in attemping this :/

It is possible I suppose that your OBDII scanner would flash the code that is "trying" to set - it is worth a try. Attempting this should not damage your cats. In theory a code will set and the check engine light will stay on if the condition threatening the cats hits a certain threshold.

If this does not work, I think a shop with a TechII Scanner check the error history and find out what the intermittent condition is. Otherwise, you can wait for a code to set.

The list of problems that could cause this is fairly long, including loose wires or connectors, vaccuum leaks, a bad O2 sensor, contaminated fuel, or fuel filter, etc. In fact, an out of balance tire can, in theory, cause a general misfire code P0300 to set.

Cadillac Cust Svc
05-02-12, 01:05 PM
Sorry to see you experienced this, 06BlackV! Have you received the message again since then? Malfunctions often will be indicated by your OB II system before any problem is apparent. I'm sure you've already researched it in your owners manual, but I just wanted to confirm that your CEL light flashing does indicate a misfire condition was detected. Page 3-42 of your manual gives helpful tips to prevent more serious damage to your vehicle.

Please keep us updated!

Best,

Katie
Cadillac Customer Service