Quote:
Originally Posted by JustDo1nMe
Hello, hoping I can get some help or see if anyone else has had a similar issue...
My 2018 ZL1 has just about 3000 miles. It was dyno tuned with a rotofab intake, ARH headers, borla cat-back, and LT5 throttle body.
Just before winter started, I was out on a normal cruise when the car started misfiring. It through a CEL (P0303) Misfire Cylinder #3. Along with the CEL, the instrument panel displayed errors (service rear end/axel). The codes go away when the car is shut off and then turned back on but will re-trigger once the car goes over 2k rpms. Even when codes are cleared... you can tell it has a misfire in the idle.
I have not tried any trouble shooting yet.
Any feedback is greatly appreciated. Thanks in advance!
|
A bad valve spring will cause an misfire. I know I have my SS over at the dealer NOW, and that was their diagnosis. The car also would give me a service stabilitrak error as well which would clear temporarily when you restarted the car. The MISS was most noticeable at idle. I was told by GM tech that GM had gotten a bad batch of valve springs and that they were going to replace them all just to be on the safe side. Had that spring BROKEN and the valve dropped, then that would have been BYE BYE motor. That's why it is so important that when you get a FLASHING engine light that you immediately get it looked at.