02 trailblazer engine?!

[black87chevy]

my moms 02 trailblazer is having some problems. it is running really really rough, like its running on 5 cylinders. the check engine light stays on and when you start to accelerate the light starts flashing. it has no power untill maybe 2500rpm then it feels like its trying to smooth out but never really does. the motor is making almost a knocking sound but not loud at all, like you cant hear it till you open the hood. i cant figure out what it is. help please!?!?

[transplant]

I have seen some with valve seats recessed in the head. I would do a cylinder leak down test.

[bigbob6988]

http://www.trailvoy.com/

[85k5]

flashing SES light is a misfire

[black87chevy]

a misfire would make sense.

[85k5]

i would check the plugs the boots and all 6 coil packs for a start....sounds like you may have a weak or intermittant coil pack