03 ESV - 6.0l - 60k miles - reg serviced at dealer since new
passing a transport a couple weeks ago (@5000rpm) the engine sounded like a stick was in the fan shroud...loss of engine power...as soon as I let off - it stopped...then everything ran fine
couple days later, same thing happened - this time I saw the check engine light flashing...but as soon as I backed off, it went away...continue normal day to day driving - no probs (but does feel a little "sluggish")
last week it happened again but this time the check engine light stayed on...called up Onstar, and they diagnosed "a PCM problem - get to a dealer asap". Other than the light - everything ran fine. Took it to a shop around the corner from where I work and they hooked it up and pulled a bunch of misfire codes - mostly #1. Changed plugs, wires, fuel filter...no difference. Oil pressure - perfect.
end of the day he says "you have a spun bearing"...the noise is causing the knock sensor to retard the timing which is giving you the loss of power. I don't believe him cause the engine runs fine until high rpm and the timing goes off...thinking that the misfire(s) is causing the noise that the knock sensor is hearing. He says fine - go get a 2nd opinion - but he's positive the engine is toast
so I pay and go to leave - now the truck can barely drive down the road! Idles fine, but will barely accelerate (bogs)...so I bring it back, we put it on the scanner - now its showing misfires on 1-3-5-7 ...the whole one side of the engine. Their explanation - "its getting worse"
anyway, been away at work since and haven't had a chance to have it towed for the 2nd opinion and its killin me.... I mean I've owned a ton of 4.1 Caddys so I know a knock when I hear it...this isn't making much sense to me!
any thoughts/ experiences?