Question'02 Astro shows only P0300, but engine does not misfire- ever. Wires very recent, plugs new, distributor recently replaced, gear new, cam timing chain tight, really strong engine. Code thrown under light to moderate acceleration, around 1,800 RPM, and with engine cover off you can hear a sort of rattle, churning, clatter, hard to describe sound. Not pinging, for sure. This is a very different sound, and the dash light will come on and flash when it happens.
I know the computer a$$umes misfiring when it calculates sudden changes in crankshaft rotation, and I've heard of timing chain and balance shaft problems causing this, but I'm hoping and trying to diagnose it without any more $ trial and error.
Could a torque converter problem, like a bad stator clutch, cause this? Any other thoughts or ideas?
AnswerOkay, here we go Rob.First, when the MIL (dash light) flashes like that it is telling you there is a misfire condition that can damage the cat. convertor.Now before you go spending money and or looking at the tranny, check these out instead:
-Check the ignition control circuit for a short to ground
-Ensure proper routing of the ignition wires
-make sure the coil wire is on all the way
-check for poor fuel
-is the fuel filter in need of replacing?
-check your injectors...high resistance in an injector can cause it not to work properly and it won't throw an injector code
-could the noise your hearing be a hanging valve?
I hope these checks help you find the problem, if not please let me know.....I'll dig deeper for ya.
