Well i've been having a ticking problem, and first it seemed like some valve train problem, but then we thought it was most likely exhaust manifold leak. we took it to our trusty german service guy (not GM, there is not GM place in germany!

) and when we started it up first thing he said was "spark plug's loose" then he said it looks like it could be exhaust gasket. so he said he'd order the part and we can drop by next week and get it changed over. so we go home and decide to pass this grandpa going really slow, of course we went WOT and then BAM the ticking is really loud and we have a big loss of power. ok the gasket went all the way... only we open the hood and there's a spark plug hanging... we dont know if the plug is still good, i'll check everything out and reinstall the plug tightly tomarrow and see if the ticking is gone.