Ive just spent ages stripping my z32se engine on the hope of curing this slight ticking noise which i suspected to be a cracked exhaust manifold on cylinders 1,3 & 5.Those who know this engine will know how much work is involved .Especially after a hard day fixing everyone elses cars for the garage i work for . Anyway once i had the manifold/cat on the bench the soot which i could just make out when it was on the car didn't appear to look that serious. I inspected further and for the life of me couldn't find any cracks or other tell-tale signs the would indicate a manifold fault!!!!!!! So after banging my head against the wall for a few minutes i went forth and put it all back together on the hope of maybe, just maybe fixing the noise with no explaination lol!!! And to my suprise the noise was STILL there? lol!! Im now wondering if its maybe early signs of a hydraullic tappet starting to break up??? I know its my job to listen out for strange noises on cars and the ticking noise is so minimal. But its really doing my head in!!!any suggestions much appreciated.