I'm having engine troubles at the mo and I've got the heads off ready to be checked but I'm also convinced I've got problems with the pistons too. Mr Haynes says check the clearance between piston and barrel (should be 0.03 - 0.06mm new from memory), wear limit is 0.2mm, I can easily get 0.2/0.3 feeler in there.
It has been burning oil (oily plugs) and blue smoke with start up, it has also been making a knocking sound (with a bit of spluttering) for the first few seconds until it stops (oil burnt off, etc). Initially, I put the sound down to the hydraulic cam followers being drained and taking a while to fill but I'm not convinced as the sound was more 'knocky' than 'tappety' (my English teacher would be ashamed).
I've done some digging, and there is a symtom called 'piston slap', when the bore or/and piston have worn (too much clearance) and will knock until rings/piston heat up and expand taking up some of the clearance and reducing the noise.
I suspect I'm gonna have to drop the pistons and barrels off and get them properly measured (I was hoping to leave the lump in the van)
.Am I barking up the wrong tree? Anyone else had any experience of this on the WBX engine?
Cheerz (again)
