When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So as promised, I started looking at the fix for this issue as car's off the road now and yeah, didn't take long to find the "likely" (not yet proven) cause of the problem :
Both sides knackered! But i'm giving it a full service, so will keep digging and see if I find anything else awry.
So Max Vehicles, maybe you want to look at your PCV lines (which I'm pretty sure these are, but happy to be corrected if wrong)