Since the first day i bought my 156 2.5 (two years ago) i thought the tick over was lumpy for a V6, "They all do that Sir" said the 'specialist' i bought it from (Yeah, right). Had an expensive diagnostic done at the local Dealer, they didn't have a clue either.
Car has now done 110500 miles, doesn't appear plugs were changed at last cam belt change (NJS), at 78000 miles. They were changed at 63500 miles by Raponi Rockwell in London according to old bills.
Anyway i recently got Smaky to have a general look over the car, first thing he said was "tick overs a bit lumpy", at last thought i someone agrees with me, i'm not going mad after all.
So last week Smaky popped a new set of Denso plugs in, weird thing was two of the rear plugs appeared never to have been changed ever!, really badly oxidised up, the other four didn't look anywhere near as bad??. Odd or what?.
Quick throttle body spring clean as well incuding electrical bits.
Result. Smooth tick over. Far better throttle responce. Better, sharper acceleration. Improved fuel consumption. Nice one Smaky