My first visit - good to meet all you like-minded ladies and gents. Maybe and old question, but all advice is welcome.
My VR6 pinks like mad under acceleration once operating temperature is reached, running on Optimax. New cylinder head including valves, guides, springs, seals, cams 6000 miles ago. The pistons looked good when the head was off. Coil pack ignition. Exhaust gas analysis shows no problems at idle, so I assume the lambda is ok and not weakening the mixture outside the specified range. Water temperature about 105 in slow traffic, much lower at normal driving speeds, fans both operational, new thermo switch, new supplementary water pump, oil temperature often over 110.
How many knock-sensors are there, and where are they? Are they prone to failure/malfunction? Oil temp seems high to me, certainly a lot hotter than ever had with 16V 2.0 litre engine code ABF, so is there still an overheating problem? I suspect that the previous owner had re-chipped the EMU, but surely the knock sensors would do the necessary to the timing to prevent pinking.
all the best
Roger