Sticking valves

[Dave Mann]

I've experienced sticking valves twice, number 8, the first time after I ran out of Duckhams Q20/50, a detergent oil, and used Castrol classic 20/50, a non detergent oil, within 50 miles of the oil change. So I removed and cleaned the valve and guide and changed the oil to Unipart 20/50, another detergent oil, with no more bother till Unipart 20/50 was no longer available and number 8 stuck again when I used a non detergent oil. I changed the oil to Halfords classic 20/50, a detergent oil, didn't touch the valve and within a mile the valve freed up.