Yes, there were some complains of valve train noise, as most oils are too thick when cold (even syntethic) so when the lift changed the oil did not get there quick enough, the use of esterbase oil takes care of the problem and it is expensive at 12 buck a quart even for the DIY crowd, the noise is only heard by very sensitive persons and it only happens once in a while, but if it is your toy, you will notice, so far there has been no reports of any damage from the use of regular oil and i have seen some engines with more than 50k miles on them