NissanMaxima
Thread starter
Thanks all. Valvoline has sent some pretty detailed replies. For what it's worth they say their full synthetic will not cause leaks or worsen exisiting leaks. To those here that are not fans of switching now to full synthetic, are you therefore comfortable with the MaxLife blend which Vavoline tells me contains ">15% synthetic base stocks"? In regards, to actually getting a better idea of sludge, I'm looking forward to the moment that front valve cover gasket is removed and getting a good look. Finally, as far as my concerns about cleaning, when I bought the car, I actually posted on the forum here a photo of inside the oil filler cap. It showed a black, almost crusty/oily material on a baffle-like looking plate below, that seems to remain an unsolved mystery. Unfortunately, you can't see below this plate. Some here (and I also read this on toyotanation.com) say that it is a black coating from Toyota, but others jumped to the conclusion it was sludge buildup, and others thought it was quite natural - condensed and hardened oil deposits since that area is cooler. The shop I had do a pre-inspection had no concern, but at the same time they tried to sell me on some items they claimed needed to be addressed which I think were perhaps exaggerated as to urgency.
Overall, I think the approach of sticking with the blend for now until gasket change does make sense, but if I had to take a gamble (and I don't even think it is that much of a gamble), that switching to their full synthetic with MaxLife will really worsen the exisiting small leak, but at the same time theoretically provide more protection and detergent power.
Overall, I think the approach of sticking with the blend for now until gasket change does make sense, but if I had to take a gamble (and I don't even think it is that much of a gamble), that switching to their full synthetic with MaxLife will really worsen the exisiting small leak, but at the same time theoretically provide more protection and detergent power.