Originally Posted By: BlueOvalFitter
My g/f's 1999 Malibu has 220K miles on it and has an oil leak. We just had an OCI with 10W30 Synthetic VML. The engine usually goes through a qt. about every 1500 miles.
By using an HDEO oil in it, will it slow the leak down? If so, what weight and brand would one recommend?
First of all if you can fix the oil leak for a reasonable cost that would be a real good idea.
HDEO oils were designed for diesel engines although most can be used in petrol ones. They contain a higher amount of Zinc based additives than normal oils and that can be an issue for the life expectancy of a CAT unit. They also contain a fair amount of detergent additives.
It you don't fix the leak then just use the cheapest Wallymart 0 or 5w40 that has the correct API specs, as moving up one grade might reduce your oil consumption. Using a high mileage (HM) oil should help reduce the oil leak rate, or you can try using a can of major brand oil stop leak additive. Liqui Moly Motor Oil Saver is probably the best one, although Lubegard also make some good oil additives.
Make sure the crank case vent has not been blocked (Google balloon test) by sludge as that will push oil past the seals fairly quickly. It's rare for a CCV to block if you use a good major brand oil changed at sensible intervals as that will prevent sludge deposits.