Are Northstar engines having a problem with oil leaks?
While I have seen some oil leak repairs being done at my dealership, I certainly would not say that there is a high incidence of oil leaks from Northstar engines. To the contrary I think there is probably a considerable decrease compared to previous engines that Cadillac has produced over the last 10 years. Maybe the reason there has been any discussion is because of the expense involved in repairing one particular seal failure between the block sections. The Northstar is constructed in 3 sections, with an o-ring seal between the sections. First there is an upper and middle block and then the lower block which many call a pan on other engines. The expense is the result of the fact that engine must be removed to service the o-ring seals especially between the upper and middle sections . There is some research that suggests that poor maintenance of the PCV valve may increase the rate of seal failure. The PCV helps release internal block pressure and it makes sense to me that this could c
