Milk in valve covers

[Aaron Keown]

I have noticed that if we dyno on a day that it is raining the problem will be much more noticable.There are many things that can make this happen including just about every single one that the posters above me mentioned.IMHO the biggest reasons that this happens depends on the humidity and the fact that these engines just are not run long enough to prevent this from happening.A good example is if you have ever known an older person who will only drive their car to church on Sundays,everything on the car stays in excellent shape except for the exhaust system which will rust away in a year because the vehicle just is'nt run long enough to overcome this.This probably does'nt happen with new cars anymore since most of them have stainless or aluminized exhaust.