Royal Purple has a product made just for our diesels. It is a great product.

The truck gets better mileage, and is ten fold more quiet than with regular oil. Also, synthetic oil does not "mix" with water, so if there is a problem oil still gets to the important parts.

The oil is not the problem, it has to do with the filter, or rather the filter gasket, or the way it is mounted.

It did the same thing when I used to run Delo 400 15W-40 in it.