I have a 2000 Jetta with 110,000 miles with a "refurbished" VR6 engine that i got from the dealer at 60,000 miles. The lifters have failed - the knocking sound is terrible and it barely can move. I've been told that I need a new engine (or a new car). Instead of scrapping this car or buying something else, I want to keep this one and put in a diesel engine - is this possible?