Jaguar XJ Supercharged VVT rattle-RennsportKC

This awesome Supercharged XJ came in with the same kind of rattle with the same kind of start-up rattle that led us to update the VANOS on the M5 earlier on the blog.   The dealer told the customer that it was the timing chain tensioners and that they were not covered by his extended warranty.  Well they are, and we’re getting this customer taken care of.

For many years the Supercharged Jags dropped the VVT that was on the N/A cars.  In 2009 it is back and looking just like the ones on the NA motors since 2000.   When these leak down they can  cause the same sort of rattle.  Jaguar has been doing his oil changes and there are a few problems with that.  First is the conventional oil that they use.  Second is the 10,000 mile change interval.  Third is the 5000 miles over that this car ran before its last service.  ANY sludge in these motors will keep the ball valve from seating and keeping tension in the system so our first step is to change the oil to a good quality synthetic and see where we really are.