My local Jaguar mechanic (Italian and British car repairs since 1975) brought up an issue about oil brands and viscosities. He said he always used Castrol in the past but now days most oils have had a lot of the additives removed as they can contaminate the catalytic converters on newer cars. He said the additives protected the camshafts and tappets, but aren't needed with the roller tappets and cams used in many modern cars. He has heard of people having problems with wear to the camshaft caused by the newer oils. He now often uses Shell Rotella T 15W40, which is actually a diesel oil.

I did a little research and read that the additives were zinc and phosphorus and that the oil ratings changed from SL to SM for gasoline engines and from CI-4 to CJ-4 for diesel engines when the additives were removed. (Some of the Rotella oils have converted to the CJ-4 formulation but the 30W and 15W40 in the 2.5 gal jug are still CI-4).

The plate on my car lists the following summertime oils; Mobil A, Castrol XL, Shell X100 30, Esso Extra 20W30, BP Energol 30, Duckham NOL 30 and Texaco Havoline Advanced 30. Obviously, several of these aren't even available and I don't know what specs. have changed.

I'd like to know if other owners of older Jags have heard about this, if any have had camshaft problems, and more importantly what brand, type, and weight of oil they are using.

Thanks,

Jim Klekas
68 E-Type OTS
Salt Lake City, UT

Submitted by jklekas@aol.com on Sun, 08/07/2011 - 12:55

Frank,

Thanks for the information on Brad Penn Penn Grade 1 Oil. The link you provided makes for great reading on the issue of zinc/phosphorus in oil.

I suggest anyone with the same questions I've had check the Zinc Phosphorus link and the 7-18-11 ZDDP Report on the Technical Reports link.

Again I thank everyone for their input.

Jim

Submitted by bonnettoboot@e… on Sat, 07/23/2011 - 22:08

Hello Jim, yes there is truth to what you have heard, the refiners reduced or eliminated the zinc from oils as it tended to block the cats. At this point it is unclear just how much flat surface tappets -such as yours- will be affected. It took years for most people to find out about it and I havent heard of a failure due to it. Nevertheless I for one use a RACING oil - valvoline- (these oils were exempted from the change), there are many on the market, and they have high zinc levels and are probably a better oil anyway. Some people early on used diesel oil as it still had the zinc content.