Not had my Series III long but thought I'd change the oil and filter. It's done 150k miles and isn't noisy or rattly and I want to keep it that way !

Soooo, who uses what and is there anything I should know or is it a straightforward enough job ?

 

20/50 is the favorite of virtually every Ser III owner.

No tricks to speak of; nothing out of the ordinary about the job. Get a filter ahead of time as not every corner auto parts shop keeps Jag filters on-the-shelf.

Cheers
DD

 

That'll do nicely. Cheers Doug

 

gee that was short and sweet, I was expecting the viscosity/synthetic/mineral wars to break out

 

I just had my oil done last week. I was talked into Brad Penn semi-synthetic. It had high zinc, which my classic car mechanic swears by. I may have been slightly swayed in that it was made in Pennsylvania, my home state!

 

no synthetic "oil", Mineral oil ONLY.

and specifically Castrol 20W50.

you know the saying, "Pay Now or Pay Later".

 

Synthetic Oil leaks better out of these engines too

 

As far as I remember, in the 80s Jaguar also recommended 15W40, which I used to use. I had no ill effects and I had the car 14 years.

 

Jaguar actually recommended a variety of weights depending on temperature....and there was some overlap. 15/40 was one of the approved weights. Everyone seems to have settled on 20/50. It works well for all conditions until you get into freezing temps or lower.

Jose mentioned Castrol and that, too, has been a favorite of many. There's something about Castrol and Jaguar that goes back decades....and it just sorta stuck. They just go hand-in-hand. It might go back to the racing days of the 50s. A week's pay says the Castrol of today is nothing like the Castrol of 30-40-50 years ago but, if a person is into sentimental favorites, that's the way to go. If you check that manuals, however, Castrol is just one of several brands approved by Jaguar.

The synthetic debate will always rage on. For most of us I'd say that using synthetic has more 'feel good' benefit that real world benefit. I see no reason to avoid it, though, if it makes you happy.

Someone mentioned higher zinc content. Now that's something worth watching for. It's likely of more real world significance than brand name or dino oil versus synthetic oil

Cheers
DD

 

Does it make a difference if the engine has been rebuilt recently (2-3000 miles).

I must admit I would prefer a semi synthetic, for peace of mind, but wouldn't like it to leak especially as I gather the rope seals at the rear crankshaft is prone to this.

If I tried it and it leaked would it have caused any harm or could I just go back to mineral oil after?

 

Won't harm anything.


Cheers
DD

 

A very debateable topic. Higher levels of zinc are generally favoured (~1200 ppm). Generally speaking for our "flat tappet" engines one would want around 1200 ppm of ZDDP (commonly referred to as zinc) this is an anti-wear additive that has been reduced to around 800 ppm by the government (API-SN approval) for the sake of "greener" exhaust gasses and catalytic-converters.

IMHO I would look for an oil containing a higher amount of ZDDP (not approved to meet API-SN). Another option is to look out for oil additives containing ZDDP or containing something with a similar effect.

Not meaning to confuse anyone, hope this helps.

Nathan

 

The Brad Penn Oil that my mechanic swears by rates around 1500 PPM of Zinc. He uses is exclusively on older Porsches, his specialty. Apparently, it's a remarketed version of Kendall Oil GT1.

I don't claim to understand any of this, but it did seem to have favorable ratings on many vintage car websites.

 

Right.

At work I use ZDDP on the old cars. It's so simple to add it to off-the-shelf oil and be done with it.

ZDDPlus | Maintain proper ZDDP levels in your engine

I'm not 100% convinced it is necessary....but it's so easy that it seems a shame not to do it.


Cheers
DD

 

Never give up hope.

You may have just done the opposite.

The bucket-and-shim OHC engines as used in Jaguars of the era are not comparable to 'true' flat tappet OHV engines (ex. Gen 1 Chev SBC) in terms of requirements for ZDDP.

The 800 ppm limit in today's API SM and later oils is more than enough.

Fact is, 800ppm is more than enough for almost any stock OHV flat tappet engine as well. That was the typical ZDDP content in oils of the 50s and 60s when Ford, Chrysler and Chev brought their V8s to the market. It was only in the late 60s as a result of the muscle car era when high ZDDP oils introduced. Unless you've got an LT1 or L79 under the hood, SM oils are fine.

Any mechanic who insists on boutique oil brands or anything with 1500 ppm ZDDP is obviously misinformed and would lose my business instantly.

 

The whole thing seems to have started 10 years ago or so when some engine rebuilders were seeing major engine failures *immediately on first start-up or during the initial break-in period*

It's a bit like the E10 debate.

If things were really as bad as the ballyhooers tell us, our roads would be fully lined with broken down cars.

Cheers
DD

 

Right!

I've never used any of the ZDDP additives in my Jags.




Which is why I use the ZDDP on the cars at work . Even then, I question myself at times. It's just that I'd hate to explain a lubricity failure when the possible prevention was so easy and readily available.


Cheers
DD

 

True enough. It's been argued with a significant degree of truth that the root cause of the cam failures was the poor quality of certain aftermarket manufacturers. There is also the tendency by some rebuilders to automatically install cams with outrageous lift and duration numbers along with all sorts of other boy-racer stuff.

Maybe it's the Satan E10 after all?

BTW- I took apart the carb on a 35 year old outboard the other day. It's had nothing but E10 for the last 20ish years. Clean as a whistle. Fuel lines were as flexible as if they were installed yesterday. The motor has been in the family since new so I know exactly how it's been used and maintained. Aside from running the engine dry of fuel at the end on the season, no special precautions were used.

 

Certainly gives me peace of mind, I'm doing my first oil and filter change tomorrow. I've got an oil that contains MoS2, also used for wear reduction. Personally I like to go for the best that my wallet will allow me each to his own though.

Nathan

 

I've used Valvoline or CARQUEST