I've got about 184,000 km on this car. The oil looks relatively clean and it has a new looking oil filter. My question is, how do I tell if the oil is synthetic? It has a "Parts Master" oil filter. Is this any good?

What oil filter do you guys use for your 4.0 litre inline 6?

Mike

Welcome to the forum, Anbran. I stock whatever looks like the best deal on RockAuto. Lately that's been Motorcraft, although I have also used Bosch, as well as some other, lesser known and unremembered brands.
Short of sending a sample off for analysis, I don't know how you could distinguish whether or not your crankcase is housing synthetic oil or not. I further don't know why you'd care?

An excellent practice, if you've just acquired a 20+ year old car, would be to renew all the fluids so as to establish a baseline, unless you have documented maintenance history. FWIW, the 4.0L, as well as several Jaguar Techs, seem to like 15w-40 (5w-40 in syn) though you will find opinions on oil and oil filters are nearly as plentiful as rectal sphincters in any population of forum participants.
All but the hard-boiled brand ambassadors will agree that new, clean oil, changed at the recommended intervals, will result in a long-lived AJ-16 irrespective of brand and viscosity rating within reasonable parameters.

Napa auto parts has the right filter if you need one today (and if you have Napa wherever you are!). Napa brand #1231. Made by Wix, a reputable mfr. Costs more than the Rock discount items, but no shipping charges!

At the risk of poking a stick into a hornets nest, my only input re viscosity is to pay attention to the Jaguar recommendations for your climate. There is sometimes a temptation to put “thicker” oil in because the engine is “old” and will be worn. In fact a well maintained AJ16 will evidence very little wear, and these engines were designed to run on relatively “ thin” modern oil.

Hi Anbran,

Welcome to the Jaguar Forums! It's great to have you with us!

Ditto on countyjag's advice to follow Jaguar's oil specifications. Your car was manufactured a decade before Jaguar began specifying synthetic oil, so you can use conventional oil (which I personally prefer in the AJ16, but I don't judge those who want to use synthetic).

Rock Auto usually carries the Mann W7197 and Mahle OC238 oil filters. Mann and Mahle are long-term original equipment manufacturers (OEMs) for Jaguar. The Mann is the same filter you will get at a Jaguar dealership without the Jaguar graphics. I usually order 2 or 3 Manns at a time to reduce the per-filter cost of shipping.

The Wix 51231 is also excellent and Wix is now owned by Mann+Hummel.

Two very important features you want in an oil filter are a check valve or non-return valve, which helps keep the oil system primed, and a bypass valve, which allows oil to flow should the filter become obstructed. The Mann, Mahle and Wix all have these features.

Cheers,

Don