Hi guys,
I have an 85 3.6 manual XJ-S. What is the correct oil pressure? The photo is after a long drive when the car is stationary. Where should the oil pressure be? And where should it not be?!?!

Thanks in advance

 

Oil pressure fine. No need to worry unless the light comes on! Jaguar got so fed up with owner oil pressure paranoia they changed the gauge sender to always read a decent pressure!

 

Thats naughty of them! Thanks for the info.

 

Hi,

As Greg says your oil pressure looks good.

My 1990, 3.6 has 138,000 miles on the clock. At cold start up tickover is about 75 psi but at normal temperature the gauge sits pretty much were yours is at tickover. Driving when fully warmed up pressure sits at about 60 psi.

Your temperature gauge is spot on to. Should sit about half-way between C & N. If it sits on N the engine is running too hot.

Cheers,
LeeP

 

Later Jaguar gave up the good fight with temperature gauges as well, modifying them to read 'normal' over a wide range of temperatures, to assuage needless worry. Other manufacturers have done the same.

This practice isn't so bothersome with the oil pressure gauges....given the rarity of oiling system failures and internal engine faults. With respect to the coolant temp gauges....well.....maybe, maybe not.

Cheers
DD

 

Given the notorious inaccuracy of the barrel gauges I'd be reluctant to make that assertion, personally. But even if we assume accuracy, a "middle" or "N" reading reading on any temp gauge would typically be considered normal or safe....and it wouldn't be unreasonable to think of a lower reading as too cool.

Cheers
DD

 

when I first got my jag I drove it with eyes firmly on gauges and a spare pair of underpants in the glovebox. Sitting at a T junction waiting to turn I saw the oil pressure fall to zero, with no oil light on I changed underwear and limped home thinking "what have I done buying an old jag". However the oil pressure came back up and everything was ok. I changed the battery because the old one refused to hold charge and since then the oil pressure hasnt fallen to zero, so I surmise that the gauges need a reasonable amount of voltage to operate properly. those barrel gauges however are complete "whats the word Im looking for "

 

I must be lucky as I find my temperature barrel gauge very responsive having sorted out various cooling system problems including a new water pump. It now reacts to a climb up a steep hill by rising slightly and then falling slightly on downhill stretches from its normal resting position half way between C and N.

Thanks to Leo for reminding me what is missing from my tool box - a spare pair of undies!

Cheers all,
LeeP

 

TSBs for the oil gauge.

 

Looks like your alternator isn't charging completely, Duke.

What weight oil are you using? My AJ6 has 10W40. I have read that the six likes 20W50?

 

Can I share some experiences with my car, a 68 4.2 converted to triple su's and ignition timing set to S1 specs? On a hot day while idling at 700 rpm, the pressure sometimes drops to 20 psi. This is with 10W40 oil. I have calibrated the measurements by connecting the sender to an air compressor and the agreement was surprisingly good.

Many (including me) might be alarmed. However, these results have been consistent over the past 53 years and 75k miles that I have driven the car. In addition, the engine was torn down and rebuilt 4 years ago as part of a restoration and there was no indication of excessive wear. I had planned on replacing the main bearings along with lots of other things but they were pristine and left in place.

After the rebuild and some fettling the engine runs better than when new thanks to the carburetor changes. So I keep on driving and still get concerned when the pressure drops but I guess that's the way it is. Thoughts anyone?

 

You need diapers. Great story though