4.2 oil pressure

[moggybrian]

What is the recommended oil pressure for a 4.2 injection engine (1983)
all units, sender etc,
changed I suspect the dash gauge?
runs at 40psi day and night?
with slight loss of pressure when really hot,
on a long journey!
mogB

[mike020150]

The 6 cylinder XK engine runs at a nominal minimum 40psi at 3000 revs (hot). At hot idle, the pressure drops to 20psi or less. Checking it with a 'wet' gauge, i.e. screwing a pipe in place of the sender to an accurate mechanical gauge is the only way to be certain. Later model Jaguar oil pressure gauges were made to operate more like on/off switches and only read a single figure or zero. However, I would have thought that change occurred somewhat after 1983. Mike.

[oldtimer]

Hi Mog,
I agree with Mike above in every detail.

Has been forever thus, back to pre historic times, I know I was there

Oldtimer

becoming very old timer

[vernon]

Hi, mogb,
I have a 1985 4.2 efi that has just been re-built, re-bored etc.
My oil pressure is 40 -55 psi above 1000 rpm and 25 - 30 at tickover when hot.
Before the rebuild it was 15 at tickover and it took 3000 rpm to get to 40 psi when hot.
The oil pressure guage fitted to these engines is well known for its inaccuracy, so is the sender unit.
I've had 3 senders and 3 gauges before I got a reliable result.
You can get a matched sender and guage for a more accurate reading, but a wet guage is the answer for real accurate readings.
Hope this is of some help.
Vernon

[moggybrian]

Thanks Guys,
Thank goodness!
mine sounds about right,
but you are all right about the senders!
they are 'c--p',
Paul who looks after jag' for me says the series3 has always had
problems with oil pressure readings,
looks like MORE sender units.
meanwhile,
Thanks again
PS: in bodyshop at present having 'screen apertures' done!!!!!!!!!!
MogB