Oil press excessive?

(PeteWilletts) #1

My engine idles at about 40 psi and is pegged at 60 when above 2000 rpm,been this way for some tine…switched original canister for screw on with no real change,could examine bypass valve I suppose

(69 FHC ) #2

Are those cold or with the engine fully warmed to normal operating temperature (NOT) numbers?

Mine does the same but hits about 30-35 at idle and 55 at 2500 rpm when the engine is at NOT.

(Terry Sturgeon) #3

The pressure relief valve in Ser 1 cars was set at 40 psi, so you should not exceed that at 3000 rpm when fully warmed up. Later XK engines, in particular at some stage in the XJ6’s they raised the spring to 60 psi, and the engine should run there at higher RPM’s. Is it possible that somebody has switched oil filter blocks?

(Roger Benjamin) #4

my 4.2 runs exactly 40 psi and 60 psi. makes me feel good!

(Paul Breen pay palled it) #5

My '72 XJ6 runs higher than standard - about 65 psi hot also high at idle. My '63 e type runs about the same - never falls below 45 psi at idle. Both have Series 3 pumps and filter heads and both are low mileage rebuilds. I fitted a 100 psi (full scale) mechanical gauge in the e type. Not knowing the upper limit of pressure with a 60 psi (fsd) gauge made me uncomfortable. XJ6 gauge runs to 80 psi. Paul

(Paul Wigton) #6

Jag factory numbers are 10psi/1000 rpm: any more than that is unneeded.

(David Jauch) #7

Probably not even that, considering that they used to set the relief to 40.
my XJ S3 opens at 45. Probably age related, I could put in a shim but then again it is sufficient.

If it idles at 40 on a really hot day after 20 miles minimum it might start to be strange. But if the cams see oil at idle and it still runs today and has been for some time it must be alright… right?

The question is if something had changed at some point. In this case I‘d check with a mechanical gauge.

(David Ahlers) #8

Pete, that oil pressure isn’t on a notoriously inaccurate OEM E type pressure gauge/sender, is it?
Verified with a mechanical gauge (I hope not)… Then it might not a real issue if its on the standard gauge.
I’m at 45psi or so hot at running rpm. 20ish at hot idle. Mechanical gauge.

(Paul Wigton) #9