Oil pressure

[TrRob]

When the engine is cold, running idle the oil pressure gauge reads about just over the 50.

When the car runs for about 20 minutes the reading is the same.

After about an hour the the reading seems normal (low pressure) when idle or running slow,

when runing the pressure is just over the 50.

I always thaught that with an cold engine an running idle a low pressue is normal.

thanks Rob.

TR4A '66

Edited May 30, 2013 by TrRob

[peejay4A]

Higher idling oil pressure with a cold engine is normal.

[BlueTR3A-5EKT]

Factory I think said.

 

70 psi at 2000 rpm with the engine at running temp.

 

I have always used that as the bench mark

 

Peter W

[Ashley James]

Mine with a reground crank etc is about 25 psi at about 700 rpm and 70 at just over 2000, so pretty much what the book says, which I think is 60-70 at 2000 when as hot as it gets.

[wayne taylor]

30 and 90 (idle and 2000revs)

[Ashley James]

30 and 90 (idle and 2000revs)

You probably need to back that off a bit, which is what I had to do. 90 is a bit high.

[ianc]

Ashley is correct - 90 is too high and there is a risk that oil seals will blow.

70 is what the book says, and one should stick to that as a maximum.

It's oil FLOW that really matters because it is the flow which takes the heat from the bearings and dumps it in the sump. I'm quite happy to see an oil pressure of 50-60 when the engine has warmed up and I'm motoring briskly.

Ian Cornish

[ChrisR-4A]

Mine is also about 60 @ 2500 rpm when well warmed up but 65 to 70 for first 30-50 mins depending on speed. Driven on A/B roads at speeds up to 55 can take over an hour to be warmed up completely but after an hours stop for lunch its back at 70 for first. 1/2 hr , whereas using motorways at speeds up to 75 it can be warmed through in 30 mins. Fully warmed up tickover at 800/900 rpm is 25/30. Engine has done nearly 5000 since rebuild 16 months ago.

[TrRob]

Maybe I shoud check the thermostat or consider to put another in to get it faster hotter?

[ChrisR-4A]

Summer may fix it ?

[Ashley James]

Summer may fix it ?

You're optimistic!

 

It's simple enough to undo the lock nut on the oil pressure relief valve, screw it out half a turn, try it and if it's still high, try another half.

 

Somewhere around 60-70 at around 2000 is fine, you can't be that accurate because all the gauges aren't.

[wayne taylor]

How does one 'back the oil pressure off'? I haven't done a 1000 miles since a complete engine and gearbox rebuild, so maybe it will calm down of its own accord?

[Ashley James]

Wayne

 

If you look just behind the distributor at the top of the oil filter housing you'll see a big lock nut and a stud going through it with a screw driver slot in the top. However if you're non technical best take to someone who is to sort it because a mistake could be expensive.

[wayne taylor]

OK: 30 psi @ tickover. 85psi @ 2000 and 90psi @3000.

 

Found the relief valve screw - which way do I turn it to decrease the pressure and by how far?

[Ashley James]

Wayne

 

Having undone the lock nut I'd unscrew it anti-clockwise 1/2 a turn and try it and if it's not enough then another half a turn.

 

I'm guessing one turn will be required and Stuart may advise as he's an expert, but best proceed cautiously.

[stuart]

They all respond differently so its really a case of mark it before you start and make a note of how far you turn the screw. As Ash has said unscrew to lessen and screw in to increase. You need to use a ring spanner on the nut and dont forget to lock the nut off after you have finished. All measurements must be done hot.

Stuart.