The 1100 motor in my van runs and pulls well and has no weird knocking or rattling noises.
Despite this, the oil pressure when hot seems too low (25psi at 2500 rpm and 15 psi at 800 rpm).
Upon startup, the cold oil pressure is 75 psi at 2500 rpm and 40 psi when idling at 800 rpm.
I had thought that the motor was buggered but would it still run and pull well even if the oil pump and or bearings were starting to go?
Does anyone know whether the above pressure ranges are within the normal limits or do I need to look at replacing the oil pump and or bearings?
Thanks
Dave

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Your imagination is only limited by the size of your wallet
"61 850 original and crusty (Mavis)
"64 Smooth Roof Van (Colin)
"67 Deluxe resto project (Monty)

That seems like a really large swing between hot and cold, I'm not sure what could cause this.

Just to add a bit of information for you, my '98 1275 which is in great shape, will startup with about 75 psi at 900rpm, up to about 95 at 2500rpm. Once warm, I sit around 50psi for idle and 65-70psi under load.

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1998 Rover Mk VII
2001 Honda CBR 929RR (street)
2014 BMW S1000RR (track)

they're pretty normal, but I reckon your oil is not up to the job

I'm very sorry in advance for turning your thread into a massive oil argument

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did I tell you that I won a trophy?

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1998 Rover Mk VII
2001 Honda CBR 929RR (street)
2014 BMW S1000RR (track)

Put some Valvoline XLD Classic in it.
If that doesn't help with hot pressure, your pump and bearings are on the way out.

I'd say any A series motor that can't give 40psi hot above 3000 rpm is overdue for a rebuild.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

My thoughts are main bearings. My 1100S engine was simular, ran strong and all but once it got warm the oil psi dropped.
Try a thicker, higher quality oil but like Doc said oil pump and or bearings may be the problem.

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Respect mine and I'll respect yours.

Thanks for the replies everyone.
I'll change the oil over to Valvoline XLD as the doc suggested and see what happens.
If this doesn't work, I've got a fresh motor lined up to replace this one (just wasn't keen on doing the job now!!)
Cheers
Dave

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Your imagination is only limited by the size of your wallet
"61 850 original and crusty (Mavis)
"64 Smooth Roof Van (Colin)
"67 Deluxe resto project (Monty)

The complicated answer is: How do you know how accurate your pressure gauge is? Is 75psi really 75psi?

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Lillee - 1969 Morris Mini K

Hi Lillee
Very good question and one that I asked myself as it would have been the simplest remedy if the only problem was a faulty gauge.
I removed the oil pressure gauge from my van and swapped it with the one from my daily driver (they have the same oil line fittings).
My daily's gauge showed exactly the same figures when installed in my van (DAMMIT!!).
Cheers
Dave

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Your imagination is only limited by the size of your wallet
"61 850 original and crusty (Mavis)
"64 Smooth Roof Van (Colin)
"67 Deluxe resto project (Monty)

Oh well it was worth checking. Imagine pulling the engine out and rebuild only to have it read the same!

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Lillee - 1969 Morris Mini K

I have an itsy bitsy teeny weeny SMC gauge that screws straight into the block. Very useful for checking oil pressure on lower class Minis that didn't come with a gauge.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.