Oil pressure reading

[KINGPRAWN]

Just got my vdo gauge setup working(excluding oil temp) and on initial start up the gauge read 3.5 bar even at idle, but 2 miles up the road it dropped right off. Now idles at 1 bar and goes up to 3ish is this as it should be??

[Footprint]

The gauge will always read high when you start from cold, the oil will be thicker then thus harder to push through the system, when the oil heats up and thins out the reading will inevitably drop.
I'm not sure of the exact pressure requirements of your engine as I don't know which you have, but, as a guide the specs for my 2.0l aircool are; oil temp of 70C, straight 30W oil, engine speed 2500rpm, oil pressure should be 42psi, (2.9 bar), with a lower limit of 28psi, (1.9 bar).
So, making the leap that you've got a flat four engine, and your gauge is reasonably accurate, those numbers sound OK.

Of course that could all be rubbish, as you might have an entirely different engine!

[KINGPRAWN]

Thank you...i have a 2.1DJ. but those numbers of yours don't sound too different:D

[PetenAli]

Hi Andy. I think you can work on 1 bar per thousand rpm (at normal running temp) as being about right - so yours seems OK. Where have you fitted the sender?

Pete

[KINGPRAWN]

I'll pop by some time and show you ... Oil temp still a work in progress!!!

[KINGPRAWN]

Well ... Apart from the initial start up and a quick couple of miles up the road today was my first real journey . With the enging at proper operating temp but not showing any sign of being remotely on the getting a little hot stage( temp needle just under half way between zero and the little red light) at idle the oil pressure reads virtually nothing and at 3k rpm 2bar at best! Is this normal? how good is a vdo gauge? Do I have a problem??
The oil and filter are spanking new from brickwerks.
As I have mentioned earlier on cold start up I get nearly 4bar running and 3/3.5 at idle!
It runs and has been running perfectly but going back to the start of this project my death buzzer would complain if I kept it at bit of a push on the dual carriageways ???? Any ideas , solutions or comparisons greatly received!!!

[kevtherev]

My wet gauge reads 15 psi hot at tickover
it reads 60 psi (4.1 bar) cold at tickover and at 3000 rpm

it reads 40 psi (2.7 bar) at 60 mph (3000 rpm) (hot)

your buzzer is lying unless your oil is foaming in the sump

without a direct type of reading to compare it to... you will always wonder if it's right

[KINGPRAWN]

My wet gauge reads 15 psi hot at tickover
it reads 60 psi (4.1 bar) cold at tickover and at 3000 rpm

it reads 40 psi (2.7 bar) at 60 mph (3000 rpm) (hot)

your buzzer is lying unless your oil is foaming in the sump

without a direct type of reading to compare it to... you will always wonder if it's right

After all the fuss getting the thing to work its causing me more anxiety with information than without!!!

[kevtherev]

Worry gauges made me proactive rather than reactive
..and you want to fit a temp gauge
I would hope you verify the readings if you are in doubt.

Not long ago my buzzer went off and the red light started flashing
A full house, but a glance at the pressure gauge steadied the nerves. It was bang on 40 psi.
Turned out to be a poor connection on the high press sender.

To keep my pressure up I will be fitting an oil cooler as I have noticed on longer trips the pressure drops at high speed (30 psi) But first Ill address the probable fault in the blocked rad

[KINGPRAWN]

Thanks kev... I do have an oil cooler to fit and an oil temp gauge, but I've been putting off fitting the temp sender as I have to remove the silencer... So don't want to do that but I guess it's a must!! I have the 2.1 DJ that died have an oil cooler but how good it is....?????

[KINGPRAWN]

Just doubled my oil pressure by changing oil... Was using Fuchs 15/40 with tragic oil pressure ... Now using Mobil 10/60 (synthetic).... Did I do a bad thing?????

[axeman]

in my old 2.1mv which was a warn engine, i was using a castrol 10/60 with very good results oil pressure wise there was an increase in the o/p reading through out the rev range. the whole oil debate was revisited a while ago when adian posted up very positive repots on his experience with his high milage mv using a synthetic oil,
in my opinion there is no point in using mineral oil, you have done no harm to your engine by swaping from one type of oil to another,

neil

[AdrianC]

I have the 2.1 DJ that died have an oil cooler but how good it is....?????

It's an oil-water cooler, rather than oil-air, so it "tries" to keep oil and coolant temps the same. Whilst that's not a great problem - the coolant should be about 90degC, which is a nice temp for the oil, it won't do much to take excess heat out of the oil in a hurry, because there's only a small difference between the two, so the heat transfer's going to be limited by that.

What it will do fairly well is to heat the oil up more quickly from a cold start - which an oil-air cooler won't.

[KINGPRAWN]

in my old 2.1mv which was a warn engine, i was using a castrol 10/60 with very good results oil pressure wise there was an increase in the o/p reading through out the rev range. the whole oil debate was revisited a while ago when adian posted up very positive repots on his experience with his high milage mv using a synthetic oil,
in my opinion there is no point in using mineral oil, you have done no harm to your engine by swaping from one type of oil to another,

neil

Thanks Neil... Since fitting the gauges with lot of help from yourself the extra info has left me scared to death of engine failure... All is well now... I hope

[kevtherev]

I have the 2.1 DJ that died have an oil cooler but how good it is....?????

It's an oil-water cooler, rather than oil-air, so it "tries" to keep oil and coolant temps the same. Whilst that's not a great problem - the coolant should be about 90degC, which is a nice temp for the oil, it won't do much to take excess heat out of the oil in a hurry, because there's only a small difference between the two, so the heat transfer's going to be limited by that.

What it will do fairly well is to heat the oil up more quickly from a cold start - which an oil-air cooler won't.

It will if you fit a thermostically controlled one.
Which Mocal do