I have noticed recently that it is taking about 7-8 seconds for the oil pressure to start registering on the gauge. Once it does it goes up to maximum at 1200 rpm. When hot the oil pressure is maximum from about 2,500 rpm. Is this normal? I would have thought it should start registering pressure almost immediately.
I am not sure that it has just started doing it or that I have only just noticed it. It is a 1.3S with an oil cooler. Recently I accessed the borttom end to check the bearings and the oil pick up pipe was removed. Is that a clue? Also an oil and filter change
Oil pressure build up
Re: Oil pressure build up
The 7-8 seconds for the pressure to register when cold seems abnormal. The rise to max pressure (~70 psi) at 1200 rpm seems normal due to the viscosity if you're using something like 20W-50. But I am a little surprised that it's able to achieve that pressure when hot from 2500 rpm. Typically that occurs at a little higher rpm.
My recommendation would be to first verify that the pressure sending unit is accurate i.e. substitute with a mechanical one which would also verify the operation of the gauge on the instrument panel.
If there was an issue with the pickup line i.e. possible air draw at connection, I would think you would loose pressure at high temps. What oil are you running?
My recommendation would be to first verify that the pressure sending unit is accurate i.e. substitute with a mechanical one which would also verify the operation of the gauge on the instrument panel.
If there was an issue with the pickup line i.e. possible air draw at connection, I would think you would loose pressure at high temps. What oil are you running?
Re: Oil pressure build up
Am using 10-40 semi synthetic and have done so for years.
I have just cleaned the relief valve by simply unscrewing the 22 mm nut and witdrawing the spring and squirting solvent down the hole. This has made no difference. I guess next step is undoing the 32 mm nut behind it and doing the job properly. I do have a spare (used valve and sender unit that I could try.
I have just cleaned the relief valve by simply unscrewing the 22 mm nut and witdrawing the spring and squirting solvent down the hole. This has made no difference. I guess next step is undoing the 32 mm nut behind it and doing the job properly. I do have a spare (used valve and sender unit that I could try.
Re: Oil pressure build up
I think I may have the answer to my delayed oil pressure build up. Reading the overhaul manual the oil filter base assembly has an anti oil drain back valve to keep the filter full of oil when engine switched off. If this is not working then the filter will have to refill every start.
I cannot work out where this valve is. I assume it is part of the relief valve mechanism but cannot work it out from the diagrams. I changed the oil filter recently and this problem has only happened since then. Can anyone help?
I cannot work out where this valve is. I assume it is part of the relief valve mechanism but cannot work it out from the diagrams. I changed the oil filter recently and this problem has only happened since then. Can anyone help?
Re: Oil pressure build up
It is a substantial filter so that's possible, but the max pressure reading at 1200 rpm would still be anomalous.
Does the filter you're using have a non-return valve? I've received both types when I have purchased new ones. Restarting after a short time should result in immediate pressure with a filter having a non-return valve.
Does the filter you're using have a non-return valve? I've received both types when I have purchased new ones. Restarting after a short time should result in immediate pressure with a filter having a non-return valve.
Re: Oil pressure build up
The anti drain valve is part of the filter.
We use MANN W-940/1
We use MANN W-940/1
Re: Oil pressure build up
Sorted,
Filter did not have anti drain valve although it was the same part as taken off. Bosch P4063.
Filter did not have anti drain valve although it was the same part as taken off. Bosch P4063.