Oil pressure

Clifford Pope · May 14th, 2004, 09:21

For the last 296,000 miles the oil pressure light has flickered on at idling speed, but goes out as soon as the revs increase.
I have the service records, and I see that from new (1993) Volvo agents periodically fitted new pressure senders, to no avail.
Now at last I have got round to measuring the pressure with a gauge, and I find that with the oil hot, it reads 5 psi at 800rpm, 7 psi at 900 rpm, 20 psi at 1500 rpm, 30 psi at 2000 revs, and peaks at 40psi at 3000 rpm.

I have almost resigned myself to getting the sump off this weekend and replacing the oil pump and O-rings, but am put off by the difficulty of gaining access.
Is the pressure OK for a bit, or would it be sensible to take corrective action now? The engine seems in good condition - no knocks, ticks or rattles, doesn't use oil, just passed its emissions test easily.
Any tips on raising the engine, lowering the cross-member? What about the attached brake pipes?

I have done this once before with the older shallow sump, but even that was not easy.

What do others think?

neil stevenson · May 14th, 2004, 10:08

If it is not broke, don't fix it.

Seems well enough as it is.

Ensure oil is changed regularly and use a good filter.

Clifford Pope · May 14th, 2004, 13:15

Thanks Neil - that's what I wanted to hear!
I had just wondered how near broke it was though.
I have always changed the oil every 3,000 miles and the filter every 6,000.

Clifford Pope · May 15th, 2004, 13:59

Well, in the event, after noticing that the oil pressure was actually a little lower than I thought, I went ahead and replaced the pump this morning.
It was not such a difficult job as I feared - I devised a way of getting the sump off without having to drop the cross-member.
The cause of the low pressure was immediately apparent - the rubber seal in the pipe from the pump to the block was displaced and bulging out exactly like the picture on Brickboard. Both seals were hardened and crumbled as I withdrew the pipe. Having got so far it seemed sensible to replace the pump, in view of its high mileage and unknown condition.
The result is a dramatic restoration of oil pressure - from 10 psi at cold idling it is now 60. I don't know the hot figures yet, but they are bound to be an improvement.

I am going to write up an article for Volvo Technical Driver, so watch that space if you want to know the details!

neil stevenson · May 16th, 2004, 17:16

Should be good for another 200,000 miles now.

May 14th, 2004, 09:21	#1
Clifford Pope Not an expert but ... Last Online: Apr 26th, 2024 12:45 Join Date: Dec 2001 Location: Boncath	Oil pressure For the last 296,000 miles the oil pressure light has flickered on at idling speed, but goes out as soon as the revs increase. I have the service records, and I see that from new (1993) Volvo agents periodically fitted new pressure senders, to no avail. Now at last I have got round to measuring the pressure with a gauge, and I find that with the oil hot, it reads 5 psi at 800rpm, 7 psi at 900 rpm, 20 psi at 1500 rpm, 30 psi at 2000 revs, and peaks at 40psi at 3000 rpm. I have almost resigned myself to getting the sump off this weekend and replacing the oil pump and O-rings, but am put off by the difficulty of gaining access. Is the pressure OK for a bit, or would it be sensible to take corrective action now? The engine seems in good condition - no knocks, ticks or rattles, doesn't use oil, just passed its emissions test easily. Any tips on raising the engine, lowering the cross-member? What about the attached brake pipes? I have done this once before with the older shallow sump, but even that was not easy. What do others think?

May 14th, 2004, 10:08	#2
neil stevenson Senior Member Last Online: Jun 6th, 2017 14:09 Join Date: Oct 2000 Location: Carrowdore	RE: Oil pressure If it is not broke, don't fix it. Seems well enough as it is. Ensure oil is changed regularly and use a good filter. __________________ Neil Stevenson 2000 S40 1600cc. 940 SE Turbo Estate.(sold).

May 14th, 2004, 13:15	#3
Clifford Pope Not an expert but ... Last Online: Apr 26th, 2024 12:45 Join Date: Dec 2001 Location: Boncath	RE: Oil pressure Thanks Neil - that's what I wanted to hear! I had just wondered how near broke it was though. I have always changed the oil every 3,000 miles and the filter every 6,000.

May 15th, 2004, 13:59	#4
Clifford Pope Not an expert but ... Last Online: Apr 26th, 2024 12:45 Join Date: Dec 2001 Location: Boncath	RE: Oil pressure Well, in the event, after noticing that the oil pressure was actually a little lower than I thought, I went ahead and replaced the pump this morning. It was not such a difficult job as I feared - I devised a way of getting the sump off without having to drop the cross-member. The cause of the low pressure was immediately apparent - the rubber seal in the pipe from the pump to the block was displaced and bulging out exactly like the picture on Brickboard. Both seals were hardened and crumbled as I withdrew the pipe. Having got so far it seemed sensible to replace the pump, in view of its high mileage and unknown condition. The result is a dramatic restoration of oil pressure - from 10 psi at cold idling it is now 60. I don't know the hot figures yet, but they are bound to be an improvement. I am going to write up an article for Volvo Technical Driver, so watch that space if you want to know the details!

May 16th, 2004, 17:16	#5
neil stevenson Senior Member Last Online: Jun 6th, 2017 14:09 Join Date: Oct 2000 Location: Carrowdore	RE: Oil pressure Should be good for another 200,000 miles now. __________________ Neil Stevenson 2000 S40 1600cc. 940 SE Turbo Estate.(sold).

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