Anyone any ideas why my oil pressure would do this on a cold start?
750rpm 9psi
1000rpm 15psi
1500rpm 30psi
2000rpm 40psi
Once warm, settled on 30 psi at idle. Dropping gradually to 20 psi when hot. On Idle.
Next day, cold start.
750rpm 40 psi.
Dropping gradually to 30 psi when warm, 20 psi when hot. On idle.
The motor is a 4.6 RV8 with old style timing cover and oil pump.
Why would the oil pressure behave so differently on each day?
Oil pressure weirdness!
Moderator: phpBB2 - Administrators
Re: Oil pressure weirdness!
Relief valve stuck (partially) open on first test?
- Ian Anderson
- Forum Contributor
- Posts: 2396
- Joined: Sun Nov 19, 2006 9:46 pm
- Location: Edinburgh
Re: Oil pressure weirdness!
Had you changed anything?
Example just changed oil and not pre-filledthe filter, on startup it first has th fill the filter.
Just a thought?
Ian
Example just changed oil and not pre-filledthe filter, on startup it first has th fill the filter.
Just a thought?
Ian
Last edited by Ian Anderson on Sat Aug 14, 2021 10:13 am, edited 1 time in total.
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
-
- Site Admin
- Posts: 489
- Joined: Sat Feb 28, 2009 6:53 pm
- Location: Harpenden, Hertfordshire
Re: Oil pressure weirdness!
If it's anything like the electric one on the SD1, very likely.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
Re: Oil pressure weirdness!
It's an auto meter capilary gauge. Seems to make sense most of the time.
I think that as I was running straight SAE30 oil, the oil got too hot after some hard starts an the pressure dropped at idle. For some reason this may have also caused the relief valve to stick and give the weird readings the next day. Once it freed up, the pressure readings went back to normal.
I'm changing the oil to 20w50 and I'll see what happens.
This is a 4.6L with the old type timing cover, so it can run a dizzy, so it has the old style oil pump too.
I am also thinking I ought to fit an oil cooler. The air flow isn't great in a Minor!
-
- Forum Contributor
- Posts: 3979
- Joined: Sat Nov 18, 2006 6:22 pm
- Location: Northern Ireland
Re: Oil pressure weirdness!
Wouldn't waste time fitting a cooler, until you know what oil temps you are seeing
And use a proper oil, can't think why anyone would use an old single weight oil this century ?
And use a proper oil, can't think why anyone would use an old single weight oil this century ?
Re: Oil pressure weirdness!
The SEA30 was just to flush the old cr@p out, I had a drum of it to use up!stevieturbo wrote: ↑Wed Aug 18, 2021 7:40 amWouldn't waste time fitting a cooler, until you know what oil temps you are seeing
And use a proper oil, can't think why anyone would use an old single weight oil this century ?
I'll stick an oil temp guage in and see whats happening.