Thread: oil pressure issues still...

Lots of ideas, but sadly you're going to have to go looking yourself.

Persistent low oil pressure can only be a result of:

Worn pump gears - you've replaced them, but not all gears are equal. There are some SHOCKING quality parts out there for sale.

Worn pump housing - check the side clearance of the gears within the pump housing, and verify the cover plate is not scored.

Wrong gasket between pump housing and cover plate. I've had gaskets ranging between 0.24mm and about 0.11mm and there's a huge difference in pressure.

Failed timing cover gasket - but I'd expect that this would be a problem that suddenly emerges and gets far worse in short order. Only way to check is to check. Been there and hated that.

Excessive clearance in mains, big ends, cam bearings or rocker shafts - the only way to check these for certain is to CHECK these.

thanks for the reply.
the gears seemed to be of good quality 'meshed' well and cleared the teeth smoothly.
Housing has slight scoring but nothing bad.
gaskets supplied with kit were wrong, first time i was lazy to my demise and didn't check for free spinning, they gears where jammed so it broke the dizzy drive .

I ended up using 0.5 and 0.1 on the spacer this was the tightest i could get without the gear binding, they're move but not 'free spinning'.

the timming cover gasket could be it. I replaced the cam, tappets etc last year whilst I was at a mates place in Brissy. drove home & a month or more later is when the problems first started.

It's a mucky, annoying job to do the timing cover gasket, but look at it this way. Drive the engine as it is and it will be toast. If you want to check any of the other clearances you'll be doing the gasket anyhow. You might be lucky and find it's the cause before you have to go further.

Depending on how vigorously you're prepared to be in chasing the cause before you change engines, taking the rocker covers off will allow you to observe how much oil is bleeding past the rockers as you drive the pump with a drill from where the dizzy would normally be. Same goes for the valley gasket if you're game to go that far - you'll be able to observe the cam bearings and have some view of the main and big end bleed rates.

Which gauge are you reading off?

The one thing not mentioned is checking the sender unit (if it's an elec gauge). If it's the original smiths gauge then I'd look at the sender.

It seems really strange to me that it will idle on 20PSI cold then not go over 30 PSI, as the oil viscosity should ensure that it goes up to the relief valve cutout point, especially with HPR 30., regardless of how much clearance there is in bearings etc.

IMHO recheck that the pressure relief valve is not stuck partly open . This was pretty common in Saudi when I was there as the sand would get in and jam the valve.

I don't know whether I have mentioned before in the looong threads but also check for blocked pickup mesh, cracks in the pickup pipe, loose bolts on pickup flange , or leaking gasket on the pickup flange.
Regards Philip A

Originally Posted by clubagreenie

Which gauge are you reading off?

The one thing not mentioned is checking the sender unit (if it's an elec gauge). If it's the original smiths gauge then I'd look at the sender.

I have a mechanical oil pressure gauage (speeco) and have recently replaced the oil warning switch so there good.

Originally Posted by PhilipA

It seems really strange to me that it will idle on 20PSI cold then not go over 30 PSI, as the oil viscosity should ensure that it goes up to the relief valve cutout point, especially with HPR 30., regardless of how much clearance there is in bearings etc.

IMHO recheck that the pressure relief valve is not stuck partly open . This was pretty common in Saudi when I was there as the sand would get in and jam the valve.

I don't know whether I have mentioned before in the looong threads but also check for blocked pickup mesh, cracks in the pickup pipe, loose bolts on pickup flange , or leaking gasket on the pickup flange.
Regards Philip A

I had checked this when putting it together (second time, but I'll check it again) before pulling the timing cover off

Originally Posted by MacMan

It's a mucky, annoying job to do the timing cover gasket, but look at it this way. Drive the engine as it is and it will be toast. If you want to check any of the other clearances you'll be doing the gasket anyhow. You might be lucky and find it's the cause before you have to go further.

Depending on how vigorously you're prepared to be in chasing the cause before you change engines, taking the rocker covers off will allow you to observe how much oil is bleeding past the rockers as you drive the pump with a drill from where the dizzy would normally be. Same goes for the valley gasket if you're game to go that far - you'll be able to observe the cam bearings and have some view of the main and big end bleed rates.

yeah I don't want to be swapping motor, as this one has a 4.2 stroker in it when i bought it, & Im used to a bit more power. so I'd like to rectify the current motor. When the light first came on, it didn't make oil starving noise which seemed weird so I looked down the oil filler (in the rocker covers) and could see oil being pumped around the rocker shafts above cylinder one.

I like the drill with tappets off idea, will investigate further.....Luckily I've got 2 cars so not rushing this one