Hi guys, i just picked up a 99 th magna wagon from auction, it seems to have some oil supply issues, sometimes it runs fine, other times it starts knocking from the motor, and the oil light will flicker on, the oil is full, the problem comes and goes as it pleases. i know no history on the car. other than the knock when the oil light flickers on the car runs fine. the oil light and knock is only ever really present at idle, give it a rev and it goes away.

To me it seems like an oil supply/pressure issue, is there any known problems with a 3.5 litre motor i should be aware of?

My course of action at the moment will be to pull the sump off and check the pickup screen, change the oil and filter and bolt it back together to see how that goes. if it's still there i'll need to take it somewhere and get the actual oil pressure checked, but if anyone has any suggestions in the meantime let me know.

Thanks, Rick.

If the problem still persists after you've changed the oil and filter, and checked the pickup, have a good look at the pump. If there's excessive clearance between the gears, you'll get vastly reduced pressure.

When you have the sump off, check the bearing and clearances, if you have spun a bearing you will lose oil pressure. Check the pressure spring on the oil pump too.

all the above including bearings to check mains and conrod

replace the oil sender it may faulty

a flush before removing the pan

pump at a guess the pressure 50 - 80 kPa at idle

the sediment in the sump will be telling a story

do we have a internal oil pump..???

do we have a internal oil pump..???

Are you wondering if it sits inside the sump?

It's on the outside, sort of tucked under the crank pulley, and driven by the timing belt.

Before you go off removing sumps, removing main bearing caps and causing more of an issue, get a good engine flush like wynns or similar, give it a good run, drian the oil hot if you can (dont burn yourself) get some good oil, penrite hpr15 recommended, oil filter and give that a go.

I have seen in some times cars that have sat, the oil will not pump and this same problem. If you have a spun bearing you will know about it all the time, not just at idle. That is if the engine is still in fact running at all.

I had this once when I could not get penrite and used pensoil, used to be good, after a trip to mt gambier, had little oil pressure at idle, changed back to penrite all good again.