981 Boxter 3.4S Oil pressure

[ginettajoe]

Another question for this mine of useful information. What oil pressure should the engine run at when hot, both on tickover, and at 50/60mph? Thanks in advance.

[Rockster]

ginettajoe said:

Another question for this mine of useful information. What oil pressure should the engine run at when hot, both on tickover, and at 50/60mph? Thanks in advance.

Based on the Porsche info I have access to it does not provide a hot idle oil pressure. I can tell you from observing my 996 Turbo oil pressure gage at a hot idle the oil pressure is at or just under -- on a really hot day -- 2.0 bar.

Years ago my automotive mechanic buddies told me all the pressure necessary at hot idle is enough to keep the low oil pressure warning light from flashing on.

If I had to guess at a minimum hot oil pressure I'd probably say "1.0bar" or around 14psi.

Porsche gives an oil pressure at high engine speed. I can't recall this for my Boxster for my 996 Turbo "at n=5000 approx. 6.5 bar at 90C".

Your Cayman engine would probably be in the 5 to 6 bar pressure range at 5K or maybe more. (I seem to recall my Boxster's hot oil pressure call out is at some RPMs above 5K but that's about the extent of my (imperfect) recall.)

[bcr5784]

Rockster said:

Your Cayman engine would probably be in the 5 to 6 bar pressure range at 5K or maybe more. (I seem to recall my Boxster's hot oil pressure call out is at some RPMs above 5K but that's about the extent of my (imperfect) recall.)

I can't remember for definite, but I'd be very surprized if it was that high. It used to be commonplace to have pressures that high with mechanical pumps, but more recently, partly because it's unnnecessary, and partly for efficiency reasons (Caysters have an electric pump) lower pressures are generally used - in some cases as little as 3 bar, so I wouldn't get worried if it's nearer that level. I see on Planet 9 that 3 bar or even a bit less is about the mark - one guy quotes 48psi (3.2 bar approx) at 5k. See http://www.planet-9.com/981-chat/107483-oil-pressu...

Just been out in my 981S, didn't rev it very high - wasn't going very far and so not fully warm - but oil pressure 2.5 to 3 bar at medium revs dropping to 1.4 bar on tickover. The middle of the scale is around 2.7 bar, so I suspect that is pretty normal.

Edited by bcr5784 on Friday 17th February 08:25

Edited by bcr5784 on Friday 17th February 11:58

[Moog72]

Not sure exactly, but mine is around 2.3 - 2.5 under load and around 1.3 - 1.4 at idle

[Pope]

The MA1 series of engines has a demand controlled oil system - previously Porsche's had a peak regulated system (10 bar on some; 5 bar on most up to later cars) the peak pressure was controlled by a relief valve where anything over the peak pressure was returned to the inlet side of the pump or sump area.

Demand controlled enables lower pressures to be run which reduces overall fuel consumption due to lower loading on the oil pump.

Where an earlier car will produce 4.5+ bar at 4k rpm the later cars will be nearer 2.5 - 3 bar.

[ginettajoe]

That's great, thanks everyone, that is about the same reading as mine is showing, and I had wondered if it was lower than it should be!! That has reassured me, thanks again!!