Pentastar 3.6 oil pressure

[supton]

Seems high but maybe related to the VVT mechanism? Usually those are controlled somehow by oil pressure (if not controlled then actuated).

 

[cp3]

Some confusion here, it idles at 600 RPM (in neutral) and the minimum spec is 5 PSI. Minimum spec at 1200 RPM is 30 PSI, 3500 RPM is 62 PSI.

At warm idle I'm seeing 27-30 PSI. At 1200 RPM warm I'm seeing seeing about 35 PSI pretty regularly.

With the 8 speed, mine lives a lot of it's life between 1000 & 1600 RPM so while 1200 isn't far from idle is does spend a lot of time there.

 

[Hokiefyd]

My rental 300 was exactly like your Charger: it almost never rose above 2,000 rpm (unless I caned it) and hot idle was never below about 28 psi. I'm not sure why they maintain that type of oil pressure at idle. I realize minimum is lower, but it's significantly lower. The Northstar engines ran much closer to the minimum spec, even when new.

With the electronically-controlled oil pump, they should be able to account for wear-related increases in clearance and maintain the required oil pressure. If minimum spec is 5 psi, I don't see why they'd run closer to 30 psi, especially when they can control it with programming.

There must be a reason; I just don't know what it is. Maybe it does relate to camshaft phasing, as supton suggested above.

 

[cp3]

Noticed today that there seems to be a lower step on the pump as well. Cruising at around 70KPH it was turning 1200 RPM, pressure was about 35PSI (244KPA). As traffic slowed a bit and the RPMs dropped to 1000 I noticed the oil pressure jump to about 38PSI (260KPA). Looks larger in KPA which I see on the dash but still not what I would expect to see. It was consistently repeatable, I'll have to keep an eye on it and see if it is normal.

For sure not as dramatic as the jump @ 3000RPM.

 

[The_Eric]

Originally Posted By: cp3
Noticed today that there seems to be a lower step on the pump as well. Cruising at around 70KPH it was turning 1200 RPM, pressure was about 35PSI (244KPA). As traffic slowed a bit and the RPMs dropped to 1000 I noticed the oil pressure jump to about 38PSI (260KPA). Looks larger in KPA which I see on the dash but still not what I would expect to see. It was consistently repeatable, I'll have to keep an eye on it and see if it is normal.

For sure not as dramatic as the jump @ 3000RPM.


The PCM is accounting for the extra low speed load.

The first time I ran into this in a John Deere 8430T with a 9.0L engine. Going through the field the oil pressure seemed low- around 27-30psi, since I was used to typical diesel engine oil pressures of 50-60psi. Made a call to my friend who had worked at the Deere dealer, he told me that the pump is electronically controlled and the PCM will dial up pressure for various conditions and lower it when it's not required. Knowing this, I was able to fiddle around a bit and induce/repeat it.

 

[cp3]

Ya this makes sense but if you see the quote posted earlier in this thread about the variable pump, it only mentions the step at higher RPM. The second, lower step brings the higher than average idle pressure into perspective but still doesn't explain the reason behind it.