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[tomuxzz]

Hi,
I have situation when Engine is hot. After driving some time. I think Engingine RPM drops too low (About 500) when it gets to 500 sometimes I got oil presure lamp. If I turn on AC for example. Engine RPM Jumps to 590rpm +- and Oil presure lamp turns off I added video. (in that video I accelerate a litle bit, after some time I realesed accelerator).
Maybe someone could advise me were to start check search problem ? look for a vacuum leak Or should I take on a more serious project and try to restore my old oil pump from another engine and replace it?

For now I dont have check engine error.
I changed origanal Cadilac Oil sensor to calibra oil presure sensor, because its impossible to find Cadilac senor.
I changed oil to 5w40
And I'm thinking maybe try to change spark plugs.

https://www.youtube.com/watch?app=desktop&si=-KBjnXvj_qddbOfF&v=baX2EZN64IE&feature=youtu.be&cbrd=1&ab_channel=Tomas

[Andy B]

how many miles/kilometres are on the car? Low oil pressure at idle can be due to worn main & big end bearings ... 

[STEMO]

It shouldn't be idling at 500rpm, though.

[tomuxzz]

how many miles/kilometres are on the car? Low oil pressure at idle can be due to worn main & big end bearings ... 

139 000km

[tomuxzz]

It shouldn't be idling at 500rpm, though.

I think same, and I dont know where to start look problem

[tomuxzz]

And oil presure is always minimum on lowest white bar.

[tomuxzz]

how many miles/kilometres are on the car? Low oil pressure at idle can be due to worn main & big end bearings ... 

but I have this problem only on hot engine, and after driving some time.

[Doctor Gollum]

It might be covered in the owners manual.

Basically it can be considered normal, especially on an older engine with some hours/miles on it.

However oil gets thinner as it gets hotter, so if your oil pressure is low when the engine is fully warmed up, then there's a chance you're using the wrong oil.

Equally, if the oil pressure doesn't increase with rpm then you need to prioritise removing the sump and checking the pick up. If it's blocked, you've found the problem, but if it isn't then the pump itself could be failing.

The idle speed is non adjustable on the 3.2/2.6/2.2 but 550rpm rings a bell as being normal.

[tomuxzz]

It might be covered in the owners manual.

Basically it can be considered normal, especially on an older engine with some hours/miles on it.

However oil gets thinner as it gets hotter, so if your oil pressure is low when the engine is fully warmed up, then there's a chance you're using the wrong oil.

Equally, if the oil pressure doesn't increase with rpm then you need to prioritise removing the sump and checking the pick up. If it's blocked, you've found the problem, but if it isn't then the pump itself could be failing.

The idle speed is non adjustable on the 3.2/2.6/2.2 but 550rpm rings a bell as being normal.

Oil presure increases with rpm, for me looks like normal.

[Doctor Gollum]

If you're using 5W30 switch to 10w40 and see if the hot idle pressure increases 

[tomuxzz]

If you're using 5W30 switch to 10w40 and see if the hot idle pressure increases 

I tried this weekend, increased a little bit, but its still little bit missing when engine is hot. Now its enough just to turn on AC to reach minimim stock oil pressure norm on iddle. (when rpm is 550-600 its ok) but when 500 sometimes I get that damn lamp
I'm thinking to remove sump now..

[Kevin Wood]

Might also be worth checking the oil pressure relief valve while you're at it, although I can't remember where they are on this engine.

Blocked oil pickup is definitely a possibility and worth eliminating.

Could just be a lazy oil pressure switch?

If the oil pressure picks up quickly at higher revs it's possibly not work worrying about if the above check out OK.

It's normal for some variants of the V6 to idle as low as 450-500 RPM from memory.

[Nick W]

I wouldn't be making any drastic decisions without actually measuring the pressure.

[cam.in.head]

and as regards the idle speed its controlled via the air valveon the side of the plenum. if you squeeze the rubber hose from it the ecu should try to compensate by opening the valve more which will be obvious when you let go of the hose . if this isnt happening its likely the valve needs cleaning (or replacing).

[Doctor Gollum]

and as regards the idle speed its controlled via the air valveon the side of the plenum. if you squeeze the rubber hose from it the ecu should try to compensate by opening the valve more which will be obvious when you let go of the hose . if this isnt happening its likely the valve needs cleaning (or replacing).

If it's a post 2000 Catera it is DBW... Basically a 3.0 block running 3.2.management