MK4 2.0 Oil Pressure Low?

[axeman74]

Hi all,

The patient is my 2004 MK4 Golf 2.0 APK engine with 137k's.

I have been getting an intermittent "STOP- Low Oil Pressure" warning. It usually goes away before I even get a chance to pull off the road.

I know the oil pressure switch on these can be problematic so that was my first suspicion. But just in case I hooked up my trusty old Ryco oil pressure gauge and got the following readings;

- Approx 50psi on start up
- Drop to approx 20psi once warmed up
- Occasionally drops as low as 10psi after long period of idle
- Rises back up over 50psi when revved over 200rpm

Before anyone menions it, the engine has maximum oil level (5w-30), pulls nicely, no out of the ordinary noises and is otherwise running great.

I can't seem to find the factory min oil pressure specs for this engine. Anyone have these? And anyone think I am actually dealing with a low oil pressure issue here rather than just a faulty switch? Opinions welcome.

Thanks

Axeman74