Oil pressure warning & need advice.

[NikoG93]

Hey everyone.
Got myself a project to work on for quite a cheap price.
A 2005 GTI fitted with AXX 2.0 engine, car was standing for 7 years.
When running if revved now and again comes up with Oil pressure warning please stop engine.
Cleaned it all up, changed oil & filter, checked wiring to pressure sensor, getting 12v no probs, changed pressure switch while i was down there.
Took sump off, cleaned pickup pipe which wasnt that really dirty and checked oil pump +
Balance shaft assembly, no play in balance shafts and oil pump looks like brand new if looking from the side where pick up pipe goes.

Checked oil pressure with 2 different gauges and im getting 4 bar on cold
Idle and increasing up to 5 bar if revved, only gone up to 4k at most, didnt want to rev past it.
On hot engine if i start it up the oil pressure sits just above 2 bar, and increases up to 5 bar if i rev it up to 3k-4k rpm.

Engine itself sounds ok, looking inside oil cap when engine is running, theres definitely oil at the top of the engine too, so i really dont think theres an actual oil pressure issue.
Is there anymore wiring i can check? Maybe someone has a diagram for oil pressure switch wiring, maybe theres a wire broken that goes to the cluster thats broken?

Any advice, ideas or wiring diagrams are highly appreciated.
Im a diesel man and work on diesels daily, no stranger to petrols but not so good with them especially with vag petrols, know absolutely nothing about them.

Thanks.

Nick.
 

[MKVASMR]

Don’t like shouting out bad news but you’ve said that it’s been sitting. Maybe rod bearings? I would try dumping a few cans of engine flush additives. Make sure there isn’t a double oring on the oil filter housing.

[NikoG93]

Don’t like shouting out bad news but you’ve said that it’s been sitting. Maybe rod bearings? I would try dumping a few cans of engine flush additives. Make sure there isn’t a double oring on the oil filter housing.

How would rod bearings be affected from vehicle sitting? Never heard of this to happen, but would like to know more on this subject.
Also, ive done oil filter myself and pulled original oring out, so definitely not that too.
Gonna try an engine flush tomorrow amd maybe get some other additives.
Still trying to source a wiring diagram to see if it could be an electrical issue. Again,it sounds okay except for auxillary end on which everything is rotten.