Oil pressure warning CJCD

[tede12]

Hi all, got an 2013 A4 estate with what I think is the CJCD diesel engine. Not used daily just as a bus for the dogs and has just reached the dizzy heights of 216,000miles. Have noticed when the engine is hot particularly after a motorway run when I come to a stop I get a 'oil pressure engine low' warning which goes away after a few seconds. First happened about 3 months ago, did an oil and filter and seemed ok for a while (about 1500 miles ago, like I say not used much) but happening again recently.
Done a search online and found all sorts from oil pump + hex drive to lifters to PCV valves. I have use of VagCom and there is no DTC's relating to anything.

Not sure which of these faults apply to this engine so after some advice on where to start to be honest instead of playing parts darts.

All advice appreciated

[Crasher]

We would start with a direct oil pressure test, the gauge requires an M10x1 non taper adapter. With the engine up to temp (ideally 80 degrees C oil temp) at 2000rpm you need to see a minimum pressure of 2 Bar but ideally 3 Bar. If this isn’t achieved tbe
first step would be to drop the sump and fit a new oil pump; what is the VIN?

[tede12]

Thanks Crasher, I will try and get hold of a pressure gauge to check it. Is it possible it is not reaching pressure even when the low pressure light is

[Crasher]

Part of the VIN is no good to me and a cars VIN is not GDPR relevant data but if you prefer, PM it to me.

[Crasher]

It has the later balancer shaft and 10mm hex shaft n not known for causing trouble so a direct oil pressure test next.

[mickeybo]

Air on the side of caution on this 1.The oil pressure switch on your vehicle is a 1 wire connection. I would say you have either a faulty switch 0r wiring check wiring from switch body to battery neg

[tede12]

Mm scuppered my idea the hex shaft might be at fault, as you say I will need to get it pressure tested first as the pump could still be at fault even if the hex drive is ok.

So I did replace the oil pressure switch when I did an oil change as they were cheap enough with 03c919081, behind the manifold on the left hand side unless there is another one?

Don't suppose there is a wiring diagram anywhere for it as I didn't check the wiring really just replaced the switch

[Crasher]

I wouldn't say scuppered, more poured cold water on it; never assume anything, always check. Yes, just the one switch 03C 919 081

[tede12]

Right got hold of a pressure tester put it in place of the sensor and the news is not good...
Oil temp at 80degrees on VagCom
Idle- 0.6bar
2000rpm- 1.4bar

So looking like an oil pump 😞
I am guessing it has got worse after a recent regen as the oil smells a bit like diesel so must be thinned out a bit.
I have no idea what oil pumps are like to do on these is there a walk through anywhere?

I think the part number is 03L115105F from some online searching? All the usual suspects say out of stock (GSF, Euro etc) if that is the right part number there is BGA ones on ebay for around £100

[mickeybo]

check the first fall off point in any oil system all vehicles not to be over looked