View Full Version : 2012 Audi A4 TDI Oil pressue light **Please help**
chief_67
26-02-2025, 10:24 AM
Hi,
I need some advice please. I've had my A4 black edition 2.0 TDI for a few months now and I was getting the oil pressure light on the dashboard. Took it to garage, they did a service and and confirmed with me the oil was dirty as well as the oil filter, so they did the full service.
They also checked the oil pressure after the service by using the tool they had and confirmed the oil pressure was fine.
Now just over a month later the oil pressure light had come back on this morning.
Since the service everything has been fine, no knocking noises, oil level has been fine.
Does anyone have any idea what it could be, maybe change the oil pressure sensor as it could be faulty, as that was not changed at the time of service.
I've read about the HEX key in the oil pump to be changed, but when the garage check the oil pressure after the service they said it was fine.
Off the top of my head I think they said they unplugged the sensor, then plugged their device into the plug and read the oil pressure that way. It must have been a big job as they had to charge me to check the oil pressure because they had to strip it down, whatever that means.
TIA
Crasher
26-02-2025, 02:58 PM
It could be the new oil has released sludge in the engine which is now blocking the pickup gauze. That is sump off which is a pain on an A4.
chief_67
26-02-2025, 03:20 PM
It could be the new oil has released sludge in the engine which is now blocking the pickup gauze. That is sump off which is a pain on an A4.
When I got it serviced in first week of January the garage did an oil pressure check after the service using their equipment and the pressure was fine. If it was released sludge I presume the oil pressure will give a low reading. Do you think it still could be released sludge.
I was leaning towards changing the oil pressure sensor. I've read that the Audi petrol are known for the pickup pipe blocking but not the diesal's.
Crasher
01-03-2025, 12:12 PM
I have seen bad Diesel sludge, it is how we acquired or loan car Passat.
chief_67
21-03-2025, 09:39 AM
An update on this, spoke to my mechanic who is a VAG specialist who told me could be oil pressure sensor faulty, so bought a new one from Audi and will get that changed next week.
I did ask him about the pickup gauze could be blocked, he said doubt it will be that because when we did a oil pressure test the readings were fine.
Since it came on first on the 26th feb up until now it's only been on twice, and no issues with engine.
chief_67
29-03-2025, 10:59 AM
Need some advice please. So got the oil pressure switch changed and still bringing the light up. The VAG tech told me to check the wiring next so need to go to an electrician.
I did say do you think it worth checking the pick up gauze is not blocked, he saying it can't be that as when did the oil change 500 miles ago we did a oil pressure check and the readings were fine.
Need some advice of what next step to take. The car drives fine no issues even when the light comes on.
Crasher
29-03-2025, 11:22 AM
You need to get the pressure checked again to be 100% sure it is a false alarm. What is the VIN and mileage?
chief_67
04-04-2025, 10:06 AM
Update is that I've ordered a pick up pipe from Audi and will fit a new HEX key at the same time.
Spoke to KMB parts direct about wanting to buy the hex key and he is advising me to change the oil pump and balance shafter as just changing the Hex key will end up bringing the oil pressure light back. He saying if the Hex is worn so will the inside of the oil pump.
I don't know if he giving me good advice or trying to sell me the oil pump and balance shafter.
Their website: Oil Pumps from KMB Parts Direct specialist Oil pump replacement parts, Audi 2.0tdi, VW 2.0tdi, engines, support, help, advice, Sheffield, UK, England. (https://www.kmbpartsdirect.co.uk/shop/oil_pumps.html)
What you guys think.
chief_67
05-04-2025, 10:16 AM
You need to get the pressure checked again to be 100% sure it is a false alarm. What is the VIN and mileage?
Mileage is about 105,000. It's a 2012 A4 2.0 TDI 143bhp CJCA engine code.
Crasher
05-04-2025, 01:52 PM
CJCA started for 2013 model year. You need to strip it down to check the hex key wear but at that mileage it isn’t common for the 100mm key to be a problem
https://hosting.photobucket.com/4493c99d-e8cc-46f0-b7b5-7857cc7d4998/609c8405-474c-444f-969f-2bb4a8c3ea00.jpg?width=590&height=590&fit=bounds
chief_67
07-04-2025, 10:14 AM
CJCA started for 2013 model year. You need to strip it down to check the hex key wear but at that mileage it isn’t common for the 100mm key to be a problem
https://hosting.photobucket.com/4493c99d-e8cc-46f0-b7b5-7857cc7d4998/609c8405-474c-444f-969f-2bb4a8c3ea00.jpg?width=590&height=590&fit=bounds
Going by the logbook Sept 2012 date of manufacturer and CJCA engine code.
Thanks
Crasher
07-04-2025, 01:30 PM
The next model year usually start in September or earlier, March sometimes.
chief_67
08-04-2025, 06:39 PM
CJCA started for 2013 model year. You need to strip it down to check the hex key wear but at that mileage it isn’t common for the 100mm key to be a problem
https://hosting.photobucket.com/4493c99d-e8cc-46f0-b7b5-7857cc7d4998/609c8405-474c-444f-969f-2bb4a8c3ea00.jpg?width=590&height=590&fit=bounds
It's a Sept 2012 model and CJCA engine code going by the logbook.
chief_67
10-04-2025, 07:02 PM
So got the hex key changed and new pick up pipe fitted.
This was the state of the parts that came off. What you guys think. There was some wear on the hex key and the pickup filter did look slightly clogged up.396633966439665
Crasher
10-04-2025, 07:28 PM
Nothing wrong with that key
chief_67
11-04-2025, 10:30 AM
Nothing wrong with that key
How about the pick up pipe does that look ok.
Hope it sorts the issue out.
So far firstly did a full service which helped, as before it came on every journey, since the service it came on about a month later and that was once a week.
Change the oil pressure sensor (from Audi).
And now changed the pick up pipe and hex key (from Audi).
Mechanic says if it comes on again will have to go to electrician as it could be wiring.
The car has been running fine throughout, no issues with the engine. One thing I've noticed the pressure light would only come in when the temp is sitting at 90 degrees for a while (30+ min) and that usually when I'm in slow or standstill traffic.
Any ideas what else it could be in case it comes on again.
chief_67
22-04-2025, 07:07 PM
So the Oil pressure warning came back. I'm stumped what to do next any thoughts.
The car drives fine with no issues.
Crasher
23-04-2025, 09:16 AM
You need to view the pressure with an external gauge, the fitting is M10x1.
chief_67
23-04-2025, 11:31 AM
You need to view the pressure with an external gauge, the fitting is M10x1.
Already did that and the reading was fine.
Crasher
23-04-2025, 01:42 PM
What is the VIN?
chief_67
23-04-2025, 08:02 PM
what is the vin?
wauzzz8k2da064612
chief_67
25-04-2025, 08:26 AM
wauzzz8k2da064612
Any advice for me Crasher.
Crasher
27-04-2025, 05:26 PM
I had a good think about it over lunch and I came to the conclusion that IF it has perfect oil pressure then it must be a dash fault.
chief_67
29-04-2025, 09:34 AM
I had a good think about it over lunch and I came to the conclusion that IF it has perfect oil pressure then it must be a dash fault.
Crasher the oil pressure check was done end of January after a full service and the reading was fine. Is it worth getting another to double check all is good.
What should the readings be either the engine being cold or warm. Is it best checking the reading when the engine is warm. TIA
Crasher
03-05-2025, 01:59 PM
I can’t look the spec up at home but I think it will be the usual absolute minimum 2 Bar at 2000 rpm and the engine at running temperature BUT I am not happy unless I see 3 Bar, hopefully increasing to 4 Bar or more with some revs.
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