Rebuild at 78k km?

[andyroxs]

Made a thread on this issue a while ago but things seemed to have taken a turn. Got the low oil pressure light on my 2012 A4 a couple weeks ago and had it towed to the mechanic. He replaced the oil control valve and the light went away. Two days later it came back. Now he's further replaced the oil pump and pressure still drops to 0psi (starts out high 20s then drops to 0). Now we're out of ideas and thinking of a rebuild... Seems unusual for a car with such low KM? Car has always been maintained on schedule. Any ideas would be appreciated.


Sent from my iPhone using Tapatalk

[B44]

You want to talk to audi of america about the issue they might help

[andyroxs]

I would but my car is Revo tuned. mechanic will be replacing balance shaft tomorrow. hopefully that does it


Sent from my iPhone using Tapatalk

[B44]

Does not matter of the tune. You should know the dealership that is cool with tune. I had my stage 2 piston job done for free at 108k with the tune. Aoa paid for it. Anyways good luck

[andyroxs]

stage 2 piston is for oil
consumption and there is an extended warranty on that though. I'm out of warranty... thanks for suggestion though!


Sent from my iPhone using Tapatalk

[andyroxs]

mechanic thinks it's part of the balance shaft


Sent from my iPhone using Tapatalk

[Allowencer]

Does your mechanic believe oil volume is being lost at the balance shaft's bearing and that is what is causing your low oil pressure symptom?

[zokissima]

Who's your mechanic? I'll be in the Markham area shortly myself, need a good one :)

[andyroxs]

no, we literally have no idea... here are the specifics...

-Car has 77k and just got a Revo tune last month
-Drives 100% fine, but when idling for long periods of time, pressure creeps down to 0 psi, as assessed by an analog gauge
-No filings in oil pan, no sludge, pickup screen is clean, etc
-Replaced oil control valve and oil pump
-Did an oil and filter change
-Car doesnt really burn oil, maybe 1L every 5k which seems common/normal in these cars.

He is still in the process of checking the balance shaft (as pictured above), he has heard that this has been the problem in a few rare cases on these engines. If that turns out the be not the problem, the engine will be getting rebuilt.

I would assume I would hear knocking or vibrations if the bearings are worn but none of that....

I did hear some people say the PCV was the cause of their oil pressure but that doesnt make much sense to me.. maybe ill try it as a last ditch attempt. Thanks for the responses guys, any other suggestions would be appreciated!

[andyroxs]

PM'd.

Any possibility of this being an electrical gremlin? Checked all the wiring and they visually appear to be fine, but am at a total loss for how this can happen mechanically without any knocking.. Dont want to tear the engine down only to find that nothing was wrong with it.

[NLPed68]

Try a mechanical guage to verify the actual pressure?

[andyroxs]

Try a mechanical guage to verify the actual pressure?

Yep, have been having one. Pressure drops to 0psi at warm idle


Sent from my iPhone using Tapatalk

[Allowencer]

Where do you have the mechanical gauge installed at?

[andyroxs]

my understanding is that there is only one mounting point for this generation of engine, near the oil cap?

[Allowencer]

you pulled out the stock sensor then?

[andyroxs]

yes, is there anywhere else I can check pressure?


Sent from my iPhone using Tapatalk

[Allowencer]

Has this been checked / verified: Oil Pressure Regulation Valve (N428)

[andyroxs]

unfortunately that was the first thing we replaced and no dice :/ hopefully the balance shaft is found to be the culprit


Sent from my iPhone using Tapatalk

[Allowencer]

Here are the other areas I'd check too:
- Valve uni to the oil filter
- Oil cooler
- Both pressure switches around the oil filter:
* Oil Pressure Switch (F22)
* Reduced Oil Pressure Switch (F378)

[Allowencer]

F378 is the one to remove to verify oil pressure mechanically. Here are the oil pressure's you should be seeing:

¤ Oil pressure when the vehicle is idling: 1.2 to 2.0 bar (17.4 to 29 psi)
¤ Oil pressure at 2000 RPM: 1.6 to 2.2 bar (23.2 to 32 psi)
¤ Oil pressure at 3,700 RPM: 3 to 4 bar (43 to 58 psi)

[andyroxs]

thanks for all the help! will report back


Sent from my iPhone using Tapatalk

[Allowencer]

Anytime. I know motors quite well, I dont know this one internally in and out very well, but in general, if you lose oil pressure as the engine heats up that means the oil loses viscosity (which is normal) and the tolerances (some where) are not being fulfilled anymore. Usually when you spin a main bearing, this is a tell tale sign. Since you mentioned you guys didn't find any babbit material, you should be ok in that regard.

I just don't see how a balance shaft could cause this unless the balance shaft feed/ bearing is toast. This also depends on where that feed is within the oil circuit.