My mechanic checked and see nothing wrong on the ground also, he did cleaned up everything, manual pressure check okay.

He did change oil filter and used Audi Synthetic oil, now I have been driving car for over a week with out any warning. Hope it will keep low and never appear again.

Don't know whether clean worked or oil change. This might help others to debug having same issue.

Thanks to Bob especially.

 

if your using conventional oil it might when i had a problem with my oil pressure it was got alot worse when i had to get regular oil from the gas station and if after 100 thousand miles you switch to high millage conventional oil not relizing that its thick(to try to keep seals) and not like full synthetic or as good, my oil pressure sensor turned out to be the previous car owners mechanic leaving the little bottom bolt that you cant see on the oil pressure sesor way in the back thats a pain to get to but completely tech. fault not an audi thing

 

the oil. one of audis greatest drawbacks the dreaded 8 doller a quart oil and big expensive oil filter and you still gotta change it every 3,000 or that stuff is like syrup and even valvoline instant oil change kid can tell ya nothing but full synthetic ever no matter the millage and no thick oil additive stuff like motor honey garbage auto-zone has the three specific brands and weights to use 0w40 mobile one adv synt with filter(can get 5,000 with these to just gotta add a little) castrols 5w30 full syn and i forgot the other one used these two castrols cheaper and about the same

 

was your oil pressure solved by using correct sync oil??

or

it is because previous owners mechanic didn't fit the sensor correctly??

 

low oil pressure warning is back after 2weeks of driving.. only in city driving and when car is all heated up Coolant temp in middle and engine oil temp just 2readings (normal).

no clue what to do next??

 

You say you get the warning when driving around the city. Do you get it while idling? when the RPMS are below a certain number? when accelerating? when stopping? that is, is there any pattern to when you get the warning?

Have you had a mechanical gauge hooked up while driving in the city and when you get the warning light (so that you can verify that you have good pressure when you get the light - doon't tell me that the mechanic just checked it with a mechanical gauge while the car was on the rack!!! That ain't a real test!)?

It's starting to sound like a bad bypass spring in the oil pump relief valve.

Another test - take a 1000 ohm resistor and put that between the oil pressure sensor and ground and drive the car and see if the light shows back up. If it does, it is in the cluster (or ECU if that is involved - I'll have to hook up the old VAG-COM cable and see if it displays oil pressure). If it doesn't, see my previous paragraph.

Let us know the results,

Bob

 

Only pattern I observed is when RPM between 1000 and 2000 with speed around 40MPH.

Yes i did put the mechanical pressure gauge and drive around and pressure was good all the time (I can't get pressure warning in this case as the sensor is removed).

Was wondering if Ross Tech vag com will be helpful to keep monitoring the pressure??

In case of Instrument or ECU what are the options I have?? do you suggest to throw a new oil pump and see??

 

Sivak,

I plugged in my Vag-Com and looked at different measuring blocks and all I could find was block 001 under Instruments, which showed that the oil pressure was OK. No reading, just OK.

To me, this implies that the oil pressure sending unit is an on/off type of unit which switches to ground when low oil pressure is experienced.

Cheap fix - disconnect the wire from the oil pressure sending unit. If the unit is a open under low pressure type, you would have to tie the wire to ground t make the icon go away.

Slightly more costly fix - do above and install mechanical pressure gauge. This will give you the piece of mind that you can keep an eye on your oil pressure just in case you have a problem in the future.

Next more expensive fix - replace the gauge cluster and see if that fixes the issue.

I vote for the second option so you can verify that you do not, in fact, have a low oil pressure issue. I would NOT throw a new oil pump at it until I have spent a couple of weeks with the mechanical gauge in place and have verified a low oil pressure issue.

Good luck,

Bob

 

Did you try seafoam yet?

 

Bob, I would try these steps and this is what makes me convencing.

Yesterday went on 30miles drive without any issues and outside temp was below 70. Now it made me thinking that eveytime I had this warning outside temps are high. By the way I also have issue with instrument cluster LCD, some lines die if temps are ups. Cluster might be the culprit, so I researched for a used cluster.

Found one on similar vehicle with with little higher mileage, mine is 111K it has 118K now I could live with it :-)

I know few years back it is impossible to correct mileage, is it possible now with any tool?? I am plugging and monitoring readings with Ross tech cable and laptop :-)