# Oil pressure warning light.



## bigscout79 (Aug 24, 2004)

2004 a6 2.7t quattro. ~60k miles.
Feel free to Skip to bold if you don't feel like reading all of this.
I am about 8k into a 10k oil change interval. I am driving home from work on Friday, and the red oil can with no other words (sensor/min) shows up and beeps. Freaks me out so I pull over shut it off and dig out manual. I read that it's bad - low oil pressure. I check the oil, it's low but not really low. I start it up and the warning is gone? I drove home slowly, parked it, added about .5 quart of oil to bring it up to full and started it again - no warning light.
I started it up on monday and pulled out about half way down the block (whenever the revs got over 2k) the light comes on. Park it and take the wife's Touareg. I got the vag com on it last night and couldnn't get it to throw the oil pressure warning - it was "OK" and I drove it around the block etc. Great - fixed itself, my kind of car.
Wednesday morning - today - I go out start it up and let it warm up for 5 minutes even though its like 40 today. I get about 7 miles into my trip when it goes off again - it doesn't stay on though, it comes and goes. Basically just enough to really make me nervous but then calm thinking it's a sensor, then nervous waiting for the engine to seize.
*Ideas? Is it safe to drive 30 minutes to the dealer? If I get a manual oil pressure tester gauge, where is the test port on the 2.7? Just do an oil change? Just install a new sensor? I've read conflicting reports - is there 1 or 2 sensors on this one?* 
Thanks in advance. 
Here's the log - what I think to be errors are at the end.
http://public.blu.livefilestor...nload 

_Modified by bigscout79 at 8:46 AM 3-10-2010_


_Modified by bigscout79 at 8:47 AM 3-10-2010_


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## bigscout79 (Aug 24, 2004)

I'm going to pick up a new sender and change it out with an oil change.
Beyond that any suggestions are appreciated.


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## temagnus2004 (Mar 19, 2008)

*Re: (bigscout79)*

I would drop the oil pan. Its quite possible that something may be clogging the suction screen on the oil pickup.


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## bigscout79 (Aug 24, 2004)

*Re: (temagnus2004)*

Haven't ever done this on the a6, is the gasket reusable? Any thing else I might need to know? Any suspension bits need to come out first?
I'll take a look for writeups.
Thanks.


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## julex (Jan 24, 2009)

*Re: (bigscout79)*

No write up but deffo don't drive it like that. On normal car low oil pressure is not an instant engine killer but on 2.7t it will kill the turbos pretty quick. If you absolutely have to drive it for some reason, make sure you drive like 200000 year old grandma, absolutely no boosting.
The oil pan doesn't require any fancy gaskets, just an appropriate oil resistant silicone gasket maker will do. If the oil pump pickup screen is clear, you might have clogged oil filter with faulty bypass or oil pump failure.
Are you using OEM oil filters or some cheapos which are known to cause issues once they clog since some lack bypasses?


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## bigscout79 (Aug 24, 2004)

mann filters. 
I'm going to change out the sender and get a manual gauge on it this weekend. That and an oil change and we'll see - short of that working, I'm going to pay to have flatbedded down to my shop.
Thanks all.


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## GLS-S4 (Jun 6, 2005)

*Re: (bigscout79)*

Wise to replace oil pressure sensor first.
If dropping pan, strongly recommend Audi pan sealant as it will last the longest. Surfaces must be oil free, clean and dry for best seal. Be sure not to use excess sealant as it will get inside pan and collect on oil pickup tube screen causing partial restriction.
Just out of curiosity, what kind of oil are you using that only needs 10K change intervals?


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## bigscout79 (Aug 24, 2004)

Edit: wix filter
I thought I was following the manual with the 10k oil changes - last time it was elf - this time I found some 502 spec valvoline 5w30 synth (i think it was 5w30)at walmart since I didnt' want to wait for the shipping.


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## bigscout79 (Aug 24, 2004)

*Re: (bigscout79)*

UPDATE:
Oil change/sensor change seems to have fixed it. I ran it for 20+ minutes up and down the road watching the vagcom and 99% of the time it was ok - sensor reading ok. No warning light, got oil up to temperature, probably went about 15 miles mixed in town/highway. Everyonce in awhile looking back through the log it was reading low pressure, but it was only at idle and then only when it dropped below 700ish RPM. Any chance this is normal and the car knows not to fault on these errors? It wont' read them in park, but it will in drive idling and its only sometimes when the rpm drops down.
Mostly - I'm glad there's no light and I don't have bad problems. 
High points: 
-easiest to get to it while oil filter is out.
-Sensor on the 2.7 is right above oil filter housing it screws in towards the front of the car (plug faces back of the car when installed). 
-24mm deep socket for the sensor
-had to drop sway bar (left ends attached)
-had to pull the rubber intercooler(I think that's what it is) hose and steel one (not fun). 
-Steel section screws into sump with 2 #5 allens.
Thanks for your help guys.


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