deherrera21

i just purchased and 05 audi a4 i took it in for and oil change and as i began to drive away the oil pressure indicator started flashing they had the car in the shop for 3 days and could not find the problem. they tried saying the oil pan was replaced and an excessive amount of gasket was applied. the problem was some what resolved when they added 20/50 motor oil. has anybody herd of this or have any idea what can be done.

mayhem100

Their explanation doesn't amke alot of sense to me. Nor does their fix. If the pan was replaced and too much gasket material was applied then why would changing to a thicker oil help? Sorry, but I don't see how those two are related...I think they're guessing and just tried thicker oil and when the light shut off they sent you out the door as quickly as possible.

Just fixed this on my wife's 3.0. Hopefully your issue is similar.

On my car, the oil pressure sensor's wiring harness was pulled really, really tight from the sensor. Tight enough that it was causing connection problems when cornering. I opted to do a seafoam treatment in the crankcase to help breakup any crud that might be lodged in the system, particularly the pickup tube. Then I drained the pan while the oil was searingly hot (and most free flowing), pulled off the pressure and level sensors and did a physical inspection inside the pan to look for debris or signs of sludge. Reassembled everything and refilled with 7 quarts of Mobil1 0w-40. I've had no issues since then, about 500 or so miles at this point...the light was flickering on with every medium lenght trip...say hops longer than about 15 miles or so.

The 20-50 oil you put in there is probably not good and I doubt its on Audi's list of recommended oils. I would do another change and put in the right synthetic oil.

Alot of guys seem to get the low oil pressure light, from what I cna tell the majority of them are 1.8T cars that have gotten a sludge buildup in the motor and the key factor that seems to cause low oil pressure is when some of that sludge gets lodged into the oil pickup tube inside the pan. Only way to fix that is to pull hte pan off and clean it, unfortunately this is a big job on the 1.8 as the pan straddles the front subframe...on the 3.0 it looks like a pretty easy job as the pan is way out in front.

If you're still under the used car warranty period I would take it back to the shop and talk to the service manager or consider trying to return the car. I wouldn't trust the thing myself. You might be able to get the service manager to agree to allow a dealer to inspect and possibly repair the car. The dealer would have the most expert mechanics and access to the car's service history.

a44me2

The 20 w50 oil is an old shady car guy trick to cover up leaky valve guides, worn oil rings on pistons and unfortunately, to boost weak oil pressure. Sounds like they know there is a problem and did what it took to get you to leave. I would guess a sludge problem too unless you have noticed blue smoke from the tailpipe before this oil change. If you have no blue smoke then you must try to deal with your potential sludge problem. I would change to oil to the proper grade first, either 5w40 or 0w40 and see if the oil pressure light comes on again. If it does not then dirve the car and change the oil and filter early (around 1000 kms). Seems like a waste but if you have a lot of sludge being too agressive at removing it can be fatal to your engine by clogging oil passages with the dislodged sludge. If it does come on then run an engine flush and change the oil and filter immediately. I would also drop the oil pan and make sure there is no sludge in the pan and that the oil pickup is not clogged and installed correctly. Your pan sounds like it has been off recently and maybe your oil pickup is not properly seated or even damaged. If the pressure light goes off then drive it for 1000kms and change the oil again.

deherrera21

the thing i forgot to metion was this was all done at an audi dealership. that was their first thought and they where going to clean all the sluge from the oil pan and they removed the pickup tube cleaned it and still the same problem. they guessed that it could have been run with out oil. if this is the case would it be posible to bore out the cylenders and replace the pistons ect. . . but i will try flushing in myself and putting 10w 30 in it

mayhem100

How long have you had the car? Your fiorst post amkes it sound like you might be under a warratny ot grace period, but I don't know.

If possible I would try to make the seller fix the issue or return the car asap. You don't want anything to do with owning a car whose engine has been run for any period of time without oil. That is a dead engine waiting to happen.