Oil Light Flashing- questions

[A4pilot]

Oil Light flashing- checked oil quantity and it is full- what are the other possibilities for having this light flashing? Thanks

[salz2135]

two possibilities come to mind right away:

1) you have an oil sludge problem, so despite having proper oil levels, the motor doesn't maintain pressure while running

2) the oil pressure sending unit could be malfunctioning.

[A4pilot]

could it be a bad oil pump?

[salz2135]

how many miles on the car? do you use synthetic motor oil?

[RippleChip]

Yes it could be a dead pump.

If the pump is good, look for sludge and buildup in the lines and on the filter

[nizmosx]

there is many things it can be. everything mentioned above could be a possibility. i sugest you do not start it up anymore and have someone check it out immediately. If you can do the work then do it. Do not start the car until you have an oil pressure gauge and or the audi scan tool. It would be a good idea to change the oil sending unit, since its only 12 bucks and pretty easy to replace. It would be best to have the sending unit changed and have an oil pressure gauge hooked up because you can cause further damage to the motor if it is running and not producing healthy oil pressure.

This happend to me twice, first time was sludge, and the second time was a failed oil pump and one bad rod bearing. if i would have driven on the ccar, it would have caused more damage.

[Rosati]

Listen very carefully to wat has been said.

On a more serious note, if you hear your valves start to clack and get loud, the its either sludge buildup or a bad pump. Both are very serious and can ruin an engine.

So loud valves are your first and maybe only sign of your 1.8t about to blow so listen carefully until it is fixed

[A4pilot]

OK, more info- at idle, there is no oil light at all....when in nuetral/in gear above 2K RPM's oil light comes on. Any ideas whether it is sludge or maybe something else?

[A4pilot]

SO should I seafoam and try to get rid of the sludge>

[bass_lover1]

Seafoam would work if you didn't already have signs of sludge. Since your low oil pressure light has come on, seafoam takes about 300-500 miles of driving to really work, and you don't even want to crank the motor over right now.

Check the oil pressure if you can, but your best bet is probably to drop the oil pan, and change the pump, then with a fresh pump you might be ok to do seafoam or even the diesel flush, as you don't run the motor for that one. I'm sure someone with more knowledge on this can help shed some light for you.

[Euro-Tuner]

I'd keep an eye on the pressure gauge...

[onemoremile]

SO should I seafoam and try to get rid of the sludge>

You might as well try adding a can or two of Seafoam to the oil and letting it idle for a half hour or so. Change the filter and put some cheap oil in there and drive around gently for a while before changing the filter again and putting good synthetic in there. During that first oil change I'd wait until after the Seafoamed oil drained out and run a quart of cheap thick oil through with the plug still out. This may push a blob or two out.

There is no guarantee that this will help but it should. You may have a bad oil pressure sensor or a bad oil pump that can't meet demand above 2k rpm. Then again, it may just be a sludgy clot that restricts flow above 2k rpm and causes the flashing light. The Seafoam may just be the Drano you need.

[johnjonfenomeno]

I had this problem... Turned out to be the oil sender. The way you can tell if its an oil sender is by taking it out and shaking it. The units seem to be a ball/spring type of unit.. sort of like a hallman manual boost control. If it makes a rattling sound... that means its defective... its unable to determine pressure because the ball/spring unit is out of wack.. Could have deteriorated from the heat or pressure or a combo of both.. I compared this to a new sending unit and i shook it... It remianed solid and no play at all meaning the ball/spring unit is in tact and therefore able to correctly determine pressure....

Just useful FYI .. for those in order to troubleshoot stuff before proceeding any further.

[Kyle H]

I just had my flashing oil light come on today while in traffic. Just changed my oil wednesday, 6,000 miles on a new engine with the new pump, didn't replace the sending unit.


I'm assuming it's the sending unit, I'll be getting an oil pressure gauge ASAP though.

[walky_talky20]

For the oil pressure warning light the FIRST step is to check your pressure with a gauge. Should be at least 14 psi or so at idle. At 3,000 rpms it should be about 50 or 60 psi. If it is much lower than this, it is very likely that your oil pump pickup screen is clogged (sludged). You should not operate the car at all until it is repaired. It is unlikely that an additive or flush product can adequately clean the pickup. You must remove it to clean it, or replace it.

The reason the oil pressure warning doesn't come until 2k rpms is this: our oil pressure switch has a high threshold compared to other cars. I believe it requires more than 14 psi to open, compared to the usual 5 psi. This is to give you an earlier warning and save the engine/turbo from harm. The issue becomes at very low idle speed and high temp, you may not have that much pressure, even if there is nothing wrong. Audi didn't want false alarms going off all the time so they used this system. The oil pressure warning will only light/sound if the switch is closed (it sees less than 14psi) AND the revs are above 2,000 rpms. Above 2k, you should *always* have enough oil pressure to push the switch open. If you don't, then you get the warning. I hope that made sense. It is quite possible for you to have 0 psi (!) at idle. You will still only get the warning after 2k rpms.

Check out these threads:
http://www.audizine.com/forum/showth...en)&highlight=
http://www.audizine.com/forum/showth...ics&highlight=

[STG3_00_s4]

where do you hook up the oil pressure gauge?

[mdanish]

i have the same problem, yet mine only starts after the engine is warmed up and under 2500 rpm, over that it doesnt come on. replaced a bad rod bearing and problem still persists, i think its the oil pump...

[walky_talky20]

There are 2 places to easily hook up a pressure gauge. This photo shows both. There is a plug on top of the oil filter housing, which is highlighted in red. There is also the port for the factory oil pressure switch on the rear of the oil filter housing, which is in the red box. Both are Metric 10x1.0 threads.

[brockallentaylo]

Ohh PLEASE PLEASE PLEASE Don't drive your car ANYWHERE with that coming on intermittently without verifying oil pressure with a mechanical gage (very very cheap at parts store) you will regret it, save your engine for cheap (remove oil pan and de-sludge) rather than ruining the whole engine.....listen to those lifters at idle, they will tell the story if you are just too lazy to hook up a gage and want to risk it (louder than normal ticking at idle). I don't think the oil light will come on under 2K unless the sender is bad. I have pulled more than 10 oil pans for sludge and this is how they all started (oil light on after 2K but not at idle, lifter noise). If you are getting the light already, don't waste your time with sea foam, that trick should be done before this happens as a preventative measure not after it has been clogged, you are asking too much of sea foam and you shouldn't drive it without proper oil pressure anyhow so there is no right way to do it but verify pressure and pull the pan (not that bad, 5 hour job for me start to finish). SAVE YOUR ENGINE! I buy and sell 1.8t cars all the time because people don't heed the warnings and the only person that wins in that situation is me!

[Dallas09]

For the oil pressure warning light the FIRST step is to check your pressure with a gauge. Should be at least 14 psi or so at idle. At 3,000 rpms it should be about 50 or 60 psi. If it is much lower than this, it is very likely that your oil pump pickup screen is clogged (sludged). You should not operate the car at all until it is repaired. It is unlikely that an additive or flush product can adequately clean the pickup. You must remove it to clean it, or replace it.

The reason the oil pressure warning doesn't come until 2k rpms is this: our oil pressure switch has a high threshold compared to other cars. I believe it requires more than 14 psi to open, compared to the usual 5 psi. This is to give you an earlier warning and save the engine/turbo from harm. The issue becomes at very low idle speed and high temp, you may not have that much pressure, even if there is nothing wrong. Audi didn't want false alarms going off all the time so they used this system. The oil pressure warning will only light/sound if the switch is closed (it sees less than 14psi) AND the revs are above 2,000 rpms. Above 2k, you should *always* have enough oil pressure to push the switch open. If you don't, then you get the warning. I hope that made sense. It is quite possible for you to have 0 psi (!) at idle. You will still only get the warning after 2k rpms.

Check out these threads:
http://www.audizine.com/forum/showth...en)&highlight=
http://www.audizine.com/forum/showth...ics&highlight=

+1, the oil pressure light is only triggered above 2k rpms.

[vrmm]

One hell of a bump! But it's a great thread, so perhaps this will add slightly too that..

So I 'destroyed' the whole front end of my car including oil pan sway bar/subframe brackets, rims, my headlights flew out. All replaced and good to go with a brand new pan. Thing is my pickup tube was bent down and I don't know to what angle side to side, so I bent it back up enough that the pan wouldn't hit it, so I imagine it's almost touching the bottom on the side opposite where the sensor would go in. (Aeb so no sensor) Drain plug side basically.

Anyways I have started it and no noise, drove it around a bit, all good.. But today I went up a hill that's ridiculous even for Seattle. But I make it up the hill, no light, turn onto my street about a minute and a half later and the oil light starts flashing. Right after the hill and maybe during I could hear the valves ticking. But what's confusing me is that I was on flat pavement steady 3kish rpm and minutes later it goes off.

So I pulled an oil cooler line and at idle it was definitely pushing fluid. So I go up to about 3k and it filled a 14oz glass bottle up in like 3 seconds. So it's got pressure (I have a gauge but I have to drive to get it). What my question boils down to is what angle/where exactly in the pan should the pickup tube be sitting? I know it's not clogged, doubt it's my oil pressure sensor since it's never done it before and my valves were audibly chattering. So given the angle of the street I went up (which in the past I've went up no issue) what do you think I should do in reference to the angle/placement of the pickup tube? Is it supposed to be almost on the pan.. To the left or to the right... My oil level was spot on high. I added an additional quart just to be safe and blow out some seals ;) There's no hairline or larger cracks higher up on the tube.. Thoughts?

[walky_talky20]

I would highly advise replacing the pickup with a new one. Fixing a bent pickup tube is not a good plan, even just for the reason of second guessing your repair. They are pretty cheap.