2.0T Low Oil Pressure after limp mode

[Knavishmammal]

I’ve been struggling to get my Audi out of limp mode (epc) and after replacing my fuel filter, high pressure fuel pump and cam follower it ran a little better but still wouldn’t get above 3k rpm. I had open circuits codes for the N75, fuel pressure regulator and evap system. I replaced the N75 and it didn’t change anything so then I realized it was truly an electric issue and turns out it was the 15 amp fuse inside the ecu that was blown.

Upon replacing said fuse car started up instantly and sounded normal so I took it on a test drive and every time it would start to build boost I would hear a thunk or a bad noise coming from the turbo side and was persistent until it warmed up and went away. After about 30 mins into my test drive the “red oil can of death” popped up and I put a quart of oil while it was running and had a hard time taking off the oil cap??? That didn’t fix the pressure and ended up turning the car off 3 times within a mile to make it home, would turn it off immediately after the oil can turned back on.

So I thought my previous issue was mechanical due to the cam follower being completely busted through and needed a new hpfp and intake cam(I have one sitting on the shelf waiting to install if needed) and I was aware of the fact that after all this my oil pump will go bad from all the metal but I’m not sure if that was even the problem so it still a possibility that’s what is causing my low pressure?

If I do end up taking off the oil pan and dropping the subframe is it possible to clean it out and get it back to normal? I’ve been reading something about diesel but I have no idea what that does in terms of cleaning.

I’m sorry for my format I’m trying to work on it lol.

[Theiceman]

no offense but lets stay away from what you think right now and just stick with what you know ... " just the facts Ma'am , just the facts" <-- I may have just dated myself.

okay from what i have read.
1. you heard a noise coming from the turbo side of the motor
2. red oil can light came on
3. oil cap difficult to remove .

so , not sure why you dumped a quart of oil in the car , what was the oil level like when you checked it ? did you just dump a quart in without checking oil level before or after ?
oil cap difficult to remove ... yes there is significant vacuum at idle on the 2.0T . a lot more than on the 1.8, however the oil cap should NOT be difficult to remove. If you are pulling way to much vacuum in the cranckase it can in fact effect your oil pressure throwing low oil pressure warnings. If you have access to a vacuum gauge i would check to see what that vacuum is at idle through the dipstick. If you dont have the means to do that before doing anything i would consider the PCV assembly ( along with the breather tube ) Maybe someone can check theirs to give you a baseline ( my b7 is off site right now ).

If the vacuum is fine or you replce the PCV ( with the correct version ) . Next step is to get an oil pressure gauge on your engine and lets see what the oil pressure is running... baby steps..

[Knavishmammal]

no offense but lets stay away from what you think right now and just stick with what you know ... " just the facts Ma'am , just the facts" <-- I may have just dated myself.

okay from what i have read.
1. you heard a noise coming from the turbo side of the motor
2. red oil can light came on
3. oil cap difficult to remove .

so , not sure why you dumped a quart of oil in the car , what was the oil level like when you checked it ? did you just dump a quart in without checking oil level before or after ?
oil cap difficult to remove ... yes there is significant vacuum at idle on the 2.0T . a lot more than on the 1.8, however the oil cap should NOT be difficult to remove. If you are pulling way to much vacuum in the cranckase it can in fact effect your oil pressure throwing low oil pressure warnings. If you have access to a vacuum gauge i would check to see what that vacuum is at idle through the dipstick. If you dont have the means to do that before doing anything i would consider the PCV assembly ( along with the breather tube ) Maybe someone can check theirs to give you a baseline ( my b7 is off site right now ).

If the vacuum is fine or you replce the PCV ( with the correct version ) . Next step is to get an oil pressure gauge on your engine and lets see what the oil pressure is running... baby steps..

Thank you I’ll try to not use I think. Is a PCV system something I can get from the junkyard or should I get a new one from ecs?

[Knavishmammal]

And I was a tad low on oil before I poured in the quart and it brought me close to max hot. I’m not sure if the reading is supposed to be old or hot.

[tractoman]

Thank you I’ll try to not use I think. Is a PCV system something I can get from the junkyard or should I get a new one from ecs?

Get a new one. OEM. Pelican Parts has them as does FCP and many other online retailers. Get a new gasket too. PCV is very easy to replace on these cars. What year is the car? There are two variations of pcv and they have to do with the check valve or lack there of in the breather tube. Make sure you get the proper one.

[Knavishmammal]

Get a new one. OEM. Pelican Parts has them as does FCP and many other online retailers. Get a new gasket too. PCV is very easy to replace on these cars. What year is the car? There are two variations of pcv and they have to do with the check valve or lack there of in the breather tube. Make sure you get the proper one.

I have a 2007, is this the later or earlier model when looking for parts?

[Jayz691]

I have a 2007, is this the later or earlier model when looking for parts?

Late model. Should have "P" revision PCV. But can check rear breather pipe, it should have a black check valve where it connects to the rubber hose(that connects to VC). If for some reason it don't, then get an "R" revision PCV. Always go genuine with the PCV. FCP has lifetime replacement, so only pay once.

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[Theiceman]

If you get the later one get a new breather pipe too as it's the check valve that may be the issue.

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[Knavishmammal]

Thank you guys for all the advice :)

After replacing my pcv should I still inspect the oil pick up with having a busted follower? I got a magnetic plug from ecs and am curious on how much metal is on it. I am towing the car on Monday to my parents and won’t be able to inspect much since I live in an apartment. It’s only 6 miles away but I don’t want to put more stress on it.

[Theiceman]

Thank you guys for all the advice :)

After replacing my pcv should I still inspect the oil pick up with having a busted follower? I got a magnetic plug from ecs and am curious on how much metal is on it. I am towing the car on Monday to my parents and won’t be able to inspect much since I live in an apartment. It’s only 6 miles away but I don’t want to put more stress on it.

That's a nightmare job. I would check oil pressure next after replacing pcv

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[Knavishmammal]

That's a nightmare job. I would check oil pressure next after replacing pcv

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Is the best way to check the pressure with a mechanical gauge through the pressure switch?

[tractoman]

Is the best way to check the pressure with a mechanical gauge through the pressure switch?

Yes, mechanical gauge connected where the switch goes, behind the oil cooler.

[mc_hotmail]

My bet is on the oil pressure switch being correct. Three of us investigated low oil pressure issues in recent months, none due to bad (cheap) pressure switch. We all had to at least remove the oil pan, clean/replace oil pickup or the entire oil pump. Get ready for that.

[XLR8 Craig]

My bet is on the oil pressure switch being correct. Three of us investigated low oil pressure issues in recent months, none due to bad (cheap) pressure switch. We all had to at least remove the oil pan, clean/replace oil pickup or the entire oil pump. Get ready for that.

We had an employee who purchased a B7 A4 that was having some oil pressure issues as well. Upon breakdown the pickup tube was partially clogged (with pieces of a follower from a previous failure the owner had fixed incorrectly), the oil pump assembly had seized, and the balance shaft sized up as well. Was quite the headache but he got the car for a steal.

Hopefully OPs problem isn't as serious, but to wrap up the thought: I would also bet the oil pressure sensor is functioning and there is an underlying issue. Still worth confirming pressure with a mechanical gauge, but pulling the pan and doing a little digging wouldn't be a bad next step after that.

Best of luck! Feel free to send me a PM if you need some parts pricing.

There's another low oil pressure thread on the B7 forums here: https://www.audizine.com/forum/showt...pressure-issue

[Knavishmammal]

We had an employee who purchased a B7 A4 that was having some oil pressure issues as well. Upon breakdown the pickup tube was partially clogged (with pieces of a follower from a previous failure the owner had fixed incorrectly), the oil pump assembly had seized, and the balance shaft sized up as well. Was quite the headache but he got the car for a steal.

Hopefully OPs problem isn't as serious, but to wrap up the thought: I would also bet the oil pressure sensor is functioning and there is an underlying issue. Still worth confirming pressure with a mechanical gauge, but pulling the pan and doing a little digging wouldn't be a bad next step after that.

Best of luck! Feel free to send me a PM if you need some parts pricing.

There's another low oil pressure thread on the B7 forums here: https://www.audizine.com/forum/showt...pressure-issue

Sounds like I’m heading down the same road but I’m not sure if it’s seized up yet cause I can get it a couple blocks before it would throw the light and that’s my reasoning for wanting to inspect the pick up.

[Jayz691]

Sounds like I’m heading down the same road but I’m not sure if it’s seized up yet cause I can get it a couple blocks before it would throw the light and that’s my reasoning for wanting to inspect the pick up.

Thats only cuz pressure drops as oil heats up..

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[mc_hotmail]

... cause I can get it a couple blocks before it would throw the light

There is no coincidence here. That light comes on one time is one time too many. The 2nd and 3rd time just starving the engine of oil and grind down a bearing or journal somewhere or everywhere.

[Kevin C]

Another possibility is that the pressure relief valve in the pump is hanging up on a chunk of cam follower. For good oil pressure when hot it needs to be fully closed. It may have opened when the oil was cold and got hung up on some debris. When you pull the pan to inspect the pickup check to make sure the relief valve.

[Knavishmammal]

So I finally got the car to my parents house and am kinda confused on where the sensor is. I have a feeling I’ve been looking at 1.8T diagrams... the only thing I can think that it is right behind the oil cooler, thing is size of my hand and right above the filter. Is that the sensor?

[Theiceman]

you must have tiny hands...

it bolts to the back of the oil filter housing towards the firewall and has a black connector.

[esandes]

Some sketchy advice here. Wow.