Losing oil with no leak and no smoke visible

Tiny
VISI1100
  • MEMBER
  • 2002 AUDI A4
  • 2.0L
  • 4 CYL
  • 2WD
  • MANUAL
  • 100 MILES
I have a problem with engine losing oil but no leak and no smoke visible.

A couple of weeks before I changed my all engine cause I had an overheating problem and losing a lot of oil without leaking but a lot smoke and losing power.
With the new engine I can see the power difference driving in mountains with 4 people on it is everything perfect in high gears and low rpm but still the same problem with oil. I'm losing oil. Every 100km my car dashboard will get on the yellow light with oil figure and under it is written "min".
The first time using this new engine I drove for around 500km and I have lose around 200 ml oil and I noticed a lot of oil on spark plugs so I changed directly the valve cover gasket, but still the same I am losing oil but no leaking no smoke from exhaust and if my car is started and I open the oil cap is nothing to suspect no oil coming up everything work fine.
My question is, what can be the problem?
And if I use an air oil separator or oil catch can do I save oil or I will lose the same oil amount?
Thank you
My car listed above B6 with engine 2.0ALT. It doesn't have turbo or FSI is simple 2.0 with "ALT" engine code.

Sorry for my poor English.
Friday, June 5th, 2020 AT 2:16 PM

38 Replies

Tiny
JACOBANDNICKOLAS
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Hi,

Do something for me. With the engine running, open the hood and remove the oil fill cap. Let me know if there is a lot of pressure blowing out. Be careful because it could spit some oil out.

Joe
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Friday, June 5th, 2020 AT 8:48 PM
Tiny
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Thank you for your answer.
I have done that but no nothing goes out no oil nothing. Everything works in the same way that it worked before I removed the cap.
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Tuesday, June 9th, 2020 AT 11:51 AM
Tiny
JACOBANDNICKOLAS
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The only thing I can say then is that the oil rings must be worn enough to allow oil to be burned but the catalytic converter is taking care of it. If there are no leaks, no excessive blow by, no mixing with coolant, there is no place else for it to go. How many miles are on the engine?
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Tuesday, June 9th, 2020 AT 8:51 PM
Tiny
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Around 100,000 miles.
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Friday, June 12th, 2020 AT 3:59 PM
Tiny
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I have done rings on my old engine and valves etc, but it was still burning oil that's why I still is engine problem because a lot of 2.0 alt engine are complaining on internet and some of them say they have small oil amount burning now because they have modified the hoses for not having a lot of air pressure.
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Friday, June 12th, 2020 AT 4:02 PM
Tiny
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If rings are replaced, you have to confirm the cylinder walls are not out of round or worn beyond what the rings can handle. However, if the engine is running good, then the compression rings are doing their job. Plus, you indicated no blow by when you removed the oil fill cap.
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Friday, June 12th, 2020 AT 11:17 PM
Tiny
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So only rings?
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Saturday, June 13th, 2020 AT 3:37 AM
Tiny
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If compression is good, there are no leaks, no smoke from the exhaust, I can't think of anything else that would cause it. If there was a puff of blue smoke on start up, that could indicate valve seals, but that isn't happening. Also, there is no oil mixing with the cooling system, so it's not a head gasket. Honestly, when you first asked, I suspected you would find excessive blow by when you opened the oil cap. I have seen that force oil vapors through the PCV system which can be burned without realizing there is a problem. However, when you checked, you said there was no air coming out of the fill.
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Saturday, June 13th, 2020 AT 7:02 PM
Tiny
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No oil or smoke coming out from oil cap. So oil catch can will not be a help? I have noticed something today coolant level was at minimum so has lost a little coolant cause before it was between min and max level. I didn't told that my car work on gpl too. But the oil consumption is the same for gpl or petrol. I have looked those days and it "eat" around 1l for every 1,000 km but the oil light on dash board come every 99.9km.
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Sunday, June 14th, 2020 AT 6:56 AM
Tiny
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The only thing I can think is that it is getting burned and the emissions system is hiding it. That is excessive usage. I wish I had a better answer for you.

As far as removing the oil cap, I needed to know if there was air coming from it not oil. Did you notice that at all?

Joe
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Sunday, June 14th, 2020 AT 4:45 PM
Tiny
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I think I didn't understand the exact question.
If you ask if air pressure coming out from oil cap when I remove it I think yes. Here I am attacking a video of that prove.
And really thanks broo for your answers.
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Friday, June 19th, 2020 AT 9:34 AM
Tiny
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Ps- I never found out if this car has or not PCV valve.
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Friday, June 19th, 2020 AT 9:36 AM
Tiny
VISI1100
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And today on OBD reader it say has a problem with o2 sensor bank1 but no check engine light and not sure if has to do with spark plugs cause I need to change all 4 spark plugs cause 1 of them does not work good it shake some time on parking position.
Noticed some coolant losing but maybe cause it work on high temperature cause like I have seen before and after changing the thermostat it work around 96 grad Celsius up to 102grad Celsius in city and around 85grad Celsius on highway and usually I drive in traffic.
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Friday, June 19th, 2020 AT 9:40 AM
Tiny
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Hi,

That looks like a good bit of pressure coming out. The crankcase breather (PCV) is mounted to the valve cover. I have attached a (poor) pic of the hose running to it. Check to make sure that is attached and not plugged. I copied a pic of what you sent me and circled where it attaches. See pic 2.

As far as the o2 sensor, can you tell me the code? I need to interpret what is happening.

Joe
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Friday, June 19th, 2020 AT 6:23 PM
Tiny
VISI1100
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Here about o2 sensor code and other OBD data.
That air pressure from oil cap is a problem?
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Saturday, June 20th, 2020 AT 11:39 AM
Tiny
JACOBANDNICKOLAS
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Hi,

The sensor issue is a circuit related problem. Chances are the wiring at the sensor plug is corroded, damaged, or loose. Check that.

As far s the air coming from the engine, some is normal. That seems excessive but I'm not there to confirm. Did you check the PCV (breather) to make sure it is not blocked?

Joe
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Saturday, June 20th, 2020 AT 9:20 PM
Tiny
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I'm not sure how this breather work. There was a lot of oil but seems like air can enter and go out on other side pipe.
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Sunday, June 21st, 2020 AT 2:00 AM
Tiny
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About o2 sensor any idea how to know if it is damaged?
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Sunday, June 21st, 2020 AT 2:00 AM
Tiny
JACOBANDNICKOLAS
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Hi,

The breather allows crankcase air to exit the engine and be recycled through the intake. If there was a lot of oil in the hose, I think we found where the oil is going. It isn't uncommon for small amounts, but I have a feeling that oil vapors are getting sucked back through the intake a being burned without you even seeing it from the exhaust.

As far as the O2 sensor, it is a circuit related issue, so here is what to do.

If you look at the first pic I attached, the pin designation is indicated.

1) Connect multi-meter between terminal 1 and 5 for voltage measurement.
2) Switch ignition on.
3) Specified value: 0,400. 0.500 V.

If the aforementioned values are met, replace the sensor. If they are not met, check to make sure there isn't a damaged wire.

Let me know,
Joe
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Sunday, June 21st, 2020 AT 8:18 PM
Tiny
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Sorry for my late response. I haven't been on internet rgis time family problems sorry.
The o2 sensor connected positive to terminal 1 and negative to terminal 5 with ignition on show 0.48 and with ignition off it show 0.4.
Do I need to change the PCV or just adding a oil catch can?
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Tuesday, June 30th, 2020 AT 1:33 PM

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