The case of disappearing oil. I am stumped.

acdHQK713K · 10-06-2011, 03:23 PM

I have been noticing that my car seems to be going through an awful lot of oil lately.

The Problem:
Using the indicator stalk to check the oil I noticed it was 1/4 above the minimum mark. I put in 3/4 of a quart of BMW 5w30 and brought it up to full. A few days later and it was back down to 1/2 of the way to full so I put in the rest of that quart and brought it back up to full. About 300 miles later and the indicator stalk is telling me I am again only 1/4 above the minimum line. So basically one qt gone in roughly 500 miles.

The Car:
2007 335i with AT. 71,500 miles. Oil filter housing gaskets replaced 6k miles ago with no leaks since then.

Filled with BMW 5w30 and mobil 1 0w40.

Mods:
Cobb Tune
UR catless DPs
ETS Intercooler
Forge Diverter valves venting to atmosphere through small K&N breather filters
Injen DCI

Recent Changes/Events:
Track day at Buttonwillow a few weeks ago. It was hot. Oil temps got up into the 280-290s. No limp mode. No problems that day. Started noticing the oil issue a couple days after this, but am not sure there is a connection.

Only mod that has changed in the last 3k miles is that I changed the Forge DVs to vent to air instead of recirculate. Just for the heck of it.

Diagnostic measures:
No codes on the Cobb AP. No SES or limp modes lately.
No oil visualized leaking on the garage floor (I park in the same place every night).
No oil seen dropping from the oil filter housing.
No oil seen in the coolant. Although I have never seen this I would expect it to be obvious.
No blue/white smoke on startup.
Revved the engine while in park to see if I could see any puffs of smoke and didn't see much.
Closed the garage door and revved it to see if I could smell oil burning (super smart I know). There might have been a slight smell of burning oil but nothing that screams she is leaking like a sieve.
Car seems to be running just fine actually. No hiccups.

Potential causes?

1) Maybe my oil level sensor is shot? But it seems most people get a low oil light all of a sudden that doesn't make sense. I am actively watching the sensor tell me the oil is going down so I don't think its the sensor.

2) The car is burning oil but I am just not seeing the visual signs.

3) Car is leaking oil but doesn't do it in my garage.

4) Somehow venting the Forge DVs to atomosphere is causing an issue. A long shot but it's the only thing that has changed recently.

Car is under warranty. Only reason I don't take it in is because 1) I have to take all my mods off and 2) I know they will just fill it up and make me come back when it is low again with no real investigation.

I topped the car off again today. Adding another 1/2 qt. Should I just flush the oil to confirm nothing catastrophic is taking place?

Thoughts?

ETS Michael · 10-06-2011, 05:27 PM

Had the same deal, my turbo's were leaking oil out the back seals.

acdHQK713K · 10-06-2011, 05:44 PM

Quote:

Originally Posted by ETS Michael

Had the same deal, my turbo's were leaking oil out the back seals.

How was the diagnosis made? Was the fix new turbos?

I guess I will just try to document the dropping oil levels before bringing it into the dealer.

ETS Michael · 10-06-2011, 05:50 PM

Oil dripping out of the downpipe. Hopefully this is not your problem, but i'm trying to think of reasons w/o an oil leak and this would be one of the oil scenarios i can think of.

acdHQK713K · 10-06-2011, 05:54 PM

Quote:

Originally Posted by ETS Michael

Oil dripping out of the downpipe. Hopefully this is not your problem, but i'm trying to think of reasons w/o an oil leak and this would be one of the oil scenarios i can think of.

Thanks for the help.

MUNDA · 10-06-2011, 07:39 PM

Why dont you just do an oil change? See how much oil comes out, that way you can tell if the oil sensor is bad. You have no other visual signs that your car is losing oil.

acdHQK713K · 10-06-2011, 08:42 PM

Quote:

Originally Posted by MUNDA

Why dont you just do an oil change? See how much oil comes out, that way you can tell if the oil sensor is bad. You have no other visual signs that your car is losing oil.

Probably not the most accurate way of measuring oil. I am sure there will still be some left in the pan.

MUNDA · 10-06-2011, 11:35 PM

Quote:

Originally Posted by Stangorang

Probably not the most accurate way of measuring oil. I am sure there will still be some left in the pan.

You are completely correct, however, since your oil level sensor may be bad, better be on the safe side and change the oil. If all is good, you get a oil change done in the process

tibra1 · 10-07-2011, 12:02 AM

I think the majority of oil issues are usually related to the turbo or oil housing gaskets..unless you have extreme mileage its doubtful it from the block or valve cover..how many miles on your car?

acdHQK713K · 10-07-2011, 12:55 PM

Quote:

Originally Posted by tibra1

I think the majority of oil issues are usually related to the turbo or oil housing gaskets..unless you have extreme mileage its doubtful it from the block or valve cover..how many miles on your car?

71k miles. Both oil filter gaskets replaced recently due to leaking. Turbos replaced at 40k miles for WG rattle.

If the turbos really are leaking could I theoretically disconnect the DPs from the rear exhaust section and find oil? Or does the car need to be running or under boost for the turbos to leak?

tibra1 · 10-07-2011, 03:45 PM

Quote:

Originally Posted by Stangorang

71k miles. Both oil filter gaskets replaced recently due to leaking. Turbos replaced at 40k miles for WG rattle.

If the turbos really are leaking could I theoretically disconnect the DPs from the rear exhaust section and find oil? Or does the car need to be running or under boost for the turbos to leak?

Thats a great question Im sure any residue on the DPs will give you an indication as to the full boost..I would suspect you would see "more" oil but if there is a leak in the seals it would prolly leak w the DPs off and at idle..although a slow leak

acdHQK713K · 11-06-2011, 07:09 PM

In 1k miles I lost 1/2 a qt. Still can't find a leak and still don't have noticeable smoke.

What's the next move here? Dealer? Wait it out?

tibra1 · 11-06-2011, 07:37 PM

Excessive oil consumption is not something you want to "wait out"..indy shop or dealer...find out whats happening..if you still have cats on your exhaust you could be burning oil and not seeing it..b/c cats mask it.

acdHQK713K · 11-06-2011, 07:41 PM

Quote:

Originally Posted by tibra1

Excessive oil consumption is not something you want to "wait out"..indy shop or dealer...find out whats happening..if you still have cats on your exhaust you could be burning oil and not seeing it..b/c cats mask it.

I guess what I was asking is that consumption rate good enough for a dealer to take it seriously.

tibra1 · 11-06-2011, 07:43 PM

Quote:

Originally Posted by Stangorang

I guess what I was asking is that consumption rate good enough for a dealer to take it seriously.

Yes..1/2 quart in 1,000 miles..IMO is serious..you have to understand these type of problems can only get worse not better.

acdHQK713K · 11-06-2011, 07:46 PM

Quote:

Originally Posted by tibra1

Yes..1/2 quart in 1,000 miles..IMO is serious..you have to understand these type of problems can only get worse not better.

I agree. Just read in previous posts that dealers were turning people away if it was less than 1qt/1000 miles.

Probably the turbo seals going out....again

tibra1 · 11-06-2011, 07:49 PM

Quote:

Originally Posted by Stangorang

I agree. Just read in previous posts that dealers were turning people away if it was less than 1qt/1000 miles.

Probably the turbo seals going out....again

I would stretch the truth a bit...tell the dealer you're going thru a quart every 500 miles..as long as they find the problem thats whats important.

samchoi604 · 11-07-2011, 04:13 AM

Quote:

Originally Posted by ETS Michael

Had the same deal, my turbo's were leaking oil out the back seals.

I have heard of this several times. What causes this? Is it just wear n' tear, or perhaps poor installation of the downpipes can also lead to this?

acdHQK713K · 11-23-2011, 11:25 PM

Well my car finally started smoking today. Was stuck in traffic and after about 20 mins I started to notice blue smoke coming out the rear.

It seemed to go away as the RPMs increased and got worse when I would sit idle for a bit and start back up.

Looks like a certain case of blown seals on the turbos.

Peabody · 11-24-2011, 01:21 AM

Hi Stangorang,
Had identical problem with our 320i in Australia. I was adding oil at ridiculous intervals and after one huge ploom of blue smoke decided to drop the oil and see what came out.
The engine only holds 4 1/4 litres and out came 7+ litres, so there was no oil leak and the engine wasn't consuming same.
So I removed the bottom tray and then removed the oil sensor, BMW quoted $675...Ebay $160..for a new sensor no labour. There is a small pinhole at the top of the sensor and it appeared to be clogged. I gave the unit a really good clean and rinse and reinstalled the same unit but purchased ($25) a new O ring for the base.
Car has since done around 600kms and no further problems. Hope this is of some help...Peabody

acdHQK713K · 11-24-2011, 01:05 PM

Quote:

Originally Posted by Peabody

Hi Stangorang,
Had identical problem with our 320i in Australia. I was adding oil at ridiculous intervals and after one huge ploom of blue smoke decided to drop the oil and see what came out.
The engine only holds 4 1/4 litres and out came 7+ litres, so there was no oil leak and the engine wasn't consuming same.
So I removed the bottom tray and then removed the oil sensor, BMW quoted $675...Ebay $160..for a new sensor no labour. There is a small pinhole at the top of the sensor and it appeared to be clogged. I gave the unit a really good clean and rinse and reinstalled the same unit but purchased ($25) a new O ring for the base.
Car has since done around 600kms and no further problems. Hope this is of some help...Peabody

If I had the smoking issue shortly after adding oil I would suspect it is the same problem as you had. But it's been some time since I added oil so I bet it's the seals.

acdHQK713K · 11-24-2011, 02:41 PM

Actually I think you are right. I just tested the car to see if I could get it to smoke. It didn't smoke but it did tell me all of a sudden that the oil level is 100% full. Yesterday when it was smoking it was only 1/2 to full. I didn't add oil.

Looks like I will be replacing the oil level sensor after I check to see how much oil is in the pan.

10-06-2011, 03:23 PM	#1
acdHQK713K Major 231 Rep 1,473 Posts Drives: Car Join Date: Mar 2010 Location: USA iTrader: (9)	The case of disappearing oil. I am stumped. I have been noticing that my car seems to be going through an awful lot of oil lately. The Problem: Using the indicator stalk to check the oil I noticed it was 1/4 above the minimum mark. I put in 3/4 of a quart of BMW 5w30 and brought it up to full. A few days later and it was back down to 1/2 of the way to full so I put in the rest of that quart and brought it back up to full. About 300 miles later and the indicator stalk is telling me I am again only 1/4 above the minimum line. So basically one qt gone in roughly 500 miles. The Car: 2007 335i with AT. 71,500 miles. Oil filter housing gaskets replaced 6k miles ago with no leaks since then. Filled with BMW 5w30 and mobil 1 0w40. Mods: Cobb Tune UR catless DPs ETS Intercooler Forge Diverter valves venting to atmosphere through small K&N breather filters Injen DCI Recent Changes/Events: Track day at Buttonwillow a few weeks ago. It was hot. Oil temps got up into the 280-290s. No limp mode. No problems that day. Started noticing the oil issue a couple days after this, but am not sure there is a connection. Only mod that has changed in the last 3k miles is that I changed the Forge DVs to vent to air instead of recirculate. Just for the heck of it. Diagnostic measures: No codes on the Cobb AP. No SES or limp modes lately. No oil visualized leaking on the garage floor (I park in the same place every night). No oil seen dropping from the oil filter housing. No oil seen in the coolant. Although I have never seen this I would expect it to be obvious. No blue/white smoke on startup. Revved the engine while in park to see if I could see any puffs of smoke and didn't see much. Closed the garage door and revved it to see if I could smell oil burning (super smart I know). There might have been a slight smell of burning oil but nothing that screams she is leaking like a sieve. Car seems to be running just fine actually. No hiccups. Potential causes? 1) Maybe my oil level sensor is shot? But it seems most people get a low oil light all of a sudden that doesn't make sense. I am actively watching the sensor tell me the oil is going down so I don't think its the sensor. 2) The car is burning oil but I am just not seeing the visual signs. 3) Car is leaking oil but doesn't do it in my garage. 4) Somehow venting the Forge DVs to atomosphere is causing an issue. A long shot but it's the only thing that has changed recently. Car is under warranty. Only reason I don't take it in is because 1) I have to take all my mods off and 2) I know they will just fill it up and make me come back when it is low again with no real investigation. I topped the car off again today. Adding another 1/2 qt. Should I just flush the oil to confirm nothing catastrophic is taking place? Thoughts? Last edited by acdHQK713K; 10-06-2011 at 05:01 PM..
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10-06-2011, 05:27 PM	#2
ETS Michael Major 76 Rep 1,155 Posts Drives: 335i Join Date: May 2009 Location: Vancouver, WA iTrader: (4)	Had the same deal, my turbo's were leaking oil out the back seals.
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10-06-2011, 05:50 PM	#4
ETS Michael Major 76 Rep 1,155 Posts Drives: 335i Join Date: May 2009 Location: Vancouver, WA iTrader: (4)	Oil dripping out of the downpipe. Hopefully this is not your problem, but i'm trying to think of reasons w/o an oil leak and this would be one of the oil scenarios i can think of.
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10-06-2011, 07:39 PM	#6
MUNDA New Member 0 Rep 7 Posts Drives: 2006 BMW 325i Join Date: Oct 2011 Location: Calgary iTrader: (0)	Why dont you just do an oil change? See how much oil comes out, that way you can tell if the oil sensor is bad. You have no other visual signs that your car is losing oil.
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10-07-2011, 12:02 AM	#9
tibra1 Banned 129 Rep 6,773 Posts Drives: 2011 ZCP M3 - 2007 335i crashd Join Date: Apr 2009 Location: NYC iTrader: (4)	I think the majority of oil issues are usually related to the turbo or oil housing gaskets..unless you have extreme mileage its doubtful it from the block or valve cover..how many miles on your car?
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11-06-2011, 07:09 PM	#12
acdHQK713K Major 231 Rep 1,473 Posts Drives: Car Join Date: Mar 2010 Location: USA iTrader: (9)	In 1k miles I lost 1/2 a qt. Still can't find a leak and still don't have noticeable smoke. What's the next move here? Dealer? Wait it out?
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11-06-2011, 07:37 PM	#13
tibra1 Banned 129 Rep 6,773 Posts Drives: 2011 ZCP M3 - 2007 335i crashd Join Date: Apr 2009 Location: NYC iTrader: (4)	Excessive oil consumption is not something you want to "wait out"..indy shop or dealer...find out whats happening..if you still have cats on your exhaust you could be burning oil and not seeing it..b/c cats mask it.
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11-23-2011, 11:25 PM	#19
acdHQK713K Major 231 Rep 1,473 Posts Drives: Car Join Date: Mar 2010 Location: USA iTrader: (9)	Well my car finally started smoking today. Was stuck in traffic and after about 20 mins I started to notice blue smoke coming out the rear. It seemed to go away as the RPMs increased and got worse when I would sit idle for a bit and start back up. Looks like a certain case of blown seals on the turbos.
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11-24-2011, 01:21 AM	#20
Peabody New Member 1 Rep 7 Posts Drives: 320i E90 4 cyl Join Date: Oct 2011 Location: Australia iTrader: (0)	Hi Stangorang, Had identical problem with our 320i in Australia. I was adding oil at ridiculous intervals and after one huge ploom of blue smoke decided to drop the oil and see what came out. The engine only holds 4 1/4 litres and out came 7+ litres, so there was no oil leak and the engine wasn't consuming same. So I removed the bottom tray and then removed the oil sensor, BMW quoted $675...Ebay $160..for a new sensor no labour. There is a small pinhole at the top of the sensor and it appeared to be clogged. I gave the unit a really good clean and rinse and reinstalled the same unit but purchased ($25) a new O ring for the base. Car has since done around 600kms and no further problems. Hope this is of some help...Peabody
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11-24-2011, 02:41 PM	#22
acdHQK713K Major 231 Rep 1,473 Posts Drives: Car Join Date: Mar 2010 Location: USA iTrader: (9)	Actually I think you are right. I just tested the car to see if I could get it to smoke. It didn't smoke but it did tell me all of a sudden that the oil level is 100% full. Yesterday when it was smoking it was only 1/2 to full. I didn't add oil. Looks like I will be replacing the oil level sensor after I check to see how much oil is in the pan.
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