[D's Bimmer]

In the past couple of weeks I have had to add 2 quart's of oil. I can't see any oil dropping under the car. No visible oil in the engine bay at first glance.

Any suggestions as to what might be going on here?

Thanks

[CantCatchMe]

What kind of oil are you using?

[D's Bimmer]

Originally Posted by CantCatchMe

What kind of oil are you using?

The two replacement quarts I used were Castrol Syntec SAE 5W-40 Synthetic. I had these in the garage.

[CantCatchMe]

Originally Posted by D's Bimmer

The two replacement quarts I used were Castrol Syntec SAE 5W-40 Synthetic. I had these in the garage.

Try ditching that oil and try something different which has a better viscosity rate. I switched from the BMW oil to Liqui Moly and it has been better not burning a lot of oil. I had no leaks as well. Motul is a good choice also besides what I used.

[weehe126]

Better viscosity? 5w-40 is what he should be using. I personally use Rotella T6, but a lot of people use Motul as well.

There are way too many things that could be wrong ranging from a bad oil level sensor to a bent rod. Since there is no dipstick I would do an oil change and put in the 6.5qts. This way you know how much is in there. If it keeps saying to add more it's probably the sensor. If after a few days it says to add more it's probably a leak. The belly pan is pretty good at biding leaks, so might want to take it off and see.

[CantCatchMe]

Originally Posted by weehe126

Better viscosity? 5w-40 is what he should be using. I personally use Rotella T6, but a lot of people use Motul as well.

There are way too many things that could be wrong ranging from a bad oil level sensor to a bent rod. Since there is no dipstick I would do an oil change and put in the 6.5qts. This way you know how much is in there. If it keeps saying to add more it's probably the sensor. If after a few days it says to add more it's probably a leak. The belly pan is pretty good at biding leaks, so might want to take it off and see.

I have changed my friends oil multiple times on his N54 and even when he used the same oil as the OP, for some reason it came out very thin compared to my oil using LM. Again, this is from my experience. Also, side note for those who don't know, but BMW uses Shell oil now which a few friends have switched from because of it burning a lot faster and having to add 2 quartz almost after 2,500 miles. They have now switched to Motul with significant less burning of the oil and only add 1 quart every 3,000 miles or so.

[STR8-6IX]

Originally Posted by CantCatchMe

Try ditching that oil and try something different which has a better viscosity rate. I switched from the BMW oil to Liqui Moly and it has been better not burning a lot of oil. I had no leaks as well. Motul is a good choice also besides what I used.

better viscosity rate?

please dont tell me you meant that a thinner oil viscosity will help with his oil burning issue.

OP, try switching to Motul. i heard you will burn less oil with this. the shell rotella stuff that the track guys use is also a good choice.

[aaron_]

I use motul 8100 x-cess 5w40. Change oil every 10,000km (6,000miles?). Never have to top up between changes (owned the car for 1.5years, done 35,000kms in that time)

[bcaz808]

Originally Posted by D's Bimmer

In the past couple of weeks I have had to add 2 quart's of oil. I can't see any oil dropping under the car. No visible oil in the engine bay at first glance.

Any suggestions as to what might be going on here?

Thanks

Could be worn turbo seals, I'd check to see if there's an excessive amount of oil in your intercooler.

[Rob_BMW_PNW]

A bent rod wouldnt cause more oil consumption, a cracked ringland on the piston however will
Easily checked with compression test

Or your turbo is taking a shit, which is rare in a N55, but you said yours is high mileage?

[weehe126]

Originally Posted by Rob_BMW_PNW

A bent rod wouldnt cause more oil consumption, a cracked ringland on the piston however will
Easily checked with compression test

Or your turbo is taking a shit, which is rare in a N55, but you said yours is high mileage?

Lol, trust me a bet rod will cause a large oil consumption. These engine do not follow normal rules. But I do agree, highly doubt the turbo is bad. Had 97k miles on mine (just went ps2), 50k of 20+psi and no oil consumption. Turbo literally looks brand new.

[bbnks2]

Not sure why people are saying it can't be your turbo just because theirs hasn't failed...

80k miles and my turbo is pushing a decent amount of oil. Catch can hasn't caught a damn drop in over a year but there is oil accumulating at the throttle body to the point where it forms droplet's and oozes out from the c-clip. I go through only about 1qt every 5k miles though...

If you don't find excessive oil in chargepipes, and you're confident there is no leak (you've removed the undertray and looked for oil leaks), than you've got some other blowby issue you need to bring the car in for. Oil doesn't just disappear.

The oil/viscosity comments are nonsense and should be ignored. The oil itself isn't your issue.

[weehe126]

Originally Posted by bbnks2

Not sure why people are saying it can't be your turbo just because theirs hasn't failed...

80k miles and my turbo is pushing a decent amount of oil. Catch can hasn't caught a damn drop in over a year but there is oil accumulating at the throttle body to the point where it forms droplet's and oozes out from the c-clip. I go through only about 1qt every 5k miles though...

If you don't find excessive oil in chargepipes, and you're confident there is no leak (you've removed the undergrad and looked for oil leaks), than you've got some other blowby issue. Oil doesn't just disappear.

The oil/viscosity comments are nonsense and should be ignored. The oil itself isn't your issue.

So you have no oil in your inlet pipe after the pcv heater? It's only in the IC pipe after the turbo? If a turbo seal goes bad it dumps oil in the exhaust.

[bbnks2]

Originally Posted by weehe126

So you have no oil in your inlet pipe after the pcv heater? It's only in the IC pipe after the turbo? If a turbo seal goes bad it dumps oil in the exhaust.

Yes, pcv hose is bone dry of oil. However, oil is still making its way into the intake tract.

Under boost, the turbo would blow the oil leaking from the seal into the intake tract. That's where it's burned during normal combustion and produces smoke... my car doesn't smoke at all though because the blowby is pretty minimal in the grand scheme of things and isn't concerning to me other than a valvery cleaning being in my near future.

[Rob_BMW_PNW]

Originally Posted by bbnks2

Not sure why people are saying it can't be your turbo just because theirs hasn't failed...

80k miles and my turbo is pushing a decent amount of oil. Catch can hasn't caught a damn drop in over a year but there is oil accumulating at the throttle body to the point where it forms droplet's and oozes out from the c-clip. I go through only about 1qt every 5k miles though...

If you don't find excessive oil in chargepipes, and you're confident there is no leak (you've removed the undertray and looked for oil leaks), than you've got some other blowby issue you need to bring the car in for. Oil doesn't just disappear.

The oil/viscosity comments are nonsense and should be ignored. The oil itself isn't your issue.

Because a bent rod would make a knocking noise, your oil consumption would be the last thing on your mind

They are still internal combustion engines, they follow the same rules with compression and stroke

[bbnks2]

Originally Posted by Rob_BMW_PNW

Because a bent rod would make a knocking noise, your oil consumption would be the last thing on your mind

They are still internal combustion engines, they follow the same rules with compression and stroke

I think you replied to the wrong post lol... I didn't make any comment about a bent rod. I dont know how anyone could conclude that over the interent. I think his statements are purely based on the guy who posted on n54 tech with high oil consumption. He found out it was caused by a bent rod by chance (no audible noise). His n55 had an upgraded turbo though that he acknowledged was poorly tuned.

Since you replied to me I might as well go ahead and disagree with you though lol. A very slightly bent rod could surely twist the piston enough to allow more oil to blow by the rings than normal... Bent rods frequently cause oil consumption but there are a million other things I'd look at first before I was willing to commit to a new motor.

[Wolf 335]

Originally Posted by CantCatchMe

Try ditching that oil and try something different which has a better viscosity rate. I switched from the BMW oil to Liqui Moly and it has been better not burning a lot of oil. I had no leaks as well. Motul is a good choice also besides what I used.

I can attest to this as well. When using BMW oil from the dealer I would have to top up at least 1L between oil changes. (10,000km)

For a period of time I switched to Amsoil Euro Formula and then Liqui Moly. Both oils eliminated in-between oil change top ups.

Currently on LiquiMoly.

[Rob_BMW_PNW]

Originally Posted by bbnks2

I think you replied to the wrong post lol... I didn't make any comment about a bent rod. I dont know how anyone could conclude that over the interent. I think his statements are purely based on the guy who posted on n54 tech with high oil consumption. He found out it was caused by a bent rod by chance (no audible noise). His n55 had an upgraded turbo though that he acknowledged was poorly tuned.

Since you replied to me I might as well go ahead and disagree with you though lol. A very slightly bent rod could surely twist the piston enough to allow more oil to blow by the rings than normal... Bent rods frequently cause oil consumption but there are a million other things I'd look at first before I was willing to commit to a new motor.

I failed to quote two posts in one comment

"Lol, trust me a bet rod will cause a large oil consumption. These engine do not follow normal rules. But I do agree, highly doubt the turbo is bad. Had 97k miles on mine (just went ps2), 50k of 20+psi and no oil consumption. Turbo literally looks brand new."

I would still disagree more as a bent rod would make a knocking noise and oil loss would be the last thing on your mind.

Comp test would rule out ringlands.

And under your logic if his rod was slightly bent, he wouldnt be losing that much oil, otherwise that bend would be much more than 'slightly' and he would have rod knock

[bahn]

Originally Posted by D's Bimmer

In the past couple of weeks I have had to add 2 quart's of oil. I can't see any oil dropping under the car. No visible oil in the engine bay at first glance.

Any suggestions as to what might be going on here?

Thanks

When you were having the dealer look into your overboost issue didn't they find that you had very low compression on cylinder 6? This should be investigated more as it's probably your cause of increased oil consumption.

[CantCatchMe]

Originally Posted by Wolf 335

I can attest to this as well. When using BMW oil from the dealer I would have to top up at least 1L between oil changes. (10,000km)

For a period of time I switched to Amsoil Euro Formula and then Liqui Moly. Both oils eliminated in-between oil change top ups.

Currently on LiquiMoly.

I made a mistake I thought he was using 5w30. Either way, burning oil and losing consumption does have a lot to do with it. From my experience and friends we switched from the "BMW" now Shell oil to Liqui Moly and I've been impressed when changing the oil to see how it wears after 5-6.5k miles. I would still switch oils to motul or Liqui Moly to see if consumption changes. These guys are talking about a turbo when I would do some testing first before changing parts. At least hoist the car up and take a better look around yourself, if feasible.

[D's Bimmer]

Follow up. I am taking the car in later in the week to look at the oil lose. Haven't lost any more since I topped it up.

Today my low coolant light came on. Took it in to get topped up and it was very low.

Might these possibly be related?

[weehe126]

Eh, my car randomly eats coolant. I can go a few months with out the level changing then have the warning pop up randomly. However, it is common for the expansion tank to crack and leak as well as the drivers side radiator connection. Only place oil and coolant can mix is oil filter housing gasket. So if it is leaking that may also be it.