[NoPwrOvrMe]

Not sure if anyone really posted about this, every time I would search it would show all "OIL" threads and posts...

Anyways I have a high millage 07 335i E90 with 117K Miles and have noticed sluggishness, smoke, burning oil, knocking and seen engine sludge.

Before changing my oil I checked how it looked through the filter and it was fairly dark with 2K miles on it. I then added Motor Medic by Gunk not the turbo specific one but the regular one. After using Motor Medic for 5 minutes I immediately drained the oil and it was pitch black.

After it completely drained I plugged the drain plug, added a new filter and put in 6 qts of new 0w-40 oil and 1 qt of Marvel's Mystery Oil. Immediately I noticed the car is more responsive and not knocking as loud.

I've driven the car with Mystery Oil in it for about 200 miles now and have had no problems. The car practically runs as if it were new besides for the faint knocking. I then checked the oil and it was already dark showing that the Mystery Oil is doing it's job, or I just have a shit load of sludge buildup. I will be doing another oil change tomorrow or friday to see how much gunk I got and repeat for another 500 miles.

[NoPwrOvrMe]

Did another oil change today checked filter and it was dark brown, used Motor Medic before draining oil and again it was pitch black when drained.

Once again after all the oil completely drained I added 6 qts of 0w-40 and 1 qt of Mystery Oil. Everything is still running smooth but this time it's quieter then before. I will repeat this process every fill-up if the filter looks dark brown, once it starts to clear out I'll stop.

[Three_thirty_I]

That's good to hear!

What sort of oil service intervals has the car had through the years?

[NoPwrOvrMe]

Originally Posted by Three_thirty_I

That's good to hear!

What sort of oil service intervals has the car had through the years?

oil change every 3K miles, occasionally 5K when I get really busy with my work schedule. I bought the car used in 2012 and the previous owner took it to BMW for all the "services" but when I checked it was OLD oil broken slush filter and sludge everywhere.

[Three_thirty_I]

Originally Posted by NoPwrOvrMe

oil change every 3K miles, occasionally 5K when I get really busy with my work schedule. I bought the car used in 2012 and the previous owner took it to BMW for all the "services" but when I checked it was OLD oil broken slush filter and sludge everywhere.

You most likely bought it "pre-sludged" thanks to BMW service intervals. What also works well to deal with sludge gently is some ATF added after draining about a litre of the existing old oil, drive the car gently for a while, then replace with fresh oil.

[NoPwrOvrMe]

Originally Posted by Three_thirty_I

You most likely bought it "pre-sludged" thanks to BMW service intervals. What also works well to deal with sludge gently is some ATF added after draining about a litre of the existing old oil, drive the car gently for a while, then replace with fresh oil.

Yes as I said before there was a crap load of sludge when I bought it. When I bought it I did an engine flush as well as put diesel in the engine overnight. The diesel cleaned out a lot of gunk the next morning. I assumed it was clean after that because my oil was consistently clean for about 3K miles. But I recently had a valve cover leak and when I did that I saw a crap load of sludge still, so decided to start running some engine flush again.

[Three_thirty_I]

Originally Posted by NoPwrOvrMe

Yes as I said before there was a crap load of sludge when I bought it. When I bought it I did an engine flush as well as put diesel in the engine overnight. The diesel cleaned out a lot of gunk the next morning. I assumed it was clean after that because my oil was consistently clean for about 3K miles. But I recently had a valve cover leak and when I did that I saw a crap load of sludge still, so decided to start running some engine flush again.

The diesel trick works, but needs to be done carefully like you did. The ATF is a bit more safe since it is more gradual, and the ATF still allows the oil to have proper lubrication properties. Hopefully these flushes will completely rid the engine of any remaining sludge, and prevent it from building up for whatever reason.

[NoPwrOvrMe]

Originally Posted by Three_thirty_I

The diesel trick works, but needs to be done carefully like you did. The ATF is a bit more safe since it is more gradual, and the ATF still allows the oil to have proper lubrication properties. Hopefully these flushes will completely rid the engine of any remaining sludge, and prevent it from building up for whatever reason.

Agreed. There was so much sludge I thought about buying a new low mileage engine.... Haha. I'll try the at next time, main reason I use mystery oil is that I get it for $3 a quart, less if I buy in a case. I also have friends that are pilots who have them in drums...

Update : checked the oil filter after 50 miles and it's already a dark golden brown.... Looks like I'll be doing an oil change every other day haha.

[Efthreeoh]

I find this thread interesting. Did you verify the previous owner had regular service done at BMW and used a good quality oil? And how was the car driven? I think your methodology of evaluating the color of the oil filter after it's been used for a few hundred miles is giving you a false negative. My N52 saw 17,500 mile OCIs from new to 221,000. After 221K I've switched to a 10,000 mile OCI (BMW recommends 7,500 once the CBS oil monitor system goes defunct). I've looked though the oil fill in the valve cover, looked in the VANOS solenoid holes, and looked into the oil pan through the oil sensor hole, and haven't found any traces of sludge anywhere. If only ever used BMW oil and OE filter shipped as a oil change kit from Tischer.

[NoPwrOvrMe]

Originally Posted by Efthreeoh

I find this thread interesting. Did you verify the previous owner had regular service done at BMW and used a good quality oil? And how was the car driven? I think your methodology of evaluating the color of the oil filter after it's been used for a few hundred miles is giving you a false negative. My N52 saw 17,500 mile OCIs from new to 221,000. After 221K I've switched to a 10,000 mile OCI (BMW recommends 7,500 once the CBS oil monitor system goes defunct). I've looked though the oil fill in the valve cover, looked in the VANOS solenoid holes, and looked into the oil pan through the oil sensor hole, and haven't found any traces of sludge anywhere. If only ever used BMW oil and OE filter shipped as a oil change kit from Tischer.

Yes if you read through the thread the previous owner took it to bmw for all services with records. As you know bmw is shit with their services and most likely didn't even do them. Also their recommended 15k service interval is Bull. Every car I've owned I've done 3k intervals. As bmws naturally burn a lot of oil a 15k interval would build up tons of sludge overtime. This is the first car out of 6 others that has had sludge problems. Also this is a n54 which has more known oil issues to include a lot of oil burn off and sludge build up. Also like I said in the thread I opened my valve cover to change the gasket and found a ton of sludge.

How is looking through the oil filter a false negative when I clearly stated when I drained it after it was pitch black? Also "looking through holes" doesn't show anything. If you want to see real sludge take your valve cover or oil pan completely off.

[Efthreeoh]

Originally Posted by NoPwrOvrMe

Yes if you read through the thread the previous owner took it to bmw for all services with records. As you know bmw is shit with their services and most likely didn't even do them. Also their recommended 15k service interval is Bull. Every car I've owned I've done 3k intervals. As bmws naturally burn a lot of oil a 15k interval would build up tons of sludge overtime. This is the first car out of 6 others that has had sludge problems. Also this is a n54 which has more known oil issues to include a lot of oil burn off and sludge build up. Also like I said in the thread I opened my valve cover to change the gasket and found a ton of sludge.

How is looking through the oil filter a false negative when I clearly stated when I drained it after it was pitch black? Also "looking through holes" doesn't show anything. If you want to see real sludge take your valve cover or oil pan completely off.

LOL. I'm not looking to fight about this, but looking though holes does help indicate if the engine has sludge. If the valve train is sludged up it's not going to hide away from where you can see cylinders 1 and 2 valves. I've pulled the VANOS solenoids 4 times now and none of the small orifices had any sludge. The hole in the oil pan where the oil sensor mounts is about 2" in diameter, so when the car is on a lift you can easily look in and see most of the crankshaft. I found no evidence of sludge anywhere. 2nd pic is my N52 at 131,152 miles (January 12, 2011) after jut 8 oil changes (you can do the math). 3rd pic is through the oil sensor hole in the pan in August 2013 at 225,000 miles (14 oil changes).

An oil filter will look dark brown 5 minutes after oil is run through it, so the color of it indicates nothing.

Further, I have a 1997 Z3 with the M44. I just replaced the timing chain case and valve cover gaskets, along with the OFHG (it's different than the profile gasket the N52/54 uses). I had the entire valve train exposed from the crankshaft all the way back to the rear of the head and the oil filter housing completely off. The engine is 18 years old with 170,000 miles, sees oil changes in accordance with BMW's OCI, which for the M44 from 1997 is about 9,000 to 11,000 miles (my wife drives this car, so it gets oil chnages about every 18 months or so). The car sits quite a bit in the colder months. In the late 90's synthetic wasn't even called for, so the engine used non-synthetic for years. Since 2003 or so I've been using synthetic in it. In 2006/7 I switched to BMW's oil for it. The engine didn't have a spec of sludge anywhere. Here's a pic for you viewing pleasure...

[NoPwrOvrMe]

Originally Posted by Efthreeoh

LOL. I'm not looking to fight about this, but looking though holes does help indicate if the engine has sludge. If the valve train is sludged up it's not going to hide away from where you can see cylinders 1 and 2 valves. I've pulled the VANOS solenoids 4 times now and none of the small orifices had any sludge. The hole in the oil pan where the oil sensor mounts is about 2" in diameter, so when the car is on a lift you can easily look in and see most of the crankshaft. I found no evidence of sludge anywhere. 2nd pic is my N52 at 131,152 miles (January 12, 2011) after jut 8 oil changes (you can do the math). 3rd pic is through the oil sensor hole in the pan in August 2013 at 225,000 miles (14 oil changes).

An oil filter will look dark brown 5 minutes after oil is run through it, so the color of it indicates nothing.

Further, I have a 1997 Z3 with the M44. I just replaced the timing chain case and valve cover gaskets, along with the OFHG (it's different than the profile gasket the N52/54 uses). I had the entire valve train exposed from the crankshaft all the way back to the rear of the head and the oil filter housing completely off. The engine is 18 years old with 170,000 miles, sees oil changes in accordance with BMW's OCI, which for the M44 from 1997 is about 9,000 to 11,000 miles (my wife drives this car, so it gets oil chnages about every 18 months or so). The car sits quite a bit in the colder months. In the late 90's synthetic wasn't even called for, so the engine used non-synthetic for years. Since 2003 or so I've been using synthetic in it. In 2006/7 I switched to BMW's oil for it. The engine didn't have a spec of sludge anywhere. Here's a pic for you viewing pleasure...

Looking through the oil sensor whole maybe. But not the oil fil cap. You can't see everywhere to indicate anything, sludge could be slowly building up behind the scenes... And again you don't seem to understand the part where I said in the other post on this thread that after cleaning out the sludge with diesel the oil filter look clear and gold for thousands of miles. And now when I look at it, it is dark brown and when another engine flush is ran it drains pitch black. So yes looking at the oil filter is a good indicator.

If yours is already black after 5 mins, drain a little and let's see the rest. Dark oil is dirty oil...

Maybe you got lucky because around here in California bmws are notorious for sludge build up no matter the oil change interval. Maybe because we drive a lot.

[Efthreeoh]

Originally Posted by NoPwrOvrMe

Looking through the oil sensor whole maybe. But not the oil fil cap. You can't see everywhere to indicate anything, sludge could be slowly building up behind the scenes... And again you don't seem to understand the part where I said in the other post on this thread that after cleaning out the sludge with diesel the oil filter look clear and gold for thousands of miles. And now when I look at it, it is dark brown and when another engine flush is ran it drains pitch black. So yes looking at the oil filter is a good indicator.

If yours is already black after 5 mins, drain a little and let's see the rest. Dark oil is dirty oil...

Maybe you got lucky because around here in California bmws are notorious for sludge build up no matter the oil change interval. Maybe because we drive a lot.

Sludge build up comes from short duration drives, not "driving a lot". I drive 160 miles a day minimum. My car sees 35+ miles of heavy stop and go traffic every day. My car has 291,500 miles on the original engine on just 20 oil changes. It doesn't have sludge in it. The pic I posted was at 135,000 miles I'll take one this weekend at 180,000 miles later. But having just added a liter (after 6,000 miles) just a week or two ago, I can assure you the pic will look the same. It's not like cylinders 6, 5, 4, 2 and 1, which are not able to be seen through the fill hole, will have sludge around them but somehow cylinder 3 won't; sludge is not like cockroaches that scatter when the light comes on.

[NoPwrOvrMe]

Originally Posted by Efthreeoh

Sludge build up comes from short duration drives, not "driving a lot". I drive 160 miles a day minimum. My car sees 35+ miles of heavy stop and go traffic every day. My car has 291,500 miles on the original engine on just 20 oil changes. It doesn't have sludge in it. The pic I posted was at 135,000 miles I'll take one this weekend at 180,000 miles later. But having just added a liter (after 6,000 miles) just a week or two ago, I can assure you the pic will look the same. It's not like cylinders 6, 5, 4, 2 and 1, which are not able to be seen through the fill hole, will have sludge around them but somehow cylinder 3 won't; sludge is not like cockroaches that scatter when the light comes on.

Sludge is not just caused by short drives -___-. It's also caused my the lack of consistent oil changes, low pressure and running on low/minimum oil. And no shit sludge doesn't scatter like cockroaches. And again like I said maybe you are one of the lucky few with high mileage and NO sludge.

[Efthreeoh]

Originally Posted by NoPwrOvrMe

Sludge is not just caused by short drives -___-. It's also caused my the lack of consistent oil changes, low pressure and running on low/minimum oil. And no shit sludge doesn't scatter like cockroaches. And again like I said maybe you are one of the lucky few with high mileage and NO sludge.

Yeah, well, I've run 3 BMWs (2 past 250,000 miles) with BMW's CBS OCI schedule, the third is at 170,000. So I'm pretty f'ing sure it's not luck my friend. 3K and 5K oil changes are a waste of money.

Peace.

[fazman]

Originally Posted by Efthreeoh

Yeah, well, I've run 3 BMWs (2 past 250,000 miles) with BMW's CBS OCI schedule, the third is at 170,000. So I'm pretty f'ing sure it's not luck my friend. 3K and 5K oil changes are a waste of money.

Peace.

I still feel you are more of a hardcore car guy who can DIY better than most of the people on this site. For the rest of the people, its still cheap insurance to do more frequent fluid/filter changes. While it is a waste of money, i have not heard of anyone saying they changed the fluid early and broke the car??

[Efthreeoh]

Originally Posted by fazman

I still feel you are more of a hardcore car guy who can DIY better than most of the people on this site. For the rest of the people, its still cheap insurance to do more frequent fluid/filter changes. While it is a waste of money, i have not heard of anyone saying they changed the fluid early and broke the car??

None of what you said makes sense. If a person can't DIY, it would make sense to follow the recommended maintenance schedule rather than double it. I think it's fair to say that I've proven the BMW condition-based maintenance system is completely adequate to maintain a BMW through the owner's life with the car.

I have a lift in my garage, I could change any fluid on the car any time I want, but it's a waste of money. By following the CBS maintenance schedule for engine oil on the E90 alone (vs. a 7,500 mile interval) I paid back the cost of the lift.

I can post pics of the valve train on the N52 and the bottom of the block with the oil pan removed when I changed both the OPG and VCG in 2015/2016 at 293,000 and 300,000 miles respectively if you're interested. Not a drop of sludge.

[mweisdorfer]

Originally Posted by Efthreeoh

None of what you said makes sense. If a person can't DIY, it would make sense to follow the recommended maintenance schedule rather than double it. I think it's fair to say that I've proven the BMW condition-based maintenance system is completely adequate to maintain a BMW through the owner's life with the car.

I have a lift in my garage, I could change any fluid on the car any time I want, but it's a waste of money. By following the CBS maintenance schedule for engine oil on the E90 alone (vs. a 7,500 mile interval) I paid back the cost of the lift.

I can post pics of the valve train on the N52 and the bottom of the block with the oil pan removed when I changed both the OPG and VCG in 2015/2016 at 293,000 and 300,000 miles respectively if you're interested. Not a drop of sludge.

If one is concerned about sludge and more oil burn due to the heat of the N54, they should change out the filter 1/2 way through the oil change interval. They could also use an oil flush. Liquid Moly makes a great oil flush. Just use a great quality oil that is LL-01 approved. If you skimp on the quality oil to save a few $$, then you deserve the oil sludge in the car.

I agree, 3,000 or even 5,000 mile intervals are absurd and a waste of money if you just DD the car. Even with an N54.

I have an 07 N54 with 147,000 miles on it. Original injectors and original turbos. I use Amsoil Euro Classic Blend 5w-40 and a Mann Filter every 7500 miles. The Amsoil is good for 15,000 miles. I always use an oil flush before I change the oil, and I always use Techron 20 gallon formula every 6 months. I also always use 93 octane.

Take precautions like above not doing a $40.00 oil change every 3,000 miles. That's silly.

[fazman]

Originally Posted by Efthreeoh

None of what you said makes sense. If a person can't DIY, it would make sense to follow the recommended maintenance schedule rather than double it. I think it's fair to say that I've proven the BMW condition-based maintenance system is completely adequate to maintain a BMW through the owner's life with the car.

I have a lift in my garage, I could change any fluid on the car any time I want, but it's a waste of money. By following the CBS maintenance schedule for engine oil on the E90 alone (vs. a 7,500 mile interval) I paid back the cost of the lift.

I can post pics of the valve train on the N52 and the bottom of the block with the oil pan removed when I changed both the OPG and VCG in 2015/2016 at 293,000 and 300,000 miles respectively if you're interested. Not a drop of sludge.

I believe you have proven these things are very solid and are a serious pioneer in mileage on this platform. But maybe it just gives me the warm fuzzies to keep fresher fluids in the vehicle as I have always done on my japanese rides to high mileage.

[Meeni]

I have had no problems with sludge on OCI intervals. The only time I had sludge problems was when my water pump crapped out.

[bvanlieu]

Just the word sludge conjures up images of wax and tar: handy for the marketing machines and service managers to get additional revenue

Except for some design defect engines that had overly long OCI's on basic oil (remember LL01 is a longer life synthetic with stronger add packs), or a car run 30-50K on the same oil, you are not likely to have any real sludge.

I have no issues running 7-8qt of good synthetic in these cars for the OCI BMW specifies just as Efthreeoh done. I do it for both of our BMWs (that are also turbo charged and not abused).

If you want to do it more often for your own peace of mind, that's perfectly OK but don't think that you need to do that, or it prevents sludge. Nope

- b

[Adieu]

DOUBLE OIL CHANGE (aka oil flush)


Intermediate flush oil can be woth just about anything, keep close in weight and type but use whatever is on sale at walmart (or wallys own supertech synthetic) and dont bother with any of that BMW Longlife nonsense.


Use a new filter for each fill.