[Cruiser124]

Looking for fellow enthusiasts advice on this 335xi that I have the opportunity to purchase. I've owned and serviced many audis over the past few years, but have only owned one bmw. It was an e90 330xi, so I have limited knowledge with bmw in general and the common issues found on the n54.

The problem is it leaks a major amount of oil. I have not looked the car over yet, but after talking with the seller it appears to be losing a quart in 50 miles or so. His mechanics assessment was a bad oil pan gasket. To me it seems possible, but not very likely due to the amount it's losing. He says you can see it dripping towards the rear of the motor when the engine is idling. My thoughts are rear main seal, and this is probably worst case scenario. Drop the transmission and replace the 50$ seal.

What I find myself questioning is the fact that 50 miles prior to losing oil the valve cover gasket was replaced, and prior to this it sounds as if the car never had issues holding oil. So, could the valve cover really dump that much oil??

anyways, the car has 130k and is very clean with sports package and winter package. Black on black. Everything works, and the only issue is the oil leak. Two sets of run flat tires and I'm looking to pay 5k. Seems like a fair price to me assuming the oil leak truly is the only issue. Thoughts???

[tcphoto]

I think that the price of a PPI would be wisely spent.

[jeddo45]

Take a look on the bottom. The oil pan gasket isn't far fetched. When mine went bad, I lost a whole quart in 100 miles so if it's bad enough, it could be. It could also be other areas. VCG, OFHG too.

Check the turbo snails too. You could see them once you remove the underlining. If there's oil leaking past the seals, you'll see it as well.

I think TCPHOTO gives good advice: get a PPI from a mechanic that is familiar with the platform and go from there.

[mweisdorfer]

Originally Posted by Cruiser124

Looking for fellow enthusiasts advice on this 335xi that I have the opportunity to purchase. I've owned and serviced many audis over the past few years, but have only owned one bmw. It was an e90 330xi, so I have limited knowledge with bmw in general and the common issues found on the n54.

The problem is it leaks a major amount of oil. I have not looked the car over yet, but after talking with the seller it appears to be losing a quart in 50 miles or so. His mechanics assessment was a bad oil pan gasket. To me it seems possible, but not very likely due to the amount it's losing. He says you can see it dripping towards the rear of the motor when the engine is idling. My thoughts are rear main seal, and this is probably worst case scenario. Drop the transmission and replace the 50$ seal.

What I find myself questioning is the fact that 50 miles prior to losing oil the valve cover gasket was replaced, and prior to this it sounds as if the car never had issues holding oil. So, could the valve cover really dump that much oil??

anyways, the car has 130k and is very clean with sports package and winter package. Black on black. Everything works, and the only issue is the oil leak. Two sets of run flat tires and I'm looking to pay 5k. Seems like a fair price to me assuming the oil leak truly is the only issue. Thoughts???

The DIY for the rear main seal on an N54/55 or e90 for that matter has never been created anywhere in the net, much less this forum. There is a DIY on YouTube for an e46 for the rear main seal, which might be useful.

My humble suggestion would be to replace both the Rear Main Seal & the Oil Pan Gasket while you are in there.

Three Side Projects, "while you are in there" would be :

1) new o2 sensors
2) 335is engine mounts
3) new trans mounts

A 4th possible "while you are in there" would be to quiet any waste-gate noise. The front turbo is extremely accessible with the subframe & engine fan out of the car.

You could create a DIY, for the rear main seal, and post it to this forum. You would be a "rock star" overnight!!!!

130k - yep both the Rear Main & the Oil Pan Gasket are bad or soon will be !

I'd ask when the water pump was last changed and suspension (shocks & struts + surrounding hardware); the car is at the age where you will want to start replacing control arms (front & rear), bushings in the rear, subframe bushings, & differential bushings.

[Cruiser124]

Originally Posted by mweisdorfer

The DIY for the rear main seal on an N54/55 or e90 for that matter has never been created anywhere in the net, much less this forum. There is a DIY on YouTube for an e46 for the rear main seal, which might be useful.

My humble suggestion would be to replace both the Rear Main Seal & the Oil Pan Gasket while you are in there.

Three Side Projects, "while you are in there" would be :

1) new o2 sensors
2) 335is engine mounts
3) new trans mounts

A 4th possible "while you are in there" would be to quiet any waste-gate noise. The front turbo is extremely accessible with the subframe & engine fan out of the car.

You could create a DIY, for the rear main seal, and post it to this forum. You would be a "rock star" overnight!!!!

130k - yep both the Rear Main & the Oil Pan Gasket are bad or soon will be !

I'd ask when the water pump was last changed and suspension (shocks & struts + surrounding hardware); the car is at the age where you will want to start replacing control arms (front & rear), bushings in the rear, subframe bushings, & differential bushings.

Originally Posted by mweisdorfer

The DIY for the rear main seal on an N54/55 or e90 for that matter has never been created anywhere in the net, much less this forum. There is a DIY on YouTube for an e46 for the rear main seal, which might be useful.

My humble suggestion would be to replace both the Rear Main Seal & the Oil Pan Gasket while you are in there.

Three Side Projects, "while you are in there" would be :

1) new o2 sensors
2) 335is engine mounts
3) new trans mounts

A 4th possible "while you are in there" would be to quiet any waste-gate noise. The front turbo is extremely accessible with the subframe & engine fan out of the car.

You could create a DIY, for the rear main seal, and post it to this forum. You would be a "rock star" overnight!!!!

130k - yep both the Rear Main & the Oil Pan Gasket are bad or soon will be !

I'd ask when the water pump was last changed and suspension (shocks & struts + surrounding hardware); the car is at the age where you will want to start replacing control arms (front & rear), bushings in the rear, subframe bushings, & differential bushings.

I did notice no diy for the e90 on the rear main! I'm a hardcore Audi enthusiast and I've worked on a variety of engines from the 1.8t, 2.0 3.0, 4.2 s4, doing head jobs, turbos, clutches, engine swaps, timing chains, pretty much anything engine related so I know I have the capabilities, and general knowhow to fix the bmw.

Your suggestions definitely seem right on with my thinking (I've been on research overload since coming across this car) 😊
I'm planning to go look at it on Saturday where I will be jacking the car up, removing splash shield and trying to make an accurate assessment on the spot. I know others have suggestions a PPI, which I do agree would be nice, but being mechanically inclined I'll have a good idea what I'm looking at. Planning to theoughouly clean the underside of the engine and let it run on jack stands to hopefully pinpoint the leak.

I will definitely take a look at engine and trans mounts while I'm under there, as well as the turbos.

Do pretty much all n54s have some wastegate rattle? I know the 2.0t audis I've owned have all made noise. Never been a performance problem though

The way I see it it will most likely be a gasket.. (oil pan, rear main, ofhg, vcg,??) being that I can do the labor which is the main cost when replacing these gaskets it would be a relatively "cheap" fix.

Secondly most likely.. turbos? Much more expensive parts wise? Replace both I suppose?

I do know there is no record on water pump. It's Electric, so how often do you guys replace, every 80-100k? Parts seems to be 200-400$?

No record on control arms or suspension so I assume stock. I'm sure the bushing are worn as you said.

At 5k seems like a good deal, I cant possibly imagine spending more than 3k on parts and 8k seems to be a realistic value when fixed, if not more.

I've done a lot of significant projects that would have been worth documenting on the Audi forums. If I end up with this car, it very well could be my opportunity to Contribute 😁

[mweisdorfer]

Originally Posted by Cruiser124

I did notice no diy for the e90 on the rear main! I'm a hardcore Audi enthusiast and I've worked on a variety of engines from the 1.8t, 2.0 3.0, 4.2 s4, doing head jobs, turbos, clutches, engine swaps, timing chains, pretty much anything engine related so I know I have the capabilities, and general knowhow to fix the bmw.

Your suggestions definitely seem right on with my thinking (I've been on research overload since coming across this car) 😊
I'm planning to go look at it on Saturday where I will be jacking the car up, removing splash shield and trying to make an accurate assessment on the spot. I know others have suggestions a PPI, which I do agree would be nice, but being mechanically inclined I'll have a good idea what I'm looking at. Planning to theoughouly clean the underside of the engine and let it run on jack stands to hopefully pinpoint the leak.

I will definitely take a look at engine and trans mounts while I'm under there, as well as the turbos.

Do pretty much all n54s have some wastegate rattle? I know the 2.0t audis I've owned have all made noise. Never been a performance problem though

The way I see it it will most likely be a gasket.. (oil pan, rear main, ofhg, vcg,??) being that I can do the labor which is the main cost when replacing these gaskets it would be a relatively "cheap" fix.

Secondly most likely.. turbos? Much more expensive parts wise? Replace both I suppose?

I do know there is no record on water pump. It's Electric, so how often do you guys replace, every 80-100k? Parts seems to be 200-400$?

No record on control arms or suspension so I assume stock. I'm sure the bushing are worn as you said.

At 5k seems like a good deal, I cant possibly imagine spending more than 3k on parts and 8k seems to be a realistic value when fixed, if not more.

I've done a lot of significant projects that would have been worth documenting on the Audi forums. If I end up with this car, it very well could be my opportunity to Contribute 😁

Wastegate rattle is extremely common and "inevitable" for the N54. Mitsubishi makes the turbos, and I don't think they have beefed up the waste-gate parts to my knowledge. Therefore, if you buy stock, you'd have to buy an after mkt kit for the waste-gates and install it or have it installed prior to replacing the turbos. Welding is part of the procedue when putting better waste-gates on.

VCG - you said was replaced. So, it should be good for at least 45k if not 90k or so.

OFHG - has probably been done, if the car has 130k. They go around 80-90k.

Water pump - 90% of them go between 75 -100k.

Yes, you'd replace the turbos in pairs.

If looking at after market turbos, start with Rob Beck first. He was the pioneer of the first set of after market turbos for the N54. RB 1's & RB 2's are tailored to the DD. All his other stuff is for tracking. He has been known to cut you a deal, if you pay with a cashiers check vs CC.

Most if not all after market turbos allow you to upgrade the waste-gates for an additional fee of about $250-300.00 with some sort of SS Beefed up version.

I'd attempt fix the waste-gates first though. If it stops rattling like mine did, after doing the DIY's, why spend $2,000.00 right now, if you don't have too. Update the vacuum lines with Platinum Cured ones. You can buy it by the foot. You only need 20' max.

You will find that the oil pan & rear main seal butt up to each other, which makes it really difficult to know 100% for sure if it's one or the other.

If you do the Rear Main Seal, I look forward to seeing your DIY....... pictures & all

[Cruiser124]

Originally Posted by mweisdorfer

Wastegate rattle is extremely common and "inevitable" for the N54. Mitsubishi makes the turbos, and I don't think they have beefed up the waste-gate parts to my knowledge. Therefore, if you buy stock, you'd have to buy an after mkt kit for the waste-gates and install it or have it installed prior to replacing the turbos. Welding is part of the procedue when putting better waste-gates on.

VCG - you said was replaced. So, it should be good for at least 45k if not 90k or so.

OFHG - has probably been done, if the car has 130k. They go around 80-90k.

Water pump - 90% of them go between 75 -100k.

Yes, you'd replace the turbos in pairs.

If looking at after market turbos, start with Rob Beck first. He was the pioneer of the first set of after market turbos for the N54. RB 1's & RB 2's are tailored to the DD. All his other stuff is for tracking. He has been known to cut you a deal, if you pay with a cashiers check vs CC.

Most if not all after market turbos allow you to upgrade the waste-gates for an additional fee of about $250-300.00 with some sort of SS Beefed up version.

I'd attempt fix the waste-gates first though. If it stops rattling like mine did, after doing the DIY's, why spend $2,000.00 right now, if you don't have too. Update the vacuum lines with Platinum Cured ones. You can buy it by the foot. You only need 20' max.

You will find that the oil pan & rear main seal butt up to each other, which makes it really difficult to know 100% for sure if it's one or the other.

If you do the Rear Main Seal, I look forward to seeing your DIY....... pictures & all

Very interesting, and greatly appreciated information. As of now I do not know the extent of wastegate rattle, but I would definitely attempt the diy first before buying new turbos. And honestly if the only issue is a little noise I'd probably just live with it.

I know what you're referring to on the oil pan. Seems similar to the 4 cylinder Audi engines where some of the fasteners are located inside the bell housing, so if it leaks there it can be misleading. But Both rear main and oil pan seem like a major pain. Subframe, axles, steering rack, etc need removal for oil pan and transmission and a few other things for rear main I suppose lol

Unfortunately. I don't have the luxury of doing this work on a lift, but I've made me some good old fashion cribbing blocks out of 2x4 to support the car. Worked fine for dropping the trans on my b7 S4.

The idea of a diy certainly sounds nice, and I definitely give credit to those who have taken the time to put one together. All I can say is don't hold your breath.. lol maybe I'll get lucky and that won't even be the issue 🤔

[Cruiser124]

Originally Posted by jeddo45

Take a look on the bottom. The oil pan gasket isn't far fetched. When mine went bad, I lost a whole quart in 100 miles so if it's bad enough, it could be. It could also be other areas. VCG, OFHG too.

Check the turbo snails too. You could see them once you remove the underlining. If there's oil leaking past the seals, you'll see it as well.

I think TCPHOTO gives good advice: get a PPI from a mechanic that is familiar with the platform and go from there.

Interesting to know that your oil pan gasket leaked at a similar rate. I have a good mechanical backround (specifically working on audis) and I plan to jack the car up and do a visual inspection underneath. I'll have a good idea what I'm looking at, more so curious about anything specific, but seems the common gaskets to fail are indeed rear main, oil pan, ofhg, and vc. Whichever it may be I'll fix myself, I'd just prefer not having to get into oil pan or rear main without a lift :/ But if the price is right..

At what mileage did your oil pan gasket go? Was it a slow progressive leak, or did it decide to fail all at once?

[mweisdorfer]

Originally Posted by Cruiser124

Very interesting, and greatly appreciated information. As of now I do not know the extent of wastegate rattle, but I would definitely attempt the diy first before buying new turbos. And honestly if the only issue is a little noise I'd probably just live with it.

I know what you're referring to on the oil pan. Seems similar to the 4 cylinder Audi engines where some of the fasteners are located inside the bell housing, so if it leaks there it can be misleading. But Both rear main and oil pan seem like a major pain. Subframe, axles, steering rack, etc need removal for oil pan and transmission and a few other things for rear main I suppose lol

Unfortunately. I don't have the luxury of doing this work on a lift, but I've made me some good old fashion cribbing blocks out of 2x4 to support the car. Worked fine for dropping the trans on my b7 S4.

The idea of a diy certainly sounds nice, and I definitely give credit to those who have taken the time to put one together. All I can say is don't hold your breath.. lol maybe I'll get lucky and that won't even be the issue 🤔

You could buy a transmission lift for about $100.00 at Harbor Freight. I have one; it lifts 450#. Works awesome.

The DIY's to quite the turbos on the n54 are really quite easy and can be done without taking too much off the top portion of the engine. You are going to be doing major surgery. I know. I've done it. So. When the subframe is removed etc., turning the actuator bolt 2.5x on the rear turbo and putting a double, 8mm horseshoe shaped washer between the actuator housing & the turbo, on the front turbo, will be a piece of cake.

The oil pan is probably 8-10 hours. Not hard, just time consuming. Lots of bolts etc. you will need and engine support bar. 2 point 1000# will work. You'll have to take the tow hook found in the trunk and grind it down a little so it will screw all the way into the screw hole on the top part of the head near the oil filter housing gasket.

Once you have the oil pan out of the car, it's probably 2-3 more hours for the rear main seal. You can probably clean out the torque converter of all the crappy, old ATF. Nothing like having 100% clean ATF.

The sealant for the rear main is made by BMW and it was updated a few years back. That's a dealer item. FYI......

[Cruiser124]

Originally Posted by mweisdorfer

You could buy a transmission lift for about $100.00 at Harbor Freight. I have one; it lifts 450#. Works awesome.

The DIY's to quite the turbos on the n54 are really quite easy and can be done without taking too much off the top portion of the engine. You are going to be doing major surgery. I know. I've done it. So. When the subframe is removed etc., turning the actuator bolt 2.5x on the rear turbo and putting a double, 8mm horseshoe shaped washer between the actuator housing & the turbo, on the front turbo, will be a piece of cake.

The oil pan is probably 8-10 hours. Not hard, just time consuming. Lots of bolts etc. you will need and engine support bar. 2 point 1000# will work. You'll have to take the tow hook found in the trunk and grind it down a little so it will screw all the way into the screw hole on the top part of the head near the oil filter housing gasket.

Once you have the oil pan out of the car, it's probably 2-3 more hours for the rear main seal. You can probably clean out the torque converter of all the crappy, old ATF. Nothing like having 100% clean ATF.

The sealant for the rear main is made by BMW and it was updated a few years back. That's a dealer item. FYI......

Good to know! I'll be checking out the diy here soon. What you describe sounds like basically just adding a washer to the actuator arm to reduce excessive play? I'm also thinking about pulling the intake manifold to do a carbon clean on the intake .

I do have the harbor freight trans jack, engine support, and engine hoist. I've done quite a few trans engine replacements. Also just got the Milwaukee mid torque 1/2 impact that I'm excited to put to use

I know audi says "lifetime" fluid on atf and maybe bmw is the same.. But obviously fluid will break down and become contaminated over time. Whats the general concensus on trans fluid/ filter replacement interval for bmw?

Is the special sealant just some over priced rtv? Lol.

[mweisdorfer]

Originally Posted by Cruiser124

Good to know! I'll be checking out the diy here soon. What you describe sounds like basically just adding a washer to the actuator arm to reduce excessive play? I'm also thinking about pulling the intake manifold to do a carbon clean on the intake .

I do have the harbor freight trans jack, engine support, and engine hoist. I've done quite a few trans engine replacements. Also just got the Milwaukee mid torque 1/2 impact that I'm excited to put to use

I know audi says "lifetime" fluid on atf and maybe bmw is the same.. But obviously fluid will break down and become contaminated over time. Whats the general concensus on trans fluid/ filter replacement interval for bmw?

Is the special sealant just some over priced rtv? Lol.

Lifetime fluid = 100k in BMW's.

Redline, Amsoil, Royal Purple all make great after market substitutes.

I prefer Amsoil. I have a membership and I get 25% off all their products. You can get them in 1 year increments. I bought mine for 5 years.

[jeddo45]

Originally Posted by Cruiser124

Interesting to know that your oil pan gasket leaked at a similar rate. I have a good mechanical backround (specifically working on audis) and I plan to jack the car up and do a visual inspection underneath. I'll have a good idea what I'm looking at, more so curious about anything specific, but seems the common gaskets to fail are indeed rear main, oil pan, ofhg, and vc. Whichever it may be I'll fix myself, I'd just prefer not having to get into oil pan or rear main without a lift :/ But if the price is right..

At what mileage did your oil pan gasket go? Was it a slow progressive leak, or did it decide to fail all at once?

Mine went at about 82k. But I've heard it could go out sooner or even hold till around 100k.

When mine went, it just went, and it was an utter mess.

[Cruiser124]

Originally Posted by jeddo45

Mine went at about 82k. But I've heard it could go out sooner or even hold till around 100k.

When mine went, it just went, and it was an utter mess.

Good to know, thank you! I have Arrangements to pick the car up Friday. Here are a couple pics in the meantime

[jeddo45]

Love your carbon fiber interior accents. I just bought vinyl to do the trims. Looks good!

[Efthreeoh]

There is no F'ing way an oil pan gasket is leaking 1 quart of oil every 50 miles. I'd check the front crank seal. The engine probably ate the serpentine belt and trashed the front crank seal. That car should be a F'ing mess underneath and reek of engine oil. That or it's sucking oil from the sump through the intake.

[Cruiser124]

Originally Posted by Efthreeoh

There is no F'ing way an oil pan gasket is leaking 1 quart of oil every 50 miles. I'd check the front crank seal. The engine probably ate the serpentine belt and trashed the front crank seal. That car should be a F'ing mess underneath and reek of engine oil. That or it's sucking oil from the sump through the intake.

I do agree oil pan seems unlikely, but it could be possible. I've been reading about the horror stories of the belt breaking, but it doesn't sound like that's happened to this car... I'm told it's leaking at the rear of engine. I've yet to see it, but I'm expecting to replace rear main as "worst case"

The leak looks something like this

[CTinline-six]

Originally Posted by jeddo45

Take a look on the bottom. The oil pan gasket isn't far fetched. When mine went bad, I lost a whole quart in 100 miles so if it's bad enough, it could be. It could also be other areas. VCG, OFHG too.

Check the turbo snails too. You could see them once you remove the underlining. If there's oil leaking past the seals, you'll see it as well.

I think TCPHOTO gives good advice: get a PPI from a mechanic that is familiar with the platform and go from there.

What??

That sounds like something other than just the pan gasket. Even if you somehow blew out part of the seal on the pan, I'm not sure if you could leak out that much oil in 100 miles. Oil pans usually seep or have a slow drip, unless someone installed a gasket horribly wrong.

[jeddo45]

Originally Posted by CTinline-six

What??

That sounds like something other than just the pan gasket. Even if you somehow blew out part of the seal on the pan, I'm not sure if you could leak out that much oil in 100 miles. Oil pans usually seep or have a slow drip, unless someone installed a gasket horribly wrong.

Nope. It can assure you it was the oil pan gasket. Once it was fixed, and currently, no oil leaks.

I'm telling you it was bad.

[Efthreeoh]

Originally Posted by Cruiser124

I do agree oil pan seems unlikely, but it could be possible. I've been reading about the horror stories of the belt breaking, but it doesn't sound like that's happened to this car... I'm told it's leaking at the rear of engine. I've yet to see it, but I'm expecting to replace rear main as "worst case"

The leak looks something like this

That video is of a really bad, totally blown rear crank seal and not an oil pan leak. You need special tools and adhesive/sealer to remove and replace the crank seals on the N52/54. I could never find them on linw when I did my clutch and flywheel. Someone did IIRC; what thread it was, I have know idea. I hope that's all it turns out to be. I'd verify that first before I'd even touch that car.

My 2 cents.

[Cruiser124]

Originally Posted by Efthreeoh

That video is of a really bad, totally blown rear crank seal and not an oil pan leak. You need special tools and adhesive/sealer to remove and replace the crank seals on the N52/54. I could never find them on linw when I did my clutch and flywheel. Someone did IIRC; what thread it was, I have know idea. I hope that's all it turns out to be. I'd verify that first before I'd even touch that car.

My 2 cents.

Thanks for you input! You're correct about the video showing a massive rear main leak. I'll be inspecting the underside of the car, but I do believe the rear main seal is at fault. Otherwise oil pan gasket? Honestly, I'd be content replacing any seal or gasket that doesn't involve dropping the transmission :/ lol

I'm sure the BMW dealership would have the sealant on hand (although it's probably way overpriced.)

As far as the tools go, I came across the front main diy for e90. Listed is a Part number for a seal installer and remover. I assume this should work on the rear?

I'll be looking for a quality workshop manual (preferably free) to reference torque specs and any other special procedures. Suggestions??

[mweisdorfer]

Originally Posted by Cruiser124

Thanks for you input! You're correct about the video showing a massive rear main leak. I'll be inspecting the underside of the car, but I do believe the rear main seal is at fault. Otherwise oil pan gasket? Honestly, I'd be content replacing any seal or gasket that doesn't involve dropping the transmission :/ lol

I'm sure the BMW dealership would have the sealant on hand (although it's probably way overpriced.)

As far as the tools go, I came across the front main diy for e90. Listed is a Part number for a seal installer and remover. I assume this should work on the rear?

I'll be looking for a quality workshop manual (preferably free) to reference torque specs and any other special procedures. Suggestions??

The sealant is about $35.00 at BMW. The tool you can probably buy at ECS tuning - $200.00 or so. Manual - Bentley Repair manual $100.00....

Please post a link to the DIY you found.

[Cruiser124]

Originally Posted by mweisdorfer

The sealant is about $35.00 at BMW. The tool you can probably buy at ECS tuning - $200.00 or so. Manual - Bentley Repair manual $100.00....

Please post a link to the DIY you found.

Thanks!

http://www.e90post.com/forums/showthread.php?t=1299182