[WrenchesOnJunk]

Hello!

About a month ago, I picked up a 200k mile 2006 330i MT for cheap, and am actually considering keeping it and selling the 550i. The previous owner of the E90 had the mindset of "it only needs a quart a month and it runs well, I'll keep driving it." In the quest to make it a better driver, so far, I replaced the valve cover gasket, oil pan gasket, motor/trans mounts, and sway bar links, but it's still got probably one of the worst OFHG leaks ever. This weekend, I'll be tearing it apart to inspect and replace the DISA flaps, replace OFHG, along with contaminated coolant hoses, serpentine belt, tensioner, and idler. Might also flush the brake fluid.

After reading various DIYs, the following is arriving tomorrow:
3 PCV hoses: 11617522933, 11157567801, 11157522931 were the original part #s
Belt, Tensioner, Idler kit
Intake Manifold Gasket - 537890
Intake Manifold Gasket - 524420
Upper Radiator Hose
Lower Radiator Hose
OFHG to Thermostat Hose
DISA Kit Left & Right

Anything I missed, or may as well replace while I have the intake off and cooling system drained? I have a K+DCAN cable on the way as well, so I plan to scan for the top-secret BMW codes to see if it tells me there's anything else I need to replace. Thanks in advance for any suggestions or advice!

[StradaRedlands]

Originally Posted by WrenchesOnJunk

Hello!

About a month ago, I picked up a 200k mile 2006 330i MT for cheap, and am actually considering keeping it and selling the 550i. The previous owner of the E90 had the mindset of "it only needs a quart a month and it runs well, I'll keep driving it." In the quest to make it a better driver, so far, I replaced the valve cover gasket, oil pan gasket, motor/trans mounts, and sway bar links, but it's still got probably one of the worst OFHG leaks ever. This weekend, I'll be tearing it apart to inspect and replace the DISA flaps, replace OFHG, along with contaminated coolant hoses, serpentine belt, tensioner, and idler. Might also flush the brake fluid.

After reading various DIYs, the following is arriving tomorrow:
3 PCV hoses: 11617522933, 11157567801, 11157522931 were the original part #s
Belt, Tensioner, Idler kit
Intake Manifold Gasket - 537890
Intake Manifold Gasket - 524420
Upper Radiator Hose
Lower Radiator Hose
OFHG to Thermostat Hose
DISA Kit Left & Right
Also I have a tiny leak at the radiator neck, and will likely repair that instead of replacing the radiator, and keep an eye on it.

Anything I missed, or may as well replace while I have the intake off and cooling system drained? I have a K+DCAN cable on the way as well, so I plan to scan for the top-secret BMW codes to see if it tells me there's anything else I need to replace. Thanks in advance for any suggestions or advice!

I hope it ends up being a great car for you! I love the 2006 330i cars... literal free horsepower in them!

Yes, do the brakes. Fluid is probably quite old.

OFHG is really easy to replace. Do the Mickey flange while there. I replaced the hose at the same time. I'd say do as many hoses as you can while you're at it. They're all the same age. Especially the hose that goes across the top of the radiator to the expansion tank. The plastic gets brittle and cracks. I'd also just get a new radiator... Nissens are cheap and should be a lot more efficient than the 200k one in there now.

New VANOS seals and clean them while out.

Voltage regulator that goes on the back of the alternator.

You probably already are thinking of it, but the MT and differential fluids. Easy to change and probably needed.

All of the above is sort of inexpensive, but be thinking about water pump/tstat. Maaaybe do preventatively, but they are pricey compared to everything else above. If they're working fine, I'd just let 'em be, but have one speed dial!

Enjoy!

[Phil325i]

I found this video very helpful. One of the few suggested methods for OFHG replacement that involved no loss of coolant and minimal oil loss.

Good luck!

[WrenchesOnJunk]

Originally Posted by StradaRedlands

I hope it ends up being a great car for you! I love the 2006 330i cars... literal free horsepower in them!

Yes, do the brakes. Fluid is probably quite old.

OFHG is really easy to replace. Do the Mickey flange while there. I replaced the hose at the same time. I'd say do as many hoses as you can while you're at it. They're all the same age. Especially the hose that goes across the top of the radiator to the expansion tank. The plastic gets brittle and cracks. I'd also just get a new radiator... Nissens are cheap and should be a lot more efficient than the 200k one in there now.

New VANOS seals and clean them while out.

Voltage regulator that goes on the back of the alternator.

You probably already are thinking of it, but the MT and differential fluids. Easy to change and probably needed.

All of the above is sort of inexpensive, but be thinking about water pump/tstat. Maaaybe do preventatively, but they are pricey compared to everything else above. If they're working fine, I'd just let 'em be, but have one speed dial!

Enjoy!

I'm definitely loving the car so far. Plenty of power for where I live, and I forgot how nimble yet solid they feel in comparison to the big ol' F10. Also had a 2007 335i, but it was auto, and I'd take a manual 330 over an auto 335, honestly. Better gas mileage than both, too!

I still haven't decided how far I want to go with throwing new parts at the car, given its age and value. It wouldn't hurt to drain the coolant twice anyway, so I'll probably take a close look at the other hoses while I'm in there, and replace them along with the radiator down the line. The OFHG to thermostat hose I ordered looks like it comes with the mickey mouse flange, but may switch it to a metal one next time I'm in there.

I've also had my eye on the water pump/thermostat when I've been parts searching, since they're usually something I replace when I get a higher mileage car, but I've opted to just wait till they have a problem because $$$ haha.

Thanks for the suggestions! I figured there'd be a whole next round of repairs in the near future for this one.

[POBEP]

Originally Posted by WrenchesOnJunk

Anything I missed

You can add PS reservoir and fluid replacement.
200K/16Y is about right timing.

Aluminum mickey mouse flange is the only way to go.
OEM version is complete garbage.

[Phil325i]

[QUOTE=Efthreeoh;29138431]I have a 2006 325i, 400,000 mile N52. /QUOTE]

Wow! You must have one of the highest miles N52s on this forum...if not the world! Great to know that these engines have that kind of mileage in them. Are you on original internals?

[hassmaschine]

Sounds like me and my car.... I'm at 170,000 miles, and have basically been like - it runs fine... leave it be and drive it. Don't fix it if it ain't broke. That has served me well over the last 8 years. This car has cost me basically nothing to run and drive other than gas, insurance, and tires.

I've started doing a little bit of preventative maintenance (ordered 6 new coils - OMG! I've replaced one like 6 years ago - the other's haven't failed, I just don't want to worry about it). Thinking of replacing the OE sport shocks too, before they go NLA. The car still rides and handles great on the completely stock and original suspension, but the 2006 330i with sport suspension is such an odd bird, I don't want to wait until I can't get the parts at all.

[WrenchesOnJunk]

Originally Posted by POBEP

You can add PS reservoir and fluid replacement.
200K/16Y is about right timing.

Aluminum mickey mouse flange is the only way to go.
OEM version is complete garbage.

The power steering does have a bit of a whine, so I'm hoping replacing the fluid helps, but noted, will do the reservoir too!

(Also, might have been inspired by your signature haha)

Originally Posted by hassmaschine

Sounds like me and my car.... I'm at 170,000 miles, and have basically been like - it runs fine... leave it be and drive it. Don't fix it if it ain't broke. That has served me well over the last 8 years. This car has cost me basically nothing to run and drive other than gas, insurance, and tires.

I've started doing a little bit of preventative maintenance (ordered 6 new coils - OMG! I've replaced one like 6 years ago - the other's haven't failed, I just don't want to worry about it). Thinking of replacing the OE sport shocks too, before they go NLA. The car still rides and handles great on the completely stock and original suspension, but the 2006 330i with sport suspension is such an odd bird, I don't want to wait until I can't get the parts at all.

Since getting this car, I'm learning how solid the E90/N52 setup is at high mileage; definitely impressed! Hopefully you at least changed the oil too, haha. Also, I'm pretty sure all E90s with the sport suspension share the same part number. Even though they only made the 330i for a year in the US, pretty much all the non-engine parts are shared with all pre-LCI e90s, and a lot of the specific engine parts with the 530 and Z4 30i. Personally, I'm not too worried about parts support with this car so far.


Update on the car: ended up replacing the OFHG, serpentine belt setup, mickey mouse hose, and the upper rad hose. The lower was being a pita and doesn't look too bad, so I decided to save it for when I do the radiator. The heater supply hose (64219178427) is pretty bubbly from oil contamination, so that one's on the way, but so far I haven't noticed any others that worry me. Didn't end up taking the intake off at all, but on inspecting the DISAs, I decided I'll just be ordering new ones to play it safe.

I replaced a couple other parts while the car was down, and took it on a test drive this evening. Found myself expecting the smell of oil burning on the exhaust at certain points, and was so happy when it didn't happen! Snapped a before and after the cleaning that took place as part of this; wasn't going for show-car clean, but it was pretty gnarly.

Thanks again for the input!

[Phil325i]

Worth also checking the rad vent hose - No.7 in this pic:

https://www.realoem.com/bmw/enUS/sho...diagId=17_0350

It's hidden behind the air inlet trumpet and is a known weak point...

[Suvorovo]

I'd add the oil check valves on the passenger side of the engine. They're ~40 each. Easy to access through the wheel well. If your vanos solenoids start to fail, at least youll know it’s not a faulty check valve.

Also, the expansion tank is known to crack. That's also a cheap replacement.

[WrenchesOnJunk]

Originally Posted by Phil325i

Worth also checking the rad vent hose - No.7 in this pic:

https://www.realoem.com/bmw/enUS/sho...diagId=17_0350

It's hidden behind the air inlet trumpet and is a known weak point...

I ended up reading up on the McDonald's Straw coolant line, but hated the idea of replacing it with the same design, and I don't see any plug and play aftermarket options. It snapped during my last group of repairs, and I decided to just cut some of the rubber hose coming from the reservoir off, threw on a hose connector, and some quality rubber hose directly across to the upper rad nipple, and it seems like it'll work well!

Originally Posted by Suvorovo

I'd add the oil check valves on the passenger side of the engine. They're ~40 each. Easy to access through the wheel well. If your vanos solenoids start to fail, at least youll know it’s not a faulty check valve.

Also, the expansion tank is known to crack. That's also a cheap replacement.

I've been seeing these check valves mentioned occasionally. Considering the condition of the rest of the car, I may as well swap in new ones.


Update on the car: Radiator leak got worse pretty quickly, and the lower rad hose also started leaking after I was unsuccessful in removing it, so I ended up doing the radiator, lower rad hose, heater inlet hose (PITA), and both DISAs after work Monday. The old DISAs were both junk; the large flap had disconnected at the end, and was just flopping around from the lower housing area, and the small valve had a little play, but rotated with zero resistance.
I've also driven about 1200 miles since the last oil change, and the oil level seems to be pretty steady! It displayed at full right after the change, but dropped down a tick around the time I did the OFHG, and has been at that level since. I'm hopeful this car might just be a road oiler and not an oil burner!
As of now, I plan to do the VANOS seals at some point, but otherwise, hopefully just going to put some miles on it and see how it does. So far, I have right around $4000 into this car, and averaging 30mpg seems attainable...I'm leaning more and more toward ditching the 550i in favor of this one, every day!

Thanks for the suggestions; happy to field any other recommendations for things to keep on my radar!

[StradaRedlands]

Sooooo clean... just soapy wooder and a brush, or something else?
I need to commit to doing something to clean mine up.

[WrenchesOnJunk]

Originally Posted by StradaRedlands

Sooooo clean... just soapy wooder and a brush, or something else?
I need to commit to doing something to clean mine up.

Mostly just some spray degreaser and careful pressure washing, and minor touchup with microfiber cloths. Oily engines bug me haha

[StradaRedlands]

Originally Posted by WrenchesOnJunk

Mostly just some spray degreaser and careful pressure washing, and minor touchup with microfiber cloths. Oily engines bug me haha

Quite the difference! Tons of oil baked on to the front of mine... I wanted to clean it up, but just wanted to get it put back together as well. Will contemplate the process!

[Suvorovo]

4k sounds about right. I'm in around 3k on my 330xi including having to buy additional tools DIY. Mine was fairly sorted (Receipts show ~5k spent at shops/dealer in the last 4 years), just replacing worn items pre-emptively. Still have to pick up $700 Disas, do oil pan, and eventually clutch then I'm golden.

[TDF9]

Fun to read about your high mileage N52... sounds very familiar: bought my 06 325i 6MT with 200k miles and in need of a clutch job in 2018. Now at 241k miles and running strong, just back from a 10k road trip around the US. Only mechanical issues were the fuel regulator started leaking (and smelling) in utah, and somewhere I managed to crack a rear rim and developed a fast tire leak. Took a water pump with me just in case but so far have not needed it. With the three stage intake upgrade, the car is just so fun to drive. And I saw 30 MPG consistently on the highway as long as I kept it under 75 MPH. Pretty astounding, really, for a car of this age. Have done all the same jobs you describe... OFHG, oil pan, valve cover gasket, radiator, PCV, shocks, starter and had to replace the rear suffrage (rusted through). Anyway, enjoy!

[WrenchesOnJunk]

Originally Posted by Suvorovo

4k sounds about right. I'm in around 3k on my 330xi including having to buy additional tools DIY. Mine was fairly sorted (Receipts show ~5k spent at shops/dealer in the last 4 years), just replacing worn items pre-emptively. Still have to pick up $700 Disas, do oil pan, and eventually clutch then I'm golden.

That's awesome yours was sorted, not the case here though haha. I think mine was a lease, then got picked up by someone who drove it from 40-170k, had an issue and sold it; then a young kid got ahold it, so that's pretty much where I'm at. It had a 225 on the rear right rim, and a 255 (correct size) on the left rear, so a little over $400 of the $4k was to get new rear tires put on ASAP.

Originally Posted by TDF9

Fun to read about your high mileage N52... sounds very familiar: bought my 06 325i 6MT with 200k miles and in need of a clutch job in 2018. Now at 241k miles and running strong, just back from a 10k road trip around the US. Only mechanical issues were the fuel regulator started leaking (and smelling) in utah, and somewhere I managed to crack a rear rim and developed a fast tire leak. Took a water pump with me just in case but so far have not needed it. With the three stage intake upgrade, the car is just so fun to drive. And I saw 30 MPG consistently on the highway as long as I kept it under 75 MPH. Pretty astounding, really, for a car of this age. Have done all the same jobs you describe... OFHG, oil pan, valve cover gasket, radiator, PCV, shocks, starter and had to replace the rear suffrage (rusted through). Anyway, enjoy!

Totally agree - this car impresses me every time I hop into it. Glad to hear yours did alright on a long trip - the farthest I've taken mine, so far, is about 250 miles from home, but I hope to get it to the point where I trust it to drive farther. Sunroof is non-op though, I get an evap CEL every 2 weeks or so, the fob only locks but doesn't unlock, and the adaptive light error comes on 4/5 times I start the car, but mechanically, it's almost there.


So far, since the DISAs and radiator replacement on 8/1, I've put about 2000 miles on it, and the only issue in that time was the rear driver side window regulator. I'm going to try just replacing the plastic carrier clip to the tune of $7 and cross my fingers. Otherwise, the oil level indicator dropped down to the middle, so I'm still losing/using a bit of oil, but given the oil was changed about 3000 miles ago, I'd say it ain't bad for a 200k mile BMW.

[Volasko]

Originally Posted by WrenchesOnJunk

Hello!

About a month ago, I picked up a 200k mile 2006 330i MT for cheap, and am actually considering keeping it and selling the 550i. The previous owner of the E90 had the mindset of "it only needs a quart a month and it runs well, I'll keep driving it." In the quest to make it a better driver, so far, I replaced the valve cover gasket, oil pan gasket, motor/trans mounts, and sway bar links, but it's still got probably one of the worst OFHG leaks ever. This weekend, I'll be tearing it apart to inspect and replace the DISA flaps, replace OFHG, along with contaminated coolant hoses, serpentine belt, tensioner, and idler. Might also flush the brake fluid.

After reading various DIYs, the following is arriving tomorrow:
3 PCV hoses: 11617522933, 11157567801, 11157522931 were the original part #s
Belt, Tensioner, Idler kit
Intake Manifold Gasket - 537890
Intake Manifold Gasket - 524420
Upper Radiator Hose
Lower Radiator Hose
OFHG to Thermostat Hose
DISA Kit Left & Right

Anything I missed, or may as well replace while I have the intake off and cooling system drained? I have a K+DCAN cable on the way as well, so I plan to scan for the top-secret BMW codes to see if it tells me there's anything else I need to replace. Thanks in advance for any suggestions or advice!

Swap the rear diff with one from an AT 330i and you'll find that the engine takes on a whole new feeling. One of the best performance mods you can do for the money. Everything bolts right up, no modifications needed. The 15% extra torque to the wheels really livens up the car and makes it feel so much lighter on its feet. Enjoy the 330i, i've had mine for over 10 years and I still love it as much as I did when I first got it, now mind you it is quite the different beast than it was when I first got it. It has nearly 300k km's and still runs like a champ.

[NorthernDancer]

Originally Posted by WrenchesOnJunk

The power steering does have a bit of a whine, so I'm hoping replacing the fluid helps, but noted, will do the reservoir too!

(Also, might have been inspired by your signature haha)



Since getting this car, I'm learning how solid the E90/N52 setup is at high mileage; definitely impressed! Hopefully you at least changed the oil too, haha. Also, I'm pretty sure all E90s with the sport suspension share the same part number. Even though they only made the 330i for a year in the US, pretty much all the non-engine parts are shared with all pre-LCI e90s, and a lot of the specific engine parts with the 530 and Z4 30i. Personally, I'm not too worried about parts support with this car so far.


Update on the car: ended up replacing the OFHG, serpentine belt setup, mickey mouse hose, and the upper rad hose. The lower was being a pita and doesn't look too bad, so I decided to save it for when I do the radiator. The heater supply hose (64219178427) is pretty bubbly from oil contamination, so that one's on the way, but so far I haven't noticed any others that worry me. Didn't end up taking the intake off at all, but on inspecting the DISAs, I decided I'll just be ordering new ones to play it safe.

I replaced a couple other parts while the car was down, and took it on a test drive this evening. Found myself expecting the smell of oil burning on the exhaust at certain points, and was so happy when it didn't happen! Snapped a before and after the cleaning that took place as part of this; wasn't going for show-car clean, but it was pretty gnarly.

Thanks again for the input!

I'm certain that you know this already and have or will soon replace the serpentine belt. With that much oil leakage, the serpentine belt is a time bomb because of some oil getting onto the belt.

[WrenchesOnJunk]

Originally Posted by Volasko

Swap the rear diff with one from an AT 330i and you'll find that the engine takes on a whole new feeling. One of the best performance mods you can do for the money. Everything bolts right up, no modifications needed. The 15% extra torque to the wheels really livens up the car and makes it feel so much lighter on its feet. Enjoy the 330i, i've had mine for over 10 years and I still love it as much as I did when I first got it, now mind you it is quite the different beast than it was when I first got it. It has nearly 300k km's and still runs like a champ.

Honestly, for the area I live in, I can cruise about 75mph/120kph, but anything over, is fair game for a speeding ticket. This car has plenty of torque and acceleration for anything I've encountered so far. If anything, I'd probably wait until/if the diff gives me problems, and then get something with a higher ratio to space the gears out a bit more, and maybe improve highway mpg. Glad to hear of other high mi/km N52s out there; will see if I keep this long enough to get it from 205k to 300k mi!

Originally Posted by NorthernDancer

I'm certain that you know this already and have or will soon replace the serpentine belt. With that much oil leakage, the serpentine belt is a time bomb because of some oil getting onto the belt.

Yeah - the tensioner was also misaligned, probably just from being worn out, so I got the Continental kit with the tensioner and pulley from rockauto.

[sabino56]

I have same car, about 160k. Bought it with 25k on odometer from first owner and I’ve not had to do much of anything on it except a water pump and the valve cover due to oil leak. Oil pan leak is next when it cools down a bit outside.

I replaced PCV, manifold gasket, and starter when doing the valve cover. Starter just because it was so easy once manifold and pcv were out of the way. No problems with the original starter.

There is a recall on the PCV heater for this car. The original recall fix was to replace the pcv but from what I’ve read it sounds like the new fix is to put a fuse on the pcv heater in-line somewhere. I didn’t know this when I was in there unfortunately or I’d have either put in a fuse or just unplugged the pcv heater as I live in Tucson and almost never gets to freezing where it’s needed. You might want to read up on that recall and decide what to do before getting into the pcv replacement.

[WrenchesOnJunk]

Originally Posted by sabino56

I have same car, about 160k. Bought it with 25k on odometer from first owner and IÂ’ve not had to do much of anything on it except a water pump and the valve cover due to oil leak. Oil pan leak is next when it cools down a bit outside.

I replaced PCV, manifold gasket, and starter when doing the valve cover. Starter just because it was so easy once manifold and pcv were out of the way. No problems with the original starter.

There is a recall on the PCV heater for this car. The original recall fix was to replace the pcv but from what I’ve read it sounds like the new fix is to put a fuse on the pcv heater in-line somewhere. I didn’t know this when I was in there unfortunately or I’d have either put in a fuse or just unplugged the pcv heater as I live in Tucson and almost never gets to freezing where it’s needed. You might want to read up on that recall and decide what to do before getting into the pcv replacement.

Yeah, even the leaky radiator didn't seem likely to explode anytime soon. The car has started and driven awesome every time, so I really can't complain overall. The Takata airbag and blower motor wiring recalls hadn't been done when I bought the car, and those got done about a month ago. Shortly after, I got a call from a dealer about the recall, saying they were scheduling repairs for the PCV recall. I'll definitely go for it when it's convenient; I can usually get a free loaner out of em, and that's always a bonus haha. Still haven't messed with the PCV system otherwise actually.


Otherwise, update: I put the car up on jacks today after work to inspect some more stuff, change the diff fluid, and flush the brake fluid. Surprisingly, on my post-maintenance drive, it seems like a lot of the drivetrain clunkiness when changing gears, has gone away. I wasn't expecting anything noticeable; is it weird that a fluid change would make such a difference?

After the inspection, I have a pretty good list of parts to order, including both guibos, diff bushings, trans fluid, valve cover gasket (again), spark plugs, front forward LCAs, front tires, and a bunch of other miscellaneous stuff. I'm just over $4000 into the car total, but looking like I'll be lucky to be under $5k after this! Really has been an easy car to work on though. I've seen some videos of people working on other Euro cars, and those Audi engines make the E90/N52 platform seem like a walk in the park, in comparison. I'll have to remember that as I wrestle the valve cover for the second time...