[Chark-attack]

Howdy,

I'd be interested to know more about how to properly prolong the life of the N52 and my 06 e90 at large. It seems most everything I read is that the N52 is pretty damn reliable so long as X, Y and Z are addressed but anecdotally it seems like these engines are pretty maintenance heavy and it always feels as if something else is about to go wrong.

I've done a tremendous amount of work to mine since I purchased in December and always feel like the goalposts are being moved on me. Kind of like the whack a mole game with solving issues.

I work as a general tech so I have access to bays, lifts, scan tools, etc. BMW specific specialty tools we dont have an abundance of but we do work on some, primarily older or the recent out of warranty.

Work I have done to mine since January 1st (1500 miles at most that I've owned it)

Valve cover gasket
Oil filter housing gasket
Eccentric shaft sensor and gasket
Eccentric shaft actuator and seal
Starter
Crankshaft position sensor and o-rings
2x camshaft position sensors and seals
2x vanos solenoids and seals
Intake manifold gasket set
Serpentine belt
Belt tensioner
Idler pulley
Spark plugs
Ignition coils
Mass air flow sensor
Power distribution pack (top of battery)
Battery
Fuel pump
Front brake rotors
Front and rear brake pads
Upper radiator hose
Coolant flush
Oil change twice
10 piece front control arm kit (https://www.fcpeuro.com/products/bmw...2-e90caxdrive2)
ECU remanufactured
Transfer case module
2x Hood lift shocks
2x Trunk lift shocks
Brake pad wear sensor
Windshield washer pump
Window regulator

Current primary issues with mine:

1. SES light comes on every time I clear it, codes thrown for vanos. Local german indy said it needs a new ESS. I didnt see oil in the connector, but very rough at initial idle. 30 to 45 seconds or more for it to settle.

2. Slow start, but turns over every time. Replaced fuel pump but didnt solve it. Considering replacing the fuel sending unit next. I have pressure at the rail, but not overnight. Drops to near 0 after 20 minutes, but I attempt to start the vehicle within 5 minutes of shutting it off its pretty hit or miss with how long it cranks.

3. Passenger front door needs an actuator, only unlocks manually via handle.

4. Intermittent water coming inside the vehicle. Have tried cleaning sun drains, resealing sound pad behind the door card on passenger rear door where it is most prevalent. Sometimes it seems it comes in via the drain plugs on the floor, others the door itself. I've already pulled the full carpet interior and keep a towel inside to catch any water.

5. Two open recalls I havent had time to fix via the dealer. No AC but I'm guessing I'm blower motor recall may solve that.

6. Not sure if I have a vacuum leak, havent had a chance to inspect further. Car feels like it is pretty weak and doesnt run how I expect it to.

And a few other smaller issues. I love the car, and would like to hold on to it well past 200k. But it seems overwhelming at times. Current mileage is 112k for what its worth.

Thank you in advance and I appreciate you taking the time to read this.

Cheers,
Will

[ryan stewart]

Water pump is the other risky thing. Also have you changed fluid/filter in tranny?

Otherwise half of that has nothing to do with n52, just wear items depending on use

[Biginboca]

No AC could be the evaporator which is a common failure on these cars. You said you suspected the blower motor recall so I’m guessing that when you turn on the ac no air blows? If so then obviously not the evaporator. If it blows and is warm then is likely the evaporator.

Water in the vehicle can also be from the cowlings and seals at the base of the windshield not being installed properly. If the windshield isn’t OEM then I would say take a look at all those seals under the windshield wiper cowling. There may be a part missing or the strip the windshield wiper cowling locks into may not be installed properly.

Weak crank can be a corroded ground wire or simply an old battery. There’s a ground wire under the motor somewhere that’s a commonly corroded part. A little internet searching should turn up the details.

[Chark-attack]

Originally Posted by ryan stewart

Water pump is the other risky thing. Also have you changed fluid/filter in tranny?

Otherwise half of that has nothing to do with n52, just wear items depending on use

I havent done water pump yet, though I know I need to eventually. I had my upper radiator hose "blow apart" on me a while back. Coolant spilled everywhere and started smoking so I had it towed to the local indy. They replaced the hose and inspected the cooling system, clean bill of health. But needless to say, I know it still needs to be done.

I haven't touched the tranny fluid or filter, but I have a sneaking suspicion that mine is on it's way out. Might be starting to slip but havent dug into it too far yet. Transmissions arent my wheelhouse unfortunately.

And yeah, most of that isnt engine related at all. Just a comprehensive list of stuff I've addressed, meant mostly towards the "e90 at large" comment.

Thanks for the input!

[Chark-attack]

Originally Posted by Biginboca

No AC could be the evaporator which is a common failure on these cars. You said you suspected the blower motor recall so I’m guessing that when you turn on the ac no air blows? If so then obviously not the evaporator. If it blows and is warm then is likely the evaporator.

Water in the vehicle can also be from the cowlings and seals at the base of the windshield not being installed properly. If the windshield isn’t OEM then I would say take a look at all those seals under the windshield wiper cowling. There may be a part missing or the strip the windshield wiper cowling locks into may not be installed properly.

Weak crank can be a corroded ground wire or simply an old battery. There’s a ground wire under the motor somewhere that’s a commonly corroded part. A little internet searching should turn up the details.

No air movement of any kind. The water is primarily, almost exclusively, in the passenger rear footwell. I installed the BMS cowl filters so most of that factory plastic cowling is off the vehicle.

The battery was brand new under warranty, and I have done a load test since installation
I can do another load test this weekend for proper elimination. I inspected the larger engine ground two weeks ago during a transfer case service and all looked relatively normal, but I didnt disconnect and clean the surfaces. I've been considering ordering one just as a precaution but all of these things add up.

Thank you!

[mecheng77]

Put jumper cables between block and chassis and if it's better clean or replace ground strap under the engine

[Bimmer_Engineer]

N52s are notoriously unreliable...have you considered getting an N54? It’s a much better engine...and way more reliable...

[solo118]

Originally Posted by Bimmer_Engineer

N52s are notoriously unreliable...have you considered getting an N54? It’s a much better engine...and way more reliable...

[ctuna]

Diagnostic Manuals Inpa/Ista D
https://bimmerprofs.com/diagnostics-inpa-part-1/
https://www.google.com/url?sa=t&rct=...7x8H3pN8h1fMuF
https://carmod.ru/files/icom/istad_en.pdf
https://www.e90post.com/forums/showthread.php?t=1681573
https://www.bimmerforums.com/forum/s...-P-actually-do
primary links
https://www.bimmerfest.com/forums/at...9&d=1539905743
https://www.e90post.com/forums/showthread.php?t=1681573
https://www.bimmerfest.com/forums/at...1&d=1590283589

N54 all the troubles of an N52 plus expensive turbo troubles.

[Efthreeoh]

Was the car in a flood? Way too many issues for just 112K miles. It was not well taken care of by previous owners. For the VANOS, maybe the drain-back filters are clogged. For the water issue, either the top of the cabin air filter housing is incorrectly installed or the windshield was replaced and incorrectly reinstalled.

[hassmaschine]

Yeah, I was wondering the same thing, lol. CPS and both cam sensors, vanos solenoids and the DME? Why would you need to replace the DME?

[Chark-attack]

Originally Posted by hassmaschine

Yeah, I was wondering the same thing, lol. CPS and both cam sensors, vanos solenoids and the DME? Why would you need to replace the DME?

Quoted you but replying to both above about flooding.

It wasnt specifically in a flood or an area where water submerged the roads. But the previous owner, my brother, had his friends replace a window regulator/motor assembly and i dont think they sealed the vapor barrier back properly. The car was parked on a front down incline, and after prolonged rains there was a significant water accumulation inside in the passenger rear footwell. 2-3 inches of sitting water which sloshed forward and toasted the transfer case module. I'm guessing between that and water also finding it's way into the DME box, slightly, that it fried both the DME and TC modules. Basically, after replacing the eccentric shaft actuator and doing the limit learn, it still wasn't getting power. Probed a bit and pulled the dme to inspect and saw corrosion and other water damage, hence the remanufacture.

[Greyfox]

Originally Posted by Bimmer_Engineer

N52s are notoriously unreliable...have you considered getting an N54? It’s a much better engine...and way more reliable...

You need to be Jethro'd...

[Leucosticte]

I haven't had to replace nearly the amount of stuff you have and I bought my car at 129k, I feel like your car is a lemon or something lol.

[hassmaschine]

He said it got flooded basically. So probably just chasing issues related to that.

[Efthreeoh]

Originally Posted by hassmaschine

He said it got flooded basically. So probably just chasing issues related to that.

Does it make sense that 2 - 3 inches of water in the right rear foot well "sloshing around" would get into the well-sealed DME box under the hood through a grommet in the firewall?

[Chark-attack]

Originally Posted by Efthreeoh

Does itake sense that 2 - 3 inches of water in the right rear foot well "sloshing around" would get into the well-sealed DME box under the hood through a grommet in the firewall?

I dont think the two are related.

[Efthreeoh]

Originally Posted by Chark-attack

I dont think the two are related.

So the DME box was opened at some point? Did you open it during the VCG replacement? I opened my DME box to gain more slack to get the wiring harnesses out of the way.

So when you bought the car from your brother in December 2019, did the car have drivability issues and ECU codes and you've been chasing them ever since? You've replaced everything in the VANOS system other than the drain-back valves, but at the same time replaced the valve cover and ESS, yet you think it needs another new ESS? Nothing is making sense. New plugs and coils too. The only thing I can think of is the VANOS drives on the cams are suffering from the somewhat common broken bolt issue. You had the valve cover off did you check the bolts on the VANOS drives.

So when you say "clean the sun(roof) drains" what does that mean? Just the front drains? Did you clear the rear drains as well? They are hard to get to since they are way in the back of the sunroof cartridge and you'd need a very long piano wire to get down into the drains.

Also, do you know about newtis.info. That website has all the BMW tech info to help test and diagnose the issues the car is having.

Just trying to help.

[Efthreeoh]

Originally Posted by ctuna

Diagnostic Manuals Inpa/Ista D
https://bimmerprofs.com/diagnostics-inpa-part-1/
https://www.google.com/url?sa=t&rct=...7x8H3pN8h1fMuF
https://carmod.ru/files/icom/istad_en.pdf
https://www.e90post.com/forums/showthread.php?t=1681573
https://www.bimmerforums.com/forum/s...-P-actually-do
primary links
https://www.bimmerfest.com/forums/at...9&d=1539905743
https://www.e90post.com/forums/showthread.php?t=1681573
https://www.bimmerfest.com/forums/at...1&d=1590283589

N54 all the troubles of an N52 plus expensive turbo troubles.

And the HPFP don't forget

[Chark-attack]

Originally Posted by Efthreeoh

So the DME box was opened at some point? Did you open it during the VCG replacement? I opened my DME box to gain more slack to get the wiring harnesses out of the way.

So when you bought the car from your brother in December 2019, did the car have drivability issues and ECU codes and you've been chasing them ever since? You've replaced everything in the VANOS system other than the drain-back valves, but at the same time replaced the valve cover and ESS, yet you think it needs another new ESS? Nothing is making sense. New plugs and coils too. The only thing I can think of is the VANOS drives on the cams are suffering from the somewhat common broken bolt issue. You had the valve cover off did you check the bolts on the VANOS drives.

So when you say "clean the sun(roof) drains" what does that mean? Just the front drains? Did you clear the rear drains as well? They are hard to get to since they are way in the back of the sunroof cartridge and you'd need a very long piano wire to get down into the drains.

Also, do you know about newtis.info. That website has all the BMW tech info to help test and diagnose the issues the car is having.

Just trying to help.

Hi, thank you up front for the response and the help.

I definitely opened the dme cover during the VCG service, but it was inside a garage for the duration of that. I dont have a reasonable explanation for how water ended up inside of there other than possibly clogged runoffs directly next to the dme box.

During my brothers ownership, the car would intermittently die on him and leave him stranded. He replaced the battery but it would continue happening. Eventually he purchased another vehicle and so I towed it down to the shop I used to work at. We initially chased down a rather extreme parasitic draw (4 amps, literally). Was in a no crank, no start status. Replaced coils and plugs and was able to get it started and drove it around the property trying to let it work through some rough idle. I wasnt aware of the water in the back issue at this point and I think during this test drive it poured forward and eventually fried the transfer case module.

I replaced the ESS but it was a used one from a nearby seller parting a vehicle out. I didnt realize at the time the importance of this damn sensor and couldnt quite afford a brand new one at 250+ and thought it would be fine. But clearly that was a mistake, hence the need for a new one. I'm not familiar with the drain back valves, or where they're located in order to clean them. I can look that up though.

I did not check the bolts you're referring to while VC was off. I'm still learning about engines in general and BMWs specifically. I've read about the bolts but not in extensive detail to where I've retained the information.

As far as sun roof drains, I have only cleaned the fronts. I didnt realize there are rears, actually. None of the videos I've watched have mentioned them. But that's the parks of watching youtube repairs lol.


I'm familiar with Newtis but I've only used it for wiring diagrams and locations for electrical modules/connectors. I havent used it for troubleshooting or diagnosing. It's not the most mobile friendly site.

I scanned my car at work today but just realized I left the printout at the shop. I'll grab it Monday but there were 4 thrown vanos related, 2 active 2 stored. Cam synchronization iirc.

Edit: these were what was thrown when I scanned from home back in late June.
https://ibb.co/HP1pTQ1

I've got bimmergeeks protool master license that I've been using to scan/code from home.

[Jeff123]

I have had water ingress from the passenger side front doors on both an E90 and an F30. Both cases were due to the membrane inside the door. The F30 was as a result of a botched change of a broken window and the E90 just developed a leak over time. The E90 was c5 years old at the time and needed a new membrane. the F30 was only two years old and the membrane could be just re-attached.

The E90 had got be parked facing uphill to prevent water ingress.

That could be your issue.