[CarlosAC]

I don't post much, but I figured I'd go ahead and share some of the problems, symptoms, and repairs I've encountered over the years. A little background: I have had my '07 328i (6-speed) since 2009 and have put 144,000 miles on it. The car is pure stock and runs like a dream. While I'm not a certified mechanic by any means, I did work on jets for 21 years and I have extensive experience repairing many different vehicles. Plus, I have stayed at a Holiday Inn Express once or twice. I've even completely restored a 1967 Camaro RS/SS. Basically, I'm mechanically inclined. So, here's what I've encountered over the years -

1. Took my car to the local repair shop (LRS) for the scheduled brake flush and was notified I had a fault in the system which didn't come up on the display. The fault was faulty engine cooling, which the shop said indicated time to replace the water pump and offered to do the work for only $1800. What a bargain.
I decided to do the work myself, replacing the pump, thermostat, hoses, and of course the coolant. Total invested - $500. Worst part was accessing the hose clamps under the car for the thermostat. Not a difficult job, but time-consuming. I would suggest anyone tackling this job to be sure to place the clamps in a better position upon reassembly for any future work. In the end, I did notice my oil temp dropped about ten degrees from what it had run before the change.
Be sure to turn the car ON, but not start the engine, and the water pump will purge the system of any air. Kind of weird hearing the car do its own adjustments but it is real and it works. Monitor the fluid level as the bubbles come out.

2. Oil leak at the front of the engine. I couldn't figure out where it was coming from, so I bit the bullet and took to the dealer. The mechanic said it was coming from the oil filter housing seal, a rather common leak. The repair coordinator said it would be $1250 and went away for a few minutes to see about a repair date. The mechanic (cool Mexican dude) pulled me aside and said it was a relatively easy job, then printed out the page from their manual to do the fix. One $18 gasket later and some new coolant, I did the job myself. This is quite an easy job which will take about two hours or so and requires few tools. The time is spent draining the coolant more than actually doing the repair.

3. Car starting was intermittent - sometimes it would start right up, sometimes it would just turn over. Battery was only a year old. A little internet research led me to think it might be the starter, which it was. Now this is a complicated job since the starter is buried below the intake manifold and the rear mounting bolt was a beeootch to remove. You might to employ one of your kids to remove it once loose because they have little hands.

I broke the job down into major steps on what to remove and added pictures with arrows to be specific. I created a PowerPoint of the major steps and laminated the pages so I could just flip through the instructions with dirty hands while I worked on the car. Overall, everything went pretty smooth. Advice - label or mark everything you disconnect to make it easier to reassemble. Use a silver Sharpie to mark plugs and connectors, so, for example, when reassembling, connector 12 goes into plug 12, and so on. Disconnect in numerical order, mark items, then go in reverse on reassembly.

4. Blower fan squeeking. Easy fix...replaced the blower fan and some sort of controller assembly it comes with. Fortunately, the new fan motor came with instructions, which I questioned at first (remove cup holder???) , but they were dead on. Fan runs great now.

5. Oil in #3 and 4 plug valleys. Oil kept pooling in just these two valleys, eventually overflowing onto the exhaust manifold creating the acrid burned oil/plastic smell. I used an inspection mirror to locate the leak was coming from the VVT motor just above the coils. I was quite worried about this job because I had read so much about the possibility of screwing up the timing when removing the motor. I carefully removed the motor keeping an allen key on the center shaft to keep it from spinning as I removed it, but it still made a ZING! noise when I took it out, unloading some spring. Yeah, I was worried, but put it all back together easily after replacing the gasket. Next was the startup with visions of the engine being off timing and exploding. I followed one guy's advice to just turn the ignition on for a minute and let the computer adjust the timing gear to where it should be. I tried it and listened to the car make some adjustments under the hood, then started it and it was perfect. I don't know if he was right or not, but it worked.

6. Intermittent misfire at idle. No fault codes. Sometimes the car would go a couple of weeks without a misfire, then it would happen again a few times at a light. Ran fine under acceleration and basically in gear. The misfire was obvious because I could see the sudden drop in RPM followed by the engine trying to stay alive and increasing the idle, then dropping. This one stumped me so I took it to the LRS. $150 later for the diagnostic, they couldn't find anything. Back to square one.
At this point I decided to buy one coil and move it from cylinder to cylinder, then drive it for some time to see if the stumble went away. With my luck, I figured I'd find the problem in #6, but fortunately, it turned out to be #4 coil. I went ahead and just replaced all the plugs and coils.

7. Occasional misfire at idle. Sometimes, the car would die if I pressed the clutch at low RPM, such as coming to a stop at a light. The car would start up right away though. This time, I did have a code, but it would only pop up every once in a while - Fault P-0174 Mixture Control 2 Lean. Doing some research, there are several things that it could be: plugs/coils, vacuum leak, fuel injectors, oxygen sensors, fuel pressure, MAF sensor, PVC hoses.
I eliminated the coils/plugs as they were pretty new although there's always that chance. I removed the injector bar and inspected the injectors - all looked good, although one could have been faulty, but I pressed on. Vacuum leak - didn't find any, but more on this later. O2 sensors...couldn't really check them, but I was prepared to start replacing them. Crankcase vent hoses...hard to reach or see, but they looked good when I removed them last time. MAF sensor - I decided this would be the first part to replace since it's very easy to swap and inexpensive.
After the replacing the MAF sensor, the car still screwed up. I was about to take the plunge and go the repair shop so they could rape me for $150 and hopefully find SOMETHING. Then, I thought about the vacuum thing again. Apparently, shops have some sort of smoke machine that blows smoke through the intake system to identify vacuum leaks. I though about using my Halloween fogger, but who knows what that might do to various sensors. Then I thought about taking my shopvac and using the blow side to force air through the intake and see if I could find a leak. IT WORKED. Turned out the connector just below the crankcase tube "T" was cracked. A little talcum powder in the area confirmed the slight breeze I felt with my hand. In hindsight, I should have replaced it when I did the starter.
So, I used my instructions for replacing the starter to get to the crankcase vent hose. It actually fell into two pieces as I removed it. BTW, they're available from O'Reilly for $28, made by Gates, or $92 from BMW. Three hours start to finish. Would have been less, except I connected the fuel injector connectors to the wrong harness plugs (yes, it's possible).

8. Latest issue (lots of issues now over a short period of time) - I recently started hearing and feeling a buzzing/humming noise with the accompanying vibration. Looking around, this seems to be a common issue.
So, here's how I broke down my troubleshooting: Vibration was starting at around 40mph and became worse the faster I went, but dissipated a lot when I took my foot off the gas. The vibration was noticeable in the rear view mirror and you could definitely feel it in the seat bottom. Gear selection made no difference. No pulling when driving or diving on breaking. I eliminated the transmission/clutch since the gearing wasn't an issue (40mph in 3rd or 5th = same vibration). No engine issues as revving to the approximate RPMs where I had vibrations yielded nothing.
Easy things first - I lifted the rear and spun the tires to listen for a dragging (stuck) brake pad/piston - nothing. Suspension seems tight, no broken boots. Next up - flex disc, which I really hoped was the issue, but it looked perfect. U-joints - the only one I could see clearly is the rear most and guess what? One of the bearing is destroyed. I assume the bearing are needle bearings and there appear to be none left in one of the bearing turrets, if that's what you call them. The center shaft is wiggling freely inside the cup end. If this is the cause of the problem, it explains why the vibrations are speed-determined (drive shaft speed), and not RPM-determined. Well, this should be an easy bearing swap, right? Nope. I did not know BMW bearings are not <easily> changeable. Not impossible, but not easy. All the shops I called in the DFW area, plus the stealerships say the entire shaft has to be replaced, and I don't even want to get into their cost estimates, which are always nebulous. There's one place in Houston that can rebuild it, but I don't have the time.
I shopped around a bit and have decided to order a replacement shaft, flex disc, and hardware from Turner Motorsports. FYI, they currently have free shipping on orders over $100, which this definitely is. They also include a prepaid label for the core return, which many places did not = more savings.
When all the parts come in and the repair is done (by me, of course), I'll update and let you know if that resolved the problem. I have a video in my cell phone of me inspecting the u-joint, close up, in the car and you can clearly see how it is damaged, but I don't believe the forum will let me post it. I can send it to anyone, if they like. Hopefully, I can post some pics of the damage.
Update 8/8/18. Got the new drive shaft, flex disc, and hardware from Turner yesterday (ordered Friday morning). Took about three hours to complete the job and the vibration is completely gone.
Update 12/14/18 A few months have gone by and no issues at all. Vibration is completely gone.

Anyway, I hope this helps anyone who may have a situation like I've had over time.

[Bimmer Pleaser]

$1800 for water pump and thermostat 😂? Dealership is probably cheaper.

[tlow98]

Nice, would you mind listing the part for the connector under the crankcase "t"? I can't quite visualize what you're referring to there.

Nice job on the repairs. You've basically encountered all of the normal stuff with these cars.

What mileage did your starter and water pump go out at?

[CarlosAC]

Originally Posted by tlow98

Nice, would you mind listing the part for the connector under the crankcase "t"? I can't quite visualize what you're referring to there.

Nice job on the repairs. You've basically encountered all of the normal stuff with these cars.

What mileage did your starter and water pump go out at?

For some reason, I couldn't post the picture of the "T", but here's the link if you want to look at it. The hose starts at the back of the engine and turns forward on the driver's side, then goes under the intake manifold runners. It splits into a "T" just above the throttle body. The down-leg connects just after the throttle body to the side of the manifold. The other part of the "T" continues forward to another connector.

View post on imgur.com

Crankcase vent hose - 144,000 miles
VVT gasket - 140,030 miles
Starter - 133,850 miles
Water pump - 126,700 miles

[unrulyteach]

Originally Posted by CarlosAC

For some reason, I couldn't post the picture of the "T", but here's the link if you want to look at it. The hose starts at the back of the engine and turns forward on the driver's side, then goes under the intake manifold runners. It splits into a "T" just above the throttle body. The down-leg connects just after the throttle body to the side of the manifold. The other part of the "T" continues forward to another connector.

View post on imgur.com

Crankcase vent hose - 144,000 miles
VVT gasket - 140,030 miles
Starter - 133,850 miles
Water pump - 126,700 miles

My 2011 335i replaced the water pump at 60k miles and starter at 62k miles after i noticed it was harder start after the car got warmed up. It was cpo.

[tlow98]

Originally Posted by CarlosAC

For some reason, I couldn't post the picture of the "T", but here's the link if you want to look at it. The hose starts at the back of the engine and turns forward on the driver's side, then goes under the intake manifold runners. It splits into a "T" just above the throttle body. The down-leg connects just after the throttle body to the side of the manifold. The other part of the "T" continues forward to another connector.

View post on imgur.com

Crankcase vent hose - 144,000 miles
VVT gasket - 140,030 miles
Starter - 133,850 miles
Water pump - 126,700 miles

Tight spread on those repairs! They all made it to respectable mileage, tho.

[CarlosAC]

I just added my latest issue - vibration - see item #8.

[CarlosAC]

Updated with fix for vibration.