[relevante]

Hey all,

I've got a 2006 325xi wagon with just over 180k on it. It's been going strong since I bought it almost 4 years ago at 125k, other than a water pump failure over the summer that left me stranded (was lucky to have enough momentum to coast out of the left lane and straight into a gas station). I take total blame for that one though, as I knew it was time and just didn't take action.

I'd like to squeeze another year or two at least out of it as the daily driver (only car, actually). We've got 2 kids now though so I'm even more conscious of not wanting to get stuck on the side of the road. What should I do to avoid another instant failure like the water pump?

I've been doing all the typical routine stuff, fluids, etc. and have it apart in the garage now swapping out the rear wheel bearings right now as one just started to fail. I just ordered a new fuel pump since I'm sure it's also on its last breath. What else would be likely to fail and cause an immediate breakdown?

I was thinking of ignition stuff, and I will probably do it at some point but it seems like a lower priority since it's got individual coils for each cylinder and it sounds like it would at least get us home if/when one of those goes.

Appreciate any thoughts/discussion.

[cpie168]

What are the signs of a fuel pump about to die?

[relevante]

I've heard they can fail gradually causing sputtering and/or codes/service engine lights. Mine has been running fine, but I figure 180k miles and 10 years is a good sign it's about to go.

[Needbmwpartzz]

Invest in AAA/CAA best bet to not be stranded and Also get your family back safe and sound.......I'm a proponent of not looking for problems....if something is going to break/fail most will have no idea when...so just be reactionary and fix as needed....however you should follow scheduled maintenance and periodic inspection intervals.
Good luck

[El Cheapo Loco]

Keep a set of coils on hand as those are much cheaper to buy online.

[Efthreeoh]

If you are digging into a rear wheel bearing then I'll assume you've got some good wrenching under your belt. Get a BMW scan tool. That's the best way to keep track of these cars. The water pump most likely would have shown a BMW trouble code during a scan. Fuel pump, heck you never know; I'm at 293K and mine's still good. Fuel pumps usually start talking to you. Same for the starter (I'm jinxing myself here...). I lost my first coil at 287K (replaced all of them and new plugs). Then lost the left rear speed sensor. Now I think my right one has gone... Water pumps are about the only thing that'll really leave you on the side of the road. I went a over year and 45K plus miles on what eventually turned out to be a bad dual-mass flywheel.

[cliffschum]

I'm at 210K, and starting to hear what I believe is a high speed (above 40-50 mph) wheel bearing whine, but I can't determine which one is going bad. Hard turns don't help diagnose (L vs R), and I think it's a rear. Jacked up fronts, they spin fine. Can't spin rear since they're connected to axle.

Is there any visual method to narrow this down ?

Do rears often go first ?

How long can I drive vehicle without risk/damage ?

Thanks for any insight !

[Efthreeoh]

Originally Posted by cliffschum

I'm at 210K, and starting to hear what I believe is a high speed (above 40-50 mph) wheel bearing whine, but I can't determine which one is going bad. Hard turns don't help diagnose (L vs R), and I think it's a rear. Jacked up fronts, they spin fine. Can't spin rear since they're connected to axle.

Is there any visual method to narrow this down ?

Do rears often go first ?

How long can I drive vehicle without risk/damage ?

Thanks for any insight !

Diagnosing rear wheel bearings, or just any driveline noise, on these cars is difficult. The rear wheel bearing is just big sealed ball bearing (vs. roller, or tapered roller bearings), so it is difficult to know when they go bad. Hearing a slight change in noise at speed can be any number of things. My experience was this: I started getting a low rumbling sound at highway speed, which I thought was a rear bearing, it didn't change in sound on turns, as a tapered bearing would, but did change sound upon speed. The car was at 324,000 miles at that point, so based on that level of mileage I figured it was a rear bearing, but like you I couldn't determine which one, so I just replaced both (DIY). But the new bearings didn't solve the problem, so again, with the high mileage, I thought the diff was finally going bad, I found a decent low-miles used diff for $200, so I installed that, nope, STILL didn't get rid of the low rumble.

Well, next in line was the driveshaft. A few years before, when chasing down what eventually turned out to be a bad dual-mass flywheel, I had replaced the driveshaft center bearing assuming it was bad at 250,000 miles. So after the rear wheel bearings, and used diff install, I looked to the driveshaft again, now at 324,000 miles. Sure enough the center bearing was moving up and down in its mount, so I just replaced the entire shaft with a rebuild unit ($200) and that finally cured the problem. I figured the u-joints had served me well enough at 324,000, so a new rebuilt driveshaft was just $100 more in part cost than just the center bearing.

I know all those words probably doesn't help much, but I just wanted to point out trying to diagnose rear wheel bearings is quite difficult. And worst off is you'll never know if they were actually bad since you destroy the bearings getting them out. When I started getting my noise I was under the consideration of how far to let it go. Looking back I should have let it go longer, since there is no other damage cost-wise, there is no harm in letting it go longer to better help diagnose it. I'd first start with rotating tires to see if that changes the sound and then work from there.

[cliffschum]

Thanks very much for thoughtful reply. It's great to hear from someone with even more miles than me !

I initially believed tires were the problem. Didn't notice the noise until after I purchased 4 new Bridgestone runflat Driveguards, so I trucked back to Discount Tire to complain. He drove the car, kindly offered to swap tires, but we agreed this sounded more like wheel bearings than tire noise. More than likely, the noise has been increasing for awhile...I just could not hear it over the old tires .

I think I agree with you, I'll keep driving until it gets worse and more easily identifiable. We have a good Indy BMW trans shop here too, maybe I'll let them test drive and inspect on a hoist.

Just out of curiosity, have you replaced lower control arm bushings ?

Happy Holidays !

[Efthreeoh]

Originally Posted by cliffschum

Thanks very much for thoughtful reply. It's great to hear from someone with even more miles than me !

I initially believed tires were the problem. Didn't notice the noise until after I purchased 4 new Bridgestone runflat Driveguards, so I trucked back to Discount Tire to complain. He drove the car, kindly offered to swap tires, but we agreed this sounded more like wheel bearings than tire noise. More than likely, the noise has been increasing for awhile...I just could not hear it over the old tires .

I think I agree with you, I'll keep driving until it gets worse and more easily identifiable. We have a good Indy BMW trans shop here too, maybe I'll let them test drive and inspect on a hoist.

Just out of curiosity, have you replaced lower control arm bushings ?

Happy Holidays !

I replaced the front wishbones (lower control arms) at 336,000 miles. They really didn't need it. The bushings were cracked a tiny bit. The ball-joints were solid. All the bushings in the rear suspension are original except for the shock mounts both upper and lower.

[drawz]

If you have an oil filter housing gasket leak, fix it before it causes your belt to shred. Also check your belt tensioner as that can let the belt slip off.

I had an alternator fail and leave me stranded once, but I don't think I'd go after that preemptively.