[Topshelf1]

Hey guys, the wife's '06 325xiT with 60k miles feels very un-BMW like and I'm not sure what the problem is. The car feels floaty instead of tight while cruising. And worse, low speed bumps, especially a series of ripples, seems to wreak havoc on the front of the car. I took it to a dealer today for a test drive to see if they could narrow it down, and the only thing they will blame is the non-OEM tires. We bought the car used with stock runflats on it, I've had winter tires on it, and now I have brand new Grand Touring tires on it. It's felt the same under all conditions, so it's not the tires. Actually, it felt MUCH worse with the runflats. The new tires have definitely softened the car up a bit, but that's not where the problem lies. I'm thinking the struts are worn, but I find it hard to believe that 60k is all I'm gonna get out of the stock suspension. Dealer said 200k is standard (which I also find hard to believe). Any idea what is real world life span? Or better yet, what would cause this feeling?

Thanks

[Richwm]

Mine were shot at 70k but so were the tension struts. Before you ask look here http://www.realoem.com/bmw/showparts...15&hg=31&fg=05

Its #9 in this picture.

[Topshelf1]

Wow, seriously 70k and they were shot? Did you replace with OEM, or aftermarket? XI options are limited so I'll most likely go with overpriced OEM if that turns out to be the issue. Also, were yours leaking, or just worn? Mine are bone dry.

As far as the tension struts, I checked the XI design here and it's a little different. I'm guessing the traction strut (#8) is the closest part to what you are talking about. Out of curiosity, was it easy to notice your tension struts were worn? I know I can check my LCA's by rocking the front tire back and forth. Is there a simple test for the traction/tension strut? I'm thinking I'll have an indy throw the car up on a lift for a quick inspection before dropping any money into the suspension, but I'd love to test it myself if possible.

Thanks for the reply.

[Richwm]

Originally Posted by Topshelf1

Wow, seriously 70k and they were shot? Did you replace with OEM, or aftermarket? XI options are limited so I'll most likely go with overpriced OEM if that turns out to be the issue. Also, were yours leaking, or just worn? Mine are bone dry.

As far as the tension struts, I checked the XI design here and it's a little different. I'm guessing the traction strut (#8) is the closest part to what you are talking about. Out of curiosity, was it easy to notice your tension struts were worn? I know I can check my LCA's by rocking the front tire back and forth. Is there a simple test for the traction/tension strut? I'm thinking I'll have an indy throw the car up on a lift for a quick inspection before dropping any money into the suspension, but I'd love to test it myself if possible.

Thanks for the reply.

I installed bilstein HD struts.
If you lift the front of the car try and wiggle the front wheel if you get excess movement out of the bushings they are done you could just replace the bushings but I was able to just upgrade to the M3 parts. I feal that the shocks and struts have such a short life due to the heavy wheel and tire combo's used by BMW in there newer cars. My 162's with RFT's weighed 59 lbs compared to 35 lbs for my E46 wheels.

[Hoog_23]

Did you replace the strut mounts/bearings (or is that what you meant by bushings)?

[Richwm]

Originally Posted by Hoog_23

Did you replace the strut mounts/bearings (or is that what you meant by bushings)?

No I didn't change the strut mounts but I should have. The bushings I was talking about were the tension strut bushings or in your case the traction strut bushings.

[Topshelf1]

Thanks Rich. I'll check out the bushings this weekend. Are you happy with the Bilstein HD's? I'm a bit concerned about them being too stiff. Comfort is very important in the wife's car.

[enrita]

i just changed mine at 35K because i put on the M3 parts and they were worn out in the link connections.

[Topshelf1]

I'm sorry enrita, what exactly do you mean by "link connections"? Just want to make sure I'm understanding what seems to be wearing out. Thanks.

[Richwm]

Originally Posted by Topshelf1

Thanks Rich. I'll check out the bushings this weekend. Are you happy with the Bilstein HD's? I'm a bit concerned about them being too stiff. Comfort is very important in the wife's car.

They are stiff I also put them in my wifes car and she hates them.

[Richwm]

The bushings are #9 on your car.

[Topshelf1]

Thanks again Rich. I think it's the first time I've seen an honest answer to these HD's. Considered them for her previous E46 wagon as well. I'll just stick to OEM then.

I noticed that the bushing is only $45 compared to $120 for the entire traction strut. Is replacing the bushing relatively easy? I remember doing LCA bushings on her old car and it wasn't that bad at all. Just wondering if I can pop the old ones out and new ones in without a proper press.

[Richwm]

Originally Posted by Topshelf1

Thanks again Rich. I think it's the first time I've seen an honest answer to these HD's. Considered them for her previous E46 wagon as well. I'll just stick to OEM then.

I noticed that the bushing is only $45 compared to $120 for the entire traction strut. Is replacing the bushing relatively easy? I remember doing LCA bushings on her old car and it wasn't that bad at all. Just wondering if I can pop the old ones out and new ones in without a proper press.

The bushing is a similar design to the E46 RTAB bushings and having done those before and I will never do it again its just not worth my time. Plus you get new ball joints on the other end of the arm. I consider LCA's on a E46 a simple job and replaceing the Traction Strut very easy, 20 min a side after the car is on jack stands. Replaceing the bushings looks to be a pain in the ass without a proper press.

[Richwm]

FYI I just checked Crown Auto and they are $105.14 each.

http://www.crownpartsonline.com/part...?siteid=214334


Part Number: 31126768983 Core Price Your Price
Front suspension - Suspension components - Radius arm Radius arm, 3 series, left - awd 2006 - 2008
$0.00 $105.14

Part Number: 31126768984 Core Price Your Price
Front suspension - Suspension components - Radius arm Radius arm, 3 series, right - awd 2006 - 2008
$0.00 $105.14

[Topshelf1]

Man, I owe you one (maybe two) Rich! Appreciate all the help on this. Plus that Crown auto place is a bit cheaper for the struts as well. I know some bushings are easy, others not so much, so I'm all for just replacing the entire unit since that sounds like the way to go. Looks like I can get a decent spring compressor and ball joint remover for around $100-$120, so I'll have to go through my TIS cd to make sure there's no surprises waiting for me.

Just to be sure, is there anything else that should be replaced at the same time as the struts? Obviously the springs are swapped over. But looking at the diagram I'm not sure if I should invest into any other parts since I don't want to have to do this twice. Isn't there something between the strut and the tower that wears out? Guide Supports?

[mds82]

Mine lasted till i hit a HUGE pothole and bent the strut !!!! LOL

[Chowbow]

It might be time to change the strut mount too. I'm not sure how long they last in these cars. If you're going to do the shocks again in another 60k though, I would guess that the strut mounts will last til then. I'm talking about the big rubber mount that the strut bolts to, and the mount bolts to the strut tower via the 3 nuts in the engine bay. Over time those can break down and tear. I would assume they'd last over 100k miles, but don't quote me on it.

[Topshelf1]

Yeah, that's exactly what I was talking about. The one diagram called it a guide support, but I think I was looking at the wrong thing. Looks like Struts and Strut Mounts will run $600. Not too bad. I do want to check out those traction strut bushings this weekend though which would add another $200 to the cost. Only other thing I've seen mentioned that I need to look at is the front sway bar bushings. There's a thread in here where several people have mentioned that replacing them solved a crunching noise over speed bumps. Just not sure if they mean the small rubber bushings that require removal of the sway bar I think, or the swing supports it actually attaches too. Seems like 60k would be early for struts, but I've been searching the net and it's not as uncommon as I originally thought.

Oh, and how big was that pothole to actually bend a strut? That had to sound like a cannon going off in the car.

[enrita]

Originally Posted by Topshelf1

I'm sorry enrita, what exactly do you mean by "link connections"? Just want to make sure I'm understanding what seems to be wearing out. Thanks.

the soft bushings inside the arms like 15 on picture .

[Chowbow]

Originally Posted by Topshelf1

Yeah, that's exactly what I was talking about. The one diagram called it a guide support, but I think I was looking at the wrong thing. Looks like Struts and Strut Mounts will run $600. Not too bad. I do want to check out those traction strut bushings this weekend though which would add another $200 to the cost. Only other thing I've seen mentioned that I need to look at is the front sway bar bushings. There's a thread in here where several people have mentioned that replacing them solved a crunching noise over speed bumps. Just not sure if they mean the small rubber bushings that require removal of the sway bar I think, or the swing supports it actually attaches too. Seems like 60k would be early for struts, but I've been searching the net and it's not as uncommon as I originally thought.

Oh, and how big was that pothole to actually bend a strut? That had to sound like a cannon going off in the car.

60k is early, but on an OEM item it's not too surprising. As much as the car is performance oriented there are bean counters and lowest bidders at work. On a family member's Benz, the stock struts were done after about 50k miles.

You might want to check out the Koni FSD shocks. They are supposed to ride better than the stock monotubes and have special valves that can detect the difference between "high frequency" bumps in the road vs. "low frequency" compression through turns. Lots of people praise it, but I don't know how it really compares to the OEM struts. If anything, I would think that they'd last longer than the OEMs, maybe 100k if you're lucky.

EDIT: And I have the Bilstein HDs. I can just about guarantee your wife will not be happy if you put those in. They're a good amount stiffer than OEM, and handle way better but ride quality is definitely worse in terms of compliance. It's better in that the car reacts quickly and recovers quickly to bumps, but that, in most people's butts, translates to a bumpy / harsh ride.

[Topshelf1]

Unfortunately, Koni FSD's are not available for either the wife's 325xi, or my Z4C. Otherwise both would have them installed right now. I still find it odd how small their application list is for those things.

Between the weather and my schedule this weekend I'm not too sure I can get the car in for a checkup from the indy. Really want to get this taken care of soon, so I'll let you guys know what I find out on this. Almost just want to change the struts for the fun of it now.

[Topshelf1]

Just wanted to update this in case someone else gets to this point. I replaced both front struts and strut mounts over the weekend with OEM replacements. Difference in the car is night and day! Before the car rattled up front over bumps and didn't seem tight or settled over a series of ripples. Car now feels planted like a BMW should. I couldn't feel any difference in the old/new struts when off the car, so I don't think those old tests mean anything. I also noticed a considerable amount of play in the drivers side mount. We bought the car with 52k miles, have been upset with the ride quality for the last few months and finally changed struts at 64k miles. So I'm officially in the OEM struts last 60k miles camp now.