[saebsaeb]

Hey guys I'm looking at buying a E90 330i that is almost perfect. The only thing I noticed was when I was underneath it has some rust on the subframe. I am wondering how big of a deal this is for someone that has delt with rust before on their own? If I could get most of it off with a wire brush? Or if it will keep getting worse?

Or if I would need to replace the subframe eventually? How much would that cost if so? Also when I was looking it looks like the bushing that attaches is worn out and you can see the metal to metal wear. I am worried if this is not the only bushing that is worn out. Is there others I should look out for? On top of all of that if I can replace the bushing myself easily? Any links to a good bushing would be appreciated. (the hole beside the bushing is supposed to be there it is not rotted out)

[mweisdorfer]

Originally Posted by saebsaeb

Hey guys I'm looking at buying a E90 330i that is almost perfect. The only thing I noticed was when I was underneath it has some rust on the subframe. I am wondering how big of a deal this is for someone that has delt with rust before on their own? If I could get most of it off with a wire brush? Or if it will keep getting worse?

Or if I would need to replace the subframe eventually? How much would that cost if so? Also when I was looking it looks like the bushing that attaches is worn out and you can see the metal to metal wear. I am worried if this is not the only bushing that is worn out. Is there others I should look out for? On top of all of that if I can replace the bushing myself easily? Any links to a good bushing would be appreciated. (the hole beside the bushing is supposed to be there it is not rotted out)

A new subframe isn't cheap. You could easily get a used one in pretty good condition on eBay.

Maybe get it sandblasted & powder coated. That wouldn't all that expensive.

[feuer]

Don’t touch unless you really have to.

[saebsaeb]

don't touch as in don't buy the car or don't mess with the rust?

[F13.KENN]

I have a 128i from up north that has about the same amount of rust on the rearend as you. Maybe a little more.

This is the first and last northern car that i will ever buy. Cant even get an alignment. Has abs sensor issues like crazy, and lots of the hardware on the car is corroded. Its been a headache

[jwrag2000]

I checked my own subframe and it's almost identical to this one with a hole in exactly the same place, next to the lower, rear most, drivers side bushing.

I'm planning in the medium term to replace the whole subframe with either a remanufacured OEM part or with a completely new third party item. Which do we think is best, remanufactured OEM or new third party?

Remanufactured
https://www.ebay.co.uk/itm/314913134...Bk9SR9jJ1NrkYw

New
https://www.ebay.co.uk/itm/155522894...Condition=1000

[wrevilo]

Lots of people have built up a subframe to swap in with their car. However, this isn't necessarily cheap depending on the work undertaken and chosen bushes. See this thread as an example.

https://www.babybmw.net/threads/e87-...bframe.110723/

I have considered doing it, but it is a lot of work to source a subframe in decent condition, have it blasted and painted, and then source and fit all of the required bushes. I'd be hesitant of buying a subframe that was already remanufactured as you won't be able to see if there are any issues under the paint.

[jsunma]

Originally Posted by jwrag2000

I'm planning in the medium term to replace the whole subframe with either a remanufacured OEM part or with a completely new third party item. Which do we think is best, remanufactured OEM or new third party?

Actually, neither...until you've tried to find a used part. I found a perfectly good (i.e., no rust) rear subframe for my car that cost about half of what you're quoting for a "remanufactured" part.

The subframe is nothing but a big piece of welded metal tubing. There's nothing to remanufacture. If it's free of perforating rust and the bushings are in good shape (or you simply buy new bushings and replace them), you're done.

I replaced mine for about $250 in subframe parts with a junkyard part. I brushed off surface rust and treated that. There is an argument that you really shouldn't "blast and refinish" these things if they're in good shape as you're probably causing future problems by blasting them...unless you want to spend more than the part is worth powder-coating it.

Fact is, some of these last for years and years serious rust-free. Others fail earlier. I think that in general there's relatively little data on failure (rust) rates since most of these cars are turned in/disposed of well before the 10 year point when such rust begins to emerge. You don't say what year your car is, but mine is a 2008 and its subframe was toast at about 12 years.

Here's another thread that may be of help: https://www.e90post.com/forums/showt...ubframe+jsunma

[eljay]

Originally Posted by jsunma

Actually, neither...until you've tried to find a used part. I found a perfectly good (i.e., no rust) rear subframe for my car that cost about half of what you're quoting for a "remanufactured" part.

The subframe is nothing but a big piece of welded metal tubing. There's nothing to remanufacture. If it's free of perforating rust and the bushings are in good shape (or you simply buy new bushings and replace them), you're done.

I replaced mine for about $250 in subframe parts with a junkyard part. I brushed off surface rust and treated that. There is an argument that you really shouldn't "blast and refinish" these things if they're in good shape as you're probably causing future problems by blasting them...unless you want to spend more than the part is worth powder-coating it.

Fact is, some of these last for years and years serious rust-free. Others fail earlier. I think that in general there's relatively little data on failure (rust) rates since most of these cars are turned in/disposed of well before the 10 year point when such rust begins to emerge. You don't say what year your car is, but mine is a 2008 and its subframe was toast at about 12 years.

Here's another thread that may be of help: https://www.e90post.com/forums/showt...ubframe+jsunma

Agreed!

OP, find a good condition used subframe and replace bushings as needed.
See my post on the topic: https://www.e90post.com/forums/showp...&postcount=392

[marvinstockman]

Walk away, or maybe run away!

[jwrag2000]

Ok, used subframe then. Where would you get the bushings? BMW, Autodoc?

[sowbmw]

I haven't dealt with that level of rust, but I did replace all arms in the rear and let me tell you that it was very difficult. For some reason, pretty sure it's salt and age, the bushings corrode and fuse to the subframe. I had to use a lot of heat to melt the rubber bushing then cut it out with a reciprocating saw. It took about a day or more to do.

I used OE bushings and arms when replacing. If you find a good deal on a subframe, it wouldn't be too bad to drop the old subframe and replace. I would recommend treating the subframe that you get to avoid future issues. Right now I tend to fluid film everything except for the rubber.

I use Rockauto, fcpeuro and BMW to source bushings. OE or equivalent is what I like to use, but other's prefer aftermarket.

[oVeRdOsE.]

subframe rust wayyyy faster than the body, so the body and frame might be good.

you can find a subframe at the salvage yard, it wont be that expensive.
rust converter + oil based spray paint and good to go.

change all bushing while you're there, I took mine from EuroSport Tuning in Ontario, I use powerflex.

It's not a hard job, but time consuming for sure.