Cracking on the strut tower. Seam sealer?

[vaz4]

I’ve been told this was just old Seam sealer, but wanted to get a few more opinions before I write it off in my mind.
Tiny cracks on each side of the base corners of the strut towers. The car has not been in an accident or tracked. Should I fill those cracks up with fresh sealer? I haven’t seen any instance of strut tower failure on a z4 so I’m assuming it’s just what I think it is, but is this common?

 

[smorris_12]

Without scraping it back you'll never know.

I'd not be surprised at a tower seam tearing as the e85 suspension is very unyielding

 

[Mr Tidy]

If the sealant has cracked there must have been some movement.

As Scoot says you need to get it off and see what is going on underneath. I'm sure I've read of Z4s having cracking issues on the strut towers.

 

[vaz4]

I’ve been searching all over the place and can’t find any real issues with z4 strut towers except early examples have the strut brace break at the mount on top. The area I live in does have rough roads but I don’t drive too crazy. I know this stuff could theoretically crack from it aging(drying and shrinkage) but what you guys are saying also sounds like a real possibility. I just wonder how many others have seen this because I’m shocked I can’t find anything. I will take you guys advice and give it a check but Im worried about how much of a mess I’ll make especially if it ends up being fine. Better off safe than sorry for sure!

 

[Nick W]

Clean it back to bare metal, If they are cracks then drill out the ends and weld up. Prime but don't hide with sealer yet, just keep an eye for more cracks. Fit a couple of E46 strengthening plates, Have a cuppa, then take it out and show it who's boss.

 

[Rockhopper]

Leave it well alone in my opinion. Its an old car, there is bound to be some movement and the sealer will go hard over the years. Z4's have zero history of suspension mount cracks. If you cannot replicate the factory seam sealer finish (poor though it is) a future buyer will assume the car has accident history.

 

[jock156]

Strange...................

I noticed on Friday my drivers side has come completely loose, no cracks just one big gap

Haven’t hit anything that I’m aware of

What’s the best course of action?

Apologies for the hijack

 

[B21]

I’ve been searching all over the place and can’t find any real issues with z4 strut towers except early examples have the strut brace break at the mount on top. The area I live in does have rough roads but I don’t drive too crazy. I know this stuff could theoretically crack from it aging(drying and shrinkage) but what you guys are saying also sounds like a real possibility. I just wonder how many others have seen this because I’m shocked I can’t find anything. I will take you guys advice and give it a check but Im worried about how much of a mess I’ll make especially if it ends up being fine. Better off safe than sorry for sure!

Strange …a simple search shows many examples of quite bad cracking on E85 strut towers…many forums carrying details…FWIW I’d get it checked out pronto…

As an aside earlier BMWs had lots of issues with the towers flexing..causing steering / handling related issues…hence the cracking…

 

[enuff_zed]

Strange...................

I noticed on Friday my drivers side has come completely loose, no cracks just one big gap

Haven’t hit anything that I’m aware of

What’s the best course of action?

Apologies for the hijack

Brian, we can check it out when you come over. Unless you think it's a crack in the metal rather than just the sealer? In that case if it's as big as you say then you don't want to be taking it far!

 

[jock156]

Thanks EZ, the strut is completely separate from the tower!

You can move the end of the strut up & down, not by much, but you can move it

 

[enuff_zed]

Thanks EZ, the strut is completely separate from the tower!

You can move the end of the strut up & down, not by much, but you can move it

Got a pic? Do you mean the rubber inside the top mount? Don’t drive it anywhere yet!!!

 

[enuff_zed]

Sounds like a failed top mount. But need to see it first.

 

[jock156]

Ill get a photo when the rain stops

 

[vaz4]

I’ve been searching all over the place and can’t find any real issues with z4 strut towers except early examples have the strut brace break at the mount on top. The area I live in does have rough roads but I don’t drive too crazy. I know this stuff could theoretically crack from it aging(drying and shrinkage) but what you guys are saying also sounds like a real possibility. I just wonder how many others have seen this because I’m shocked I can’t find anything. I will take you guys advice and give it a check but Im worried about how much of a mess I’ll make especially if it ends up being fine. Better off safe than sorry for sure!

Strange …a simple search shows many examples of quite bad cracking on E85 strut towers…many forums carrying details…FWIW I’d get it checked out pronto…

As an aside earlier BMWs had lots of issues with the towers flexing..causing steering / handling related issues…hence the cracking…

B21 I’m struggling to find the posts you’re referring to although maybe I’m using the search bar incorrectly. The only posts I can find related to strut tower problems with the e85 are related to the brace on the top of the mount cracking and breaking at the joint. Can’t find anything like this. On this site or anywhere else. I would like to think what rock hopper is saying is the case but the main reason for that really is I’d hate for the car to look like it’d been in an accident with a s*** repair job or something. Now obviously if I am having a problem it needs to be addressed and looked at but now I’m leaning toward maybe checking from the inside? I was going to replace struts soon anyways so perhaps I could look inside the tower

 

[B21]

‘bmw e85 strut tower cracking” Into Google

 

[vaz4]

‘bmw e85 strut tower cracking” Into Google

I’ve been researching this for days and you think I haven’t done that? Lol, sheesh……. Feel free to post links since you know so many examples. Again, I am not referring to some of the documented issues with the top mounts and brace. This is obviously not a common issue

 

[B21]

‘bmw e85 strut tower cracking” Into Google

I’ve been researching this for days and you think I haven’t done that? Lol, sheesh……. Feel free to post links since you know so many examples. Again, I am not referring to some of the documented issues with the top mounts and brace. This is obviously not a common issue

As others have said, without scraping the sealant away to see the metal you will never know for sure..yes there are lots of top mounts cracking but I see others with cracks elsewhere..given the known flexing of the tower structure and how metal fatigue is insidious I wass proferring a view on the side of caution..if you've owned the car from new then maybe you know its history, otherwise who knows what and whyen and how often the structures have been stressed...

You should take a chill pill..folks here are only trying to help...

 

[vaz4]

‘bmw e85 strut tower cracking” Into Google

I’ve been researching this for days and you think I haven’t done that? Lol, sheesh……. Feel free to post links since you know so many examples. Again, I am not referring to some of the documented issues with the top mounts and brace. This is obviously not a common issue

As others have said, without scraping the sealant away to see the metal you will never know for sure..yes there are lots of top mounts cracking but I see others with cracks elsewhere..given the known flexing of the tower structure and how metal fatigue is insidious I wass proferring a view on the side of caution..if you've owned the car from new then maybe you know its history, otherwise who knows what and whyen and how often the structures have been stressed...

You should take a chill pill..folks here are only trying to help...

A chill pill? For simply replying to your smart*** reply asking for the links you keep referring to? I’ve highly appreciated the helpful responses I’ve received and I’m on here to help document an issue I have barely seen on these cars. I don’t need to deal with some stereotypical forum bully…. I’ll be going forward with most of everyone’s suggestions to chip it away and check to be safe and will be reporting this back to as many sites and I’ve been apart of since owning the car. Hoping this will get everyone checking their own car as I have no idea how long these have been there and I will hopefully be able to guide anyone through their own diagnosis. I just wanted to get as much information as possible and experiences as possible before I go hacking away at this stuff. Like you said, this is relatively common on older bmws but as rockhopper said it’s almost non existent on these cars. Hoping it ends up being nothing bad.