I have been wondering about a few things that might cause (or contribute to) the strut tower mushrooming - lowered springs vs. 17 and 18 inch wheels (with the corresponding reduced tire sidewall). So, for those of you that have experienced non-catastrophic mushrooming and/or strut mount failure (failure that was not due to things like hitting a pothole; but occurred over time), please post what size wheel and tire (also include whether you had runflat tires) you were running during the period immediately before the mushrooming and/or strut mount failure was noticed. Also, please post whether you have the stock springs or lowering (and presumably progressive rate) springs were installed on the car.

Thanks in advance to all who post.

Summary from posted information:

17 inch wheels + runflat tires (presumably 205/45-17s) + stock suspension:.........1

 

No crack in the strut tower but had mushrooming at the last check in at the dealer.

17"
Runflats
stock suspension.

 

As someone who worked on many cars with that issue,

I can tell you from our experience, that it does not matter what size wheel or what springs you are running.
It seems that the problem is due to a combination of things,
1) the factory suspension is way too stiff, and the factory shocks do not absorb the bumps like they are supposed to.
2) There is a problem with the design and the construction of the shock towers themselves.

So here are our suggestions, to prevent this from happening,
1) Change to a better quality shock (I am not going to name any)
2) Install a strut tower bar or reinforcement plates.

Hope this will help
Victor

 

I just added a poll to this thread to make the data collection easier. There are some additional options in the poll.

If you had both mushrooming and strut mount cracking you may vote for two different options so you can record your configuration for both issues.

 

A third suggested modification may be to go to a combination of 16 or 15 inch wheel with non-runflat tires. Lets see what the data show.

 

Thank you! A poll summary is much more efficient than my manual efforts at summarizing the poster's input.

The poll feature is an absolute trip! So far, it seems that the ticket to avoiding the mushrooming and/or strut mount failure is to go with 16 or 15 inch wheels and non-runflat tires and the stock suspension.... Wonder if that trend will hold....

 

Heh. There should be an option for poor quality roads as well.

 

My '05 MCS with 25,000 miles on it - everything is perfect.

My new GP with 2,500 miles on it - slight upward crease (about 2.5 inches long) in top of driver side strut tower (passenger side perfect).

Go figure. The only thing that comes to mind is that hidden expansion joint in Route 66 during one of the MTTS legs ... "bam" that was a doozy!

 

Why do you think adding a awaybar will help prevent strut tower mushrooming?



The idea here is excellent, but you realize that it is somewhat faulted? Probability will be affected by the number of miles driven, type of road, and, the number of respondents as a ratio to the actual number of cars on the road and voter participation. but then, the poll would take three years to complete.

 

I was just checking if you guys were paying attention

We meant Strut tower bar,......NO sway bar

Sorry for the typo

Victor

 

I don't think the objective is to get to 95% confidence (at least that wasn't my objective). Rather, a general trend of things to consider as likely contributing factors was my objective. At this preliminary stage, it does seem that with things like 17 inch or higher wheels, runflat tires and lowering springs on the car, you have higher chance of mushrooming and/or strut mount cracking/tearing.

Again, thank you to everyone who participated in the poll.

 

How is your '05 MCS equipped? And, I hope you participated in the survey.

 

Yes, I participated in the survey. Here is a link to another thread with full description on how my '05 MCS is equipped:

https://www.northamericanmotoring.co...ad.php?t=78117

 

`02 MCS with 16" wheels for the summer and 15" wheels for the winter (pothole season) 37,000 smiles. No mushrooming or cracks.

`06 MCS with 16" wheels for the summer and 15" wheels for the winter (pothole season) 9,700 smiles. No mushrooming, no cracks.

 

I had hoped the strut brace would help with the mushrooming Towers syndrome...we shall see...mean time it has changed the cornering of the MCS...for the better...for the better! I used the JCW only because I got a great deal on it!

 

My base model Cooper never had mushrooming happen, and the funny thing is, I had 16" wheels with lowering springs. To add to that, I had 45 series tires. I was so sure that I would get a cracked mount/mushroomed strut tower with this combo being that there wasn't a lot of rebound. Now I go and trade the base model in on a Cooper S, and it has mushroomed strut towers. The S has 17" tires with runflats and stock suspension.

 

Hey I'm off the chart!

mushrooming and cracked strut mount: lowering springs and aftermarket shocks / 19" non-runflat tires and strut tower bar.

The mushrooming if very minor so maybe the strut tower bar helped prevent it from being bad, or maybe it did nothing, fyi.

 

Passenger cracked, no mushrooming.

 

I thought I read some place that MINI made minor design changes that showed up in the 06's to prevent this from happening?

3k, 17" RF's....no issues

 

FYI.....

Got a call yesterday from a GP owner who had less then 1300miles on the car
with driverside mushrooming
He wasn't to happy to say the least. And yes he got some SRP's.

Peter
Team M7
562-608-8123

 

Well MINI did make the suspension on the GP's even more stiffer then your standard MCS and MCS JCW. Too stiff of a suspension will do such things but the driver I believe could be part of the problem. Try to avoid the potholes! These cars were not designed to take potholes very easily like my HEMI powerwagon for instance. If you can't avoid the landmine...pray!

 

True (about the '06 design change); but it didn't eliminate the problem, as some '06 owners have reported cracked/torn strut mounts.

 

Plus, 18 inch wheels, if memory serves....

 

I've been watching discussions like this with interest during the last two weeks.

Hmm, yes, those poll results are less than accurate. Of course very few cars with 18 and 19" rims have these problems. That's because there's a lot less of them out there to begin with.

My MC, with stock suspension and 16" RFs, has slight mushrooming on the right (passenger) side. That's because that side of the car takes all the abuse. The right edge of the road is where all the damage is from run-off and poor drainage. I remember a couple of teeth-rattling hits my car has taken on that side. No wonder there's some mushrooming on that side.

There's a set of M7 tower plates making their way to me as we speak.

 

My GP has a slight upward crease about two and a half inches long in the driver side top surface. My MCS (with over 25,000 miles) has totally smooth perfect top surfaces both sides. I know how to drive, I avoid potholes, I've owned many cars over the years and this "mushrooming" is a new one for me. I think what got my GP was a "hidden" expansion joint in the road on Route 66 during MTTS. Yes, I have a set of M7 SRP's coming in, too, putting them on next week after I massage the crease back into submission!