Rattle inside silencers

[stuartinzg]

I have been noticing a very annoying rattle and vibration for a while now. I thought at first it might be the new tips I installed, so I had them welded on and still it persisted. It was rattling at idle, but under half load it also made a strange noise like metal pieces flapping around.

Took the car to the shop today and we put it up on the ramps to start banging around.

Turns out the rear silencers have rust parts inside them (both silencers)- when you hit them with your hand, and also further down, hitting the secondary cats, they make the same noise as at idle.



I think my warranty just ran out too. Might be a good reason to get that Eisenmann race finally?

 

[35i-Nut]

Man thats a bummer

I'm debating to get a custom made system with secondary CAT delete , prices are coming in at around £550

Also looking to just get the OEM tips cut off and new tips welded on £140

Although the eisenmann system is nice , just cant justify £1400 !

Also been looking a this system which is more resonably priced -

http://www.ebay.co.uk/itm/Fox-Sports-Exhaust-Duplex-Stainless-steel-BMW-Z4-E89-sDrive-35i-225kW-1x100mm-/272213446464?fits=Model%3AZ4&hash=item3f612f8f40:g:mkIAAOSwyQtV4Cjl

https://www.youtube.com/watch?v=FYmiJ9_LjKI

 

[Maniac]

Thankfully I had a full system replacement at year 3 due to the exhaust flap failing. Still, my car has done a lot of very short trips and I suspect that will reduce the lifespan quite a bit.

 

[john-e89]

It looks and sounds a fantastic system Stuart, I suppose it depends if your cars a keeper and affordability obviously, from what you've already done I'd guess it is for the foreseeable sooo go for it, your car deserves no less...

 

[stuartinzg]

It looks and sounds a fantastic system Stuart, I suppose it depends if your cars a keeper and affordability obviously, from what you've already done I'd guess it is for the foreseeable sooo go for it, your car deserves no less...

Hi John,

Yes I would love it, but I would also love the LSD, which would provide a lot more value for money in the performance stakes.
I can't justify spending £3000 extra on the car this year, so I'll have to pick and prioritise!
Temped to take the exhaust off and try and shake the rust out, or cut open the silencer and re-pack it.

 

[john-e89]

It looks and sounds a fantastic system Stuart, I suppose it depends if your cars a keeper and affordability obviously, from what you've already done I'd guess it is for the foreseeable sooo go for it, your car deserves no less...

Hi John,

Yes I would love it, but I would also love the LSD, which would provide a lot more value for money in the performance stakes.
I can't justify spending £3000 extra on the car this year, so I'll have to pick and prioritise!
Temped to take the exhaust off and try and shake the rust out, or cut open the silencer and re-pack it.

Well if you've got access to a welder etc, that sounds the only short term option other than buying new boxes Stuart, I would'nt imagine 35is exhausts are littering the breakers yards, especially where you are.

Is it worth doing a find-a-part search on the interweb as a stop gap?

BTW are you still going to the Watermill meet next month? I'm looking doubtful as having some un-expected surgery on 3rd August, it's got to stay an open internal wound and self heal so it's not looking good, pissed off as I was looking forward to that chat and seeing your mods. Not definate though so fingers crossed.

 

[techathy]

Are you getting the same sound from the secondary cats? If so you may not have a problem with the silencers at all. Given what my Z4 is doing with 'correct' fueling & given the Thunderclaps like Thor... thread I'd suggest the secondary cats may have got scorched and started to fall apart. Now debris from this has made its way into the back boxes.

So you're car is auto-decatting?.. be happy people pay money for that

 

[stuartinzg]

It looks and sounds a fantastic system Stuart, I suppose it depends if your cars a keeper and affordability obviously, from what you've already done I'd guess it is for the foreseeable sooo go for it, your car deserves no less...

Hi John,

Yes I would love it, but I would also love the LSD, which would provide a lot more value for money in the performance stakes.
I can't justify spending £3000 extra on the car this year, so I'll have to pick and prioritise!
Temped to take the exhaust off and try and shake the rust out, or cut open the silencer and re-pack it.

Well if you've got access to a welder etc, that sounds the only short term option other than buying new boxes Stuart, I would'nt imagine 35is exhausts are littering the breakers yards, especially where you are.

Is it worth doing a find-a-part search on the interweb as a stop gap?

BTW are you still going to the Watermill meet next month? I'm looking doubtful as having some un-expected surgery on 3rd August, it's got to stay an open internal wound and self heal so it's not looking good, pissed off as I was looking forward to that chat and seeing your mods. Not definate though so fingers crossed.

Yes I'm definitely coming. Bringing my father along too as I haven't seen him all year.

Hope you can make it, sorry to hear about the unexpected surgery, bit of a bugger

 

[stuartinzg]

Are you getting the same sound from the secondary cats? If so you may not have a problem with the silencers at all. Given what my Z4 is doing with 'correct' fueling & given the Thunderclaps like Thor... thread I'd suggest the secondary cats may have got scorched and started to fall apart. Now debris from this has made its way into the back boxes.

So you're car is auto-decatting?.. be happy people pay money for that

You are probably right - because the noise is not really that pleasant

The Eisenmann removes the secondary cats and replaces them with what looks like a resonator.

Doh

 

[stuartinzg]

Quick update, now I'm in the UK I hunted around and found this chap: www.exhaustmods.co.uk I'm booked in for Friday.

He will take out the secondary cats and cut open my silencers, fix all the issues and put it all back together again.

Gives me a bit more time to sort out another exhaust rather than rushing as MHD Stage 1+FMIC seems a better option (additional cooling from the Evo FMIC) which would provide more tangible benefit for less money, given I am still trying to save for that Caterham

 

[john-e89]

Hey Stuart,

No hope of making it to the watermill, gutted, have a great day and thanks very much for offering me a try of your fettled car, was really looking forward to the differences to stock. Hopefully another time.

Take plenty of pics please.

 

[stuartinzg]

Hey Stuart,

No hope of making it to the watermill, gutted, have a great day and thanks very much for offering me a try of your fettled car, was really looking forward to the differences to stock. Hopefully another time.

Take plenty of pics please.

Doh! Hope you get better soon. Where are you based? If you aren't too far from Long Sutton is there the option for a pub visit on Saturday?

 

[john-e89]

Hey Stuart,

No hope of making it to the watermill, gutted, have a great day and thanks very much for offering me a try of your fettled car, was really looking forward to the differences to stock. Hopefully another time.

Take plenty of pics please.

Doh! Hope you get better soon. Where are you based? If you aren't too far from Long Sutton is there the option for a pub visit on Saturday?

I'm in Derbyshire in the Peak District Stuart, too far and at the moment I'm bed ridden, 32 tablets inc' injections a day, like a zombie!

Cheers for the thought though, next time your in Blighty we'll have a meet up & a pint.

 

[stuartinzg]

Hey Stuart,

No hope of making it to the watermill, gutted, have a great day and thanks very much for offering me a try of your fettled car, was really looking forward to the differences to stock. Hopefully another time.

Take plenty of pics please.

Doh! Hope you get better soon. Where are you based? If you aren't too far from Long Sutton is there the option for a pub visit on Saturday?

I'm in Derbyshire in the Peak District Stuart, too far and at the moment I'm bed ridden, 32 tablets inc' injections a day, like a zombie!

Cheers for the thought though, next time your in Blighty we'll have a meet up & a pint.

Blimey, sounds serious

Yep, I will be back nearer Christmas or failing that next year. Car will be better then too

Get well soon

 

[techathy]

I'm in Derbyshire in the Peak District Stuart, too far and at the moment I'm bed ridden, 32 tablets inc' injections a day, like a zombie!

Cheers for the thought though, next time your in Blighty we'll have a meet up & a pint.

Blimey, sounds serious

Yep, I will be back nearer Christmas or failing that next year. Car will be better then too

Get well soon

Can only re-iterate that. GWS!

 

[john-e89]

I'm in Derbyshire in the Peak District Stuart, too far and at the moment I'm bed ridden, 32 tablets inc' injections a day, like a zombie!

Cheers for the thought though, next time your in Blighty we'll have a meet up & a pint.

Blimey, sounds serious

Yep, I will be back nearer Christmas or failing that next year. Car will be better then too

Get well soon

Can only re-iterate that. GWS!

Thanks very much chaps.

 

[stuartinzg]

Saw an exhaust specialist yesterday, they are going to fabricate a completely custom unit from the downpipes back. Resonator in the mid and two new boxes at the back, similiar style to the Eisenmann design.

Due to be completed within 2 weeks, keep you posted

 

[john-e89]

Saw an exhaust specialist yesterday, they are going to fabricate a completely custom unit from the downpipes back. Resonator in the mid and two new boxes at the back, similiar style to the Eisenmann design.

Due to be completed within 2 weeks, keep you posted

Hey Stuart,

Is that a system in the UK or are you back abroad?

 

[stuartinzg]

Saw an exhaust specialist yesterday, they are going to fabricate a completely custom unit from the downpipes back. Resonator in the mid and two new boxes at the back, similiar style to the Eisenmann design.

Due to be completed within 2 weeks, keep you posted

Hey Stuart,

Is that a system in the UK or are you back abroad?

It's being built abroad where I am based. They have done a lot of special cars as well as run of the mill. All top quality materials and a fraction of the price of the German equivalents. I'll keep proper picture diary of it and show videos afterwards. We expect to tweak it to make it perfect. Once done they can ship a set anywhere if anyone here is interested, I can put together a group buy afterwards.

 

[stuartinzg]

Quick update on this. Car was in the shop all day today. They started building the exhaust - using some of the existing pipework which is stainless already. They will add a resonator where the secondary cats were to reduce the rasping and then two new back boxes with bigger tips which are not bolted on over the top of the old pipe.

The idea is to make it loud and nice, but not horrible and farty (as it currently is, with an almost straight pipe). But... we've since been discussing other options and it looks like I will add in an upgrade to add two electronic valves which I can then switch via a simple switch in the dash, probably added to where the money tray/charging port is. Wireless on a key fob is also an option, but I would prefer a fixed unit.

Then I can have the option for very quiet, normal, loud !

Hopefully pickup the car tomorrow, sans valves, to see how it is (needs to be loud to start before adding valves), then we can take it from there.