GS450h rear silencer has fallen off

[pgg450h]

Evening all,

I have been aware of some corrosion on the outer skin of one side of the rear back box section however this evening the exhaust broke, making contact with the road until I brought the car to a stop.  Needless to say it is beyond repair but has anyone else experienced failure of this type and infact has anyone had to replace their rear exhaust section yet due to age/corrosion?

It's a little odd as the other side is holding up far better and is what I would have expected the condition to be given a previous 5 series I had was still on it's original exhaust at 13 years and 130k miles?

I'm on 10 years and just over 100k with my GS currently.

[GSLV6]

I had something similar on my 2007 GS300, due to a design fault with the pipe where it split at the Y section and this was a point of high stress combined with insufficient support at that area.  It split, requiring a new exhaust at 69K miles.  Unsure if yours is a similar design but the only choice is to have a new exhaust supplied (and fitted by an indy to save money) or have a new S/S one made up (most on offer are quite hard, thin walled and prone to splitting though, unless you pay for a premium one which costs as much as the OEM one to have made up).

[pgg450h]

Thanks, sounds like that's exactly what has happened as the location is the same for the break.  The car is under Lexus warranty but I'm not sure how likely they will entertain a contribution but very annoyed at how suddenly it has failed.

Exploring the S/S route but appreciate your comments on their variable quality/cost and my concern is also if it could affect the remaining warranty I have.

Wasn't aware there might be Indy's who could supply and fit, thought it might have to be a dealer part?  Who did you use if you don't mind me asking and what did it cost?

 

[GSLV6]

I would advise that you push this as it should be covered by warranty.  The issue is widely recognised by Lexus on the Mk3 GS models and easy enough to prove it's not fair wear and tear by looking at the corrosion at the joint area,  As long as there is good steel left (and there ought to be as the originals were pretty solid and thick metal), and the split extends along the weld line, and around the Y junction, it is a stress fracture induced by cyclic fatigue due to insufficient support.  If you get no joy with a warranty claim, write to Lexus UK head office to the CEO and also to Lexus Japan, stating that it is a well know issue which ought to have been rectified on these models but wasn't.  Fact is, it's cheaper to attend to and honour the odd warranty claim than it would have been to redesign and re-manufacture a new part, hence you should get joy with a claim if you push hard enough.

The CAT back exhaust will cost you around £600 plus labour for fitting plus the VAT otherwise (from memory, I thing I got mine for £583 or something but then there's the fitting kit on top of that. How they expect you to buy an exhaust and not have a fitting kit with it is beyond me!).  Don't forget to have your chrome tail pipe ends removed.  These cost an arm and a leg from Lexus.  Insist on inspecting the old exhaust to prevent any charges for new chrome end pieces, as they're only retained with one bolt fixing and usually come off very easily.

Whilst there are no pattern pipes available for these, there are exhaust specialists who can make up stainless steel replacements, for the CAT back system.  The good ones should fit properly and be made of a decent gauge steel, but S/S is harder than the steel used for the OEM ones, and is more prone to cracking and stress fractures unless beefy enough, and few available are, at least under the cost of the OEM one.  I was advised by my local Indy not to go this route as he claimed that the standard one would last as long, would fit better and be quieter in operation as some after market ones dispense with the rear silencer boxes, or use inadequate ones which don't match the original.  I chose to pay for the standard pipe (£583) as mine was out of warranty and it didn't actually cost much more than having a good S/S one made up.  Forget the £200 to £300 SS pipe offers, they won't be up to the standards needed on gauge or strength and you'll be back having them welded up probably sooner than you'd like. 

[pgg450h]

The car is going in on Wednesday for an assessment, I'll be interested to see what options are presented.  The reason I have maintained the warranty and full Lexus history is to help avoid any unwelcome surprises, I do find it uncharacteristic that it has failed in this manner. 

Will post back with an update, thanks again for your suggestions and advice, it is much appreciated.

[messi]

Hi PPG450h

Im not sure where your based, but if your near Birmingham and you do want to go ss, I can highly recommend a place in Walsall called John Astley. No I dont work for them or anything like that, its just a recommendation, they did a brilliant job on my Sc430, I remember someone on here recommended them to us as the person had an issue with the exhaust on his mk3 Gs too.

[pgg450h]

Thanks Messi, will bear that in mind if it comes to considering s/s further as I live in Warwickshire so Walsall is not too far away. 

Plan 'a' though is to pursue a warranty fix.

[pgg450h]

Quoted £650 for replacement, claim submitted to Lexus warranty but dealer (who I have been very happy with) believes it will go nowhere..

[GSLV6]

That pricing sounds about right.  Make sure it includes the fitting kit though, and that the chrome tail sections are swapped over from old to new exhausts or that bill will rise quite sharply!  I found the invoices for mine.  The exhaust was about £583 and fitting was £72 = £657 all in.

[pgg450h]

My exhaust had infact snapped away at a different point than expected, it was right at the entry to the rear silencer on the driver's side.  There is actually a metal cradle of sorts which sits right beneath this point on both silencers, I'm not sure what they are for but you can see that is what hit the road and has been ground down.  If it wasn't for that barrier the results may have been more impactful with the potential for the silencer unit to be catapulted upwards and outwards if the edge itself had caught the road at the wrong angle.

Total bill was £650 all inc which is near enough what you had paid.  The warranty claim was rejected but I am going to pursue with Lexus Customer relations as the warranty is administered by TWG on behalf of Toyota/Lexus.  I have grown to like the car considerably over the years and bought into the brand values to the extent that I was only really considering another Lexus as a replacement but dependant upon how Lexus view this I may reconsider.

Yes it's a 10 year old car and corrosion is to be expected, indeed if both sides had corroded to similar extents then I would not have bothered mentioning it.  But the other side is in much better condition as has useful life still to give so the question would be what is 'normal corrosion / wear & tear' and what is considered abnormal/unusual/accelerated deterioration? I have never had a car do this before, I would have expected more warning signs e.g. a blowing exhaust to indicate is was that badly corroded - even my MOT garage who I trust fully hadn't raised the corrosion they could see as anything of concern.

 

[pgg450h]

[pgg450h]

Do you think I'm being unreasonable in expecting better from a Lexus?

[GSLV6]

That is unusual but my take on it is this:  The standard Lexus exhaust, compared with may after market-type replacements I've had over the years, seemed to be thicker and better made, therefore, I'd expect more life from it than from the usual mild steel offering.  However, 10 years would be what many regard as a reasonable life because there are so many variables to exhaust life.  It is mileage dependant as well as environment dependant, and the rate of external to internal corrosion will vary depending on both external environmental and internal conditions.  For the same given bore, as engine capacity rises, more moisture is produced per square cm of silencer end bore than for a smaller engine, and this also has to be borne in mind for internal environmental conditions.

Looking at the photos, it does seem that most of the corrosion is internal, causing a weakness that has resulted in a shear failure and a clean break.   If the car has regularly done shortish trips where the exhaust hasn't had the chance to heat up enough to burn off the water formed as part of the combustion cycle, and this has left the internal steel with a mixture of corrosive by-products of combustion, combined with a high moisture content, then 10 years would be a perfectly reasonable life for the exhaust.  I have had cars which have been on their original exhausts over 10 years, but few have made it much past that without needing a new back box, as the expansion chamber and the fact it's the end of the box mean it's the coolest part of the system and this is where most of the moisture will cause issues.

Even if the car has regularly done longer trips and had few short trips, 10 years, commensurate with mileage is also pretty reasonable for just a back box, although I'd expect one doing longer trips, but perhaps not daily, to last longer, up to 15 years or so for a Lexus system.

It looks like there's insufficient steel thickness to do a weld repair, so a new exhaust seems to be the only option.

Given that the car is 11 years old, I would doubt that even Lexus would see that as anything other than fair wear and tear.  The exhaust is a consumable, like tyres, just with a longer life-span.  

You may be able to get some sort of compromise, as I did with another claim on my GS, if you argue, that given the original quality of the exhaust, it seems unreasonable for it to break there after 11 years, but that you are willing to pay the parts price if they waive the fitting costs, as after all, they'll make that up and more if you stay on as a valued Lexus customer.  In my case, with my claim for TPMS valves, this is exactly what they did and I didn't have to pay labour for fitting or coding the valves which saved me over £100.

That's the best that I would expect tbh.

[pgg450h]

Thanks for the objective point of view, I was beginning to feel I was expecting too much from it. 10 years is a good life for a quality system and though the bulk of the mileage the car has done is c80+ miles of commute when it is in use the corrosion does appear to have eaten away from the inside so there must have been enough short trips to take their toll.

 

Thanks again for all your helpful advice and information.

[BarneyTT]

Sorry to hear of your exhaust woes....

Not sure if the GS450H exhaust is different from my GS430 (they look the same) but I was quoted by Lexus Bristol £800 for two rear back boxes, in fairness I haven't yet asked if that includes fitting. What did you get replaced for £650?

[pgg450h]

I had the back box section replaced. Starts off as a single pipe which connects to main exhaust then splits in a Y piece to feed each of the new silencers, it's all one assembly.  The original tips were re-used and the £650 I paid was fully fitted inc. vat.

[BarneyTT]

Many thanks for your reply. I have just spoken to Lexus Birmingham (ebay) and they have quoted me £429.43 which includes gaskets etc plus £25 p+p. Obviously I have fitting on top of that but my friend runs his own garage so I'm sure he would fit it for a reasonable price.

I have now queried my original quote of £800 with Lexus Bristol and I'm awaiting a call back.

Thanks again for your input.

[pgg450h]

That's the best price I've seen for a genuine back box so well done there, possibly Lexus Bristol were pricing for new tips too?

 

[BarneyTT]

I'm not sure how they arrived at the figure of £800 hence my query after the quote from Lexus Birmingham and reading your posts. Their quote may have included the tips but I'm wondering if that was including fitting, still expensive regardless. Lexus Bristol have always been very good with me so I'm hoping they come back with good news......watch this space!

[ISJason]

Hi PPG450h

Im not sure where your based, but if your near Birmingham and you do want to go ss, I can highly recommend a place in Walsall called John Astley. No I dont work for them or anything like that, its just a recommendation, they did a brilliant job on my Sc430, I remember someone on here recommended them to us as the person had an issue with the exhaust on his mk3 Gs too.

Just wondered if that John Astley is a Lexus independent. I'm in the West Midlands.

Sent from my iPad using Tapatalk

[messi]

Wouldnt it be cheaper and better going the ss route? I mean life time warranty and its alot better than what Lexus use

[pgg450h]

Personally, I just wanted to keep the car as quiet as possible, this replacement should see me out with the car so not too concerned by the warranty side. 

 

Appreciate the suggestion and I have done s/s on an old Honda CRX Vtec I used to have (loved that car) but it did make it a little noisier despite best efforts..

 

[messi]

You can have a quiet ss exhaust. 

[GSLV6]

8 hours ago, BarneyTT said:

I'm not sure how they arrived at the figure of £800 hence my query after the quote from Lexus Birmingham and reading your posts. Their quote may have included the tips but I'm wondering if that was including fitting, still expensive regardless. Lexus Bristol have always been very good with me so I'm hoping they come back with good news......watch this space!

That sounds like they have included the tips as the exhaust standard price (parts only)  is about £580.  Lexus Birmingham seem to give the cheapest price for just about any Lexus spare compared with the rest.

[Boddney]

I need a new cat back system on my 14 year old Mk2. Unfortunately the total fitted price for mine at Lexus is a whopping £1200. That's never gonna happen.

This is the best (well only) pattern part I can find on the planet that isn't S/S.

https://www.ebay.co.uk/itm/281960607686 

I think you guys with the Mk3 are lucky in this respect.

Bod.