How long can the original exhaust last ?

[SeanR]

Anyone on a 2007 still with all original exhaust system ?, just curious.

[mk_lon]

Hey Sean, 

I got an 07 auto, with 88k on the clock. It's still got its original exhaust. It's been welded when a small hole appeared in the in the middle pipe in 2019 and currently smells of egg when I floor it in the cold but other than that it's fine. 

 

[Spark plug]

I think mine is original apart from new pipes welded in between the first and second cats. The egg smell is coming from the cats. I run mine on BP Super, use Red-x often, and never get the egg smell...

uer

[Vintagesixtysix]

Mines an 05 and started replacing sections two years ago….. so I guess the same time scale.

Lost a back box first & then the dreaded y section went next.

Finally replacing cats etc.

I had a custom stainless steel section made for the y to support it better…. Apart from that just went with mild steel replacement sections.

OEM is galvanised from factory rather than mild steel….. but I still think they have pretty remarkable longevity.

[T man 545645]

Im in an 06 just creeping up to 138k - fully original exhaust system.

[mk_lon]

18 hours ago, Spark plug said:

I think mine is original apart from new pipes welded in between the first and second cats. The egg smell is coming from the cats. I run mine on BP Super, use Red-x often, and never get the egg smell...

uer

Interesting.... I use shell v power but didn't know red x solves the problem. I thought it was the cats nearing end of life... Do you know why it happens and how often do you use red x? 

[Spark plug]

4 hours ago, mk_lon said:

Interesting.... I use shell v power but didn't know red x solves the problem. I thought it was the cats nearing end of life... Do you know why it happens and how often do you use red x? 

 

4 hours ago, mk_lon said:

Interesting.... I use shell v power but didn't know red x solves the problem. I thought it was the cats nearing end of life... Do you know why it happens and how often do you use red x? 

carbon build-up in the cats is what kills them when you do short runs and not warming the engine fully it causes unburnt fuel to reach the cats which causes damage as well.  Redx helps to clean the carbon away.

I use Redx every couple of months put a full 2 shot bottle in and fill up and go for a good fast run an Italian tuneup as it's called. I get the Redx in Tescos they often have it on offer its dear in other places 

[Andy_Ryan]

On 2/5/2024 at 5:44 AM, Vintagesixtysix said:

Mines an 05 and started replacing sections two years ago….. so I guess the same time scale.

Lost a back box first & then the dreaded y section went next.

Finally replacing cats etc.

I had a custom stainless steel section made for the y to support it better…. Apart from that just went with mild steel replacement sections.

OEM is galvanised from factory rather than mild steel….. but I still think they have pretty remarkable longevity.

Where did you get the parts from? I can’t find any anywhere.

[Vintagesixtysix]

Hi Andy,

Google…. Lexus IS 250 Exhaust should give you plenty of options.

My journey below….

Front section….

https://www.onlineautomotive.co.uk/car-parts/Lexus/IS250/2.5L/Petrol/Premium/Exhausts/Catalytic-Converters/LEX5005H/1/34?gad_source=1&gbraid=0AAAAAD9ghT5R5Th_Qf-P-Qtl9WfnSWRz3&gclid=Cj0KCQiAzoeuBhDqARIsAMdH14EPA5iCzfUZgNIUCJmP_NHRNobRVTfPpqbPKhho6OL2hh2jb3M-MxIaAqPbEALw_wcB
 

Rear section…….E-bay similar to this, fitting was very difficult to align properly.

https://www.cats2u.co.uk/lexus/37133-lexus-is250-25-rear-exhaust-box-silencer-08-05-03-13-ety784.html?gclid=Cj0KCQiAzoeuBhDqARIsAMdH14Fg2Xw-l6dn2JqO_Ollp3ClMXfwH_APb9wJlo2oHofR6SXnWdQaBr8aAh4lEALw_wcB

Custom made stainless section…..don’t be put off by the cherry bomb address. Jason and the team can fab anything you need.

https://www.cherrybomb.co.uk

 

….and when you’ve mulled over all this stuff, you’ll start the debate of cost & sound etc of going full stainless. 😁

KEEP Your original tips they just knock off….. they’ll clean up and keep you OEM look if that’s what you want.

Last time I looked they were £80/£90 each OEM to replace 🙄.

 

 

[Vintagesixtysix]

In addition….

if you’re diy-ing or local garage, I also sourced new spring bolts, doughnut gaskets and rear box hangers. 
( didn’t actually use the new hangers in the end as the original ones were/are still going strong)

hope helps

[2AD FHV]

Mine lasted from conception from 2009 to 2021. 

The rear silencer came off at 60mph and it kind of jack knifed under the car almost taking the bumper with it 🤨

[SeanR]

If the exhaust on mine does go then i don't want to be throwing lots of money into a replacement, just something that sounds the same and looks the same from the back end.

Just to get whatever time i have left with the car, not sure exactly how long that my be.

[Linas.P]

Really depends on how much and what kind of driving you are doing. If you doing a lot of miles and long trips, then your exhaust will be fine, if car sits for long times undriven and then does a short trip, then it will rot very quickly.

I would say - worst case scenario ~8 years, but some probably last 12 years or more.

[Vintagesixtysix]

I once had a random conversation with an old boy who’d worked at Jag all his career and he told me that the back boxes on the the V8s and V12s were always drilled at the lowest point with a X’mm hole from factory to drain the condensation.

Significantly increasing their life ( his words).

It did make me think as when I lost my back box…. I was really surprised…I must have poured a litre of liquid out of it even though I’d been driving for 15 mins at least…. Before chucking it in the boot.

Its been discussed lots of times that even when running hot how much condensation the exhaust seems to (smoke/steam) in the right cold weather conditions.

I levelled back at him that would be a bit of an MOT issue nowadays……

He said…Rubber grommets would sort that.

Just made me wonder…..???

 

[Linas.P]

I have seen holes drilled into the bottom of backbox. In theory anything after emissions equipment is legal, however it would throw the emissions measuring probe off and likely cause MOT failure on emissions.

[Thelongterm]

On 2/11/2024 at 12:29 PM, Linas.P said:

I have seen holes drilled into the bottom of backbox. In theory anything after emissions equipment is legal, however it would throw the emissions measuring probe off and likely cause MOT failure on emissions.

I experienced this issue with the overweight back boxes eventually rusting from the inside and then shearing off.

My driving pattern is short journeys from cold and a once-a-week roaring down the motorway,  so it is not exactly good for the muffler considering slow-to-heat-up v6 and those fat deep boxes.

Drain halls sound like a sensible idea for my new back boxes. So is it just a matter of plugging the hole with, say, a screw when you go down the MOT and then taking them out until the next year?

[Linas.P]

16 hours ago, Thelongterm said:

Drain halls sound like a sensible idea for my new back boxes. So is it just a matter of plugging the hole with, say, a screw when you go down the MOT and then taking them out until the next year?

That is exactly what I have seen done. It wasn't a screw, but more like small rubber plug. Ad as far as I understand it was factory job on some cars.

Also when I lost back box on my IS250 (at ~120k miles and 8 years old), it wasn't rusted, it just sheared off, looked like stress fracture. Got it welded back and it lasted another 70k+ miles after that (it never failed again, but car got stolen, so don't know how long it would have lasted). Also thinking about it - my old IS250 had it's all original exhaust by 200k miles, it looked rather horrible and rusty from outside, but there were no holes or any other issues apart of one backbox falling as mentioned. But I consider that car a little bit of outlier, high mileage and generally exhaust don't last that long.

[Thelongterm]

21 hours ago, Linas.P said:

That is exactly what I have seen done. It wasn't a screw, but more like small rubber plug. Ad as far as I understand it was factory job on some cars.

Also when I lost back box on my IS250 (at ~120k miles and 8 years old), it wasn't rusted, it just sheared off, looked like stress fracture. Got it welded back and it lasted another 70k+ miles after that (it never failed again, but car got stolen, so don't know how long it would have lasted). Also thinking about it - my old IS250 had it's all original exhaust by 200k miles, it looked rather horrible and rusty from outside, but there were no holes or any other issues apart of one backbox falling as mentioned. But I consider that car a little bit of outlier, high mileage and generally exhaust don't last that long.

Ok, I think I will get my cordless drill out.

Can you point out the most effective point to make these drain holes on the IS250 stock boxes?

Also, what diameter will these holes need to be? when you use a rubber bung in the MOT will the box not going to be hot enough to melt these?

[Ozzay]

Found an exhaust issue today. Was not intending to look for this issue but was looking at the clunking issue. At that backbox has a hole in there. Does anyone recommend I buy the unit (back box rear right) or can I just bandage this? I did wonder why my car sounded a bit louder than usual from the back.

 

[Linas.P]

13 hours ago, Thelongterm said:

Ok, I think I will get my cordless drill out.

Can you point out the most effective point to make these drain holes on the IS250 stock boxes?

Also, what diameter will these holes need to be? when you use a rubber bung in the MOT will the box not going to be hot enough to melt these?

You need to find the lowest point on the pipe, I assume that is going to be just under the rear axle. Anything after secondary cats should be fine.

No that rubber melts at ~200-280C, so it is very unlikely that any part of exhaust get's that hot after catalytic converter. 

What I have personally seen is the hole in the back silencer, however I am not sure how the internal layout on IS250 looks, so it is hard to say if hole in the box would achieve anything. Based on some comments above (water pouring out of the back box) it sound like it may work, but I am not 100% sure.

As for diameter - buy the rubber plugs first, measure their diameter and drill hole ~10% smaller than the plug e.g. say 6.5mm hole for 7mm plug.

[Vintagesixtysix]

On 2/15/2024 at 11:25 AM, Ozzay said:

Found an exhaust issue today. Was not intending to look for this issue but was looking at the clunking issue. At that backbox has a hole in there. Does anyone recommend I buy the unit (back box rear right) or can I just bandage this? I did wonder why my car sounded a bit louder than usual from the back.

 

Looks like you’re going to need a new rear section.

You may be able to bandage it temporarily to improve the sound if you’re not planning on replacing in the near future (& mot is not looming).

 

[Vintagesixtysix]

[MartinH]

My 07 is still on the original exhaust at 99,500 miles

[Mr Vlad]

I forget the mileage on my beloved is250 was but it was very close to 100k miles. It was an 07 car and was on its original exhaust system. It was even still in tact after I wrote it off with the rear end mullered. 

I suppose with exhaust systems it depends on how the car is used. Atmospheric conditions etc etc. Sometimes an owner is lucky and some others are not. Once a hole appears then sods law states more will appear sooner than later. No point patching as its wasted money and time.

[Thelongterm]

After my right back box had sheared off at 55k, I scrutinized it. There were no signs of rust outside, and a quick look at the connecting pipe where it sheared off showed nothing was building up internally in the box, only on the connecting bit, so I suppose these original systems were very robust indeed. 

The exhaust specialist checked the left box and noticed the same thing was developing there, too.

It may have been a weak point, I don't really know, considering these boxes are a bit overweight to start with. It may be that not a lot of rust is needed to bring it to a breaking point.

The replacement mild aluminium steel came at 3.5 kg less per box than the original back boxes. The kit came with the Y section, so I got those changes as well at the same time (see earlier thread).