MOT failed emmission, whole in exhaust

[Beno148]

Hi all,

Mrs mini 56 plate 1.6 petrol has failed its MOT, couple anti roll bars which hopefully be easy enough.

Failed emissions and MOT tester suggested it was due to whole in exhaust and he could weld some metal and should then be fine. Had a mobile mechanic account and he said because of the subframe to access advised just to put a new exhaust in.

Anyone had experience or got any advice? Ill also attach MOT paperwork

TIA

Ben

Edited by Beno148 on Monday 28th October 08:44

[soad]

Can’t attach photos as a new poster, just saying.

[Beno148]

ahhhh ok that makes things more difficult lol!

So the fail points are Exhaust Lamda reading after 2nd test idle outside specified limits.

Looking at the print out the only thing outside the limits is fast idle test lamda is readin 1.05 1st test 2nd test 1.04

TIA

Ben

[droopsnoot]

If there's a hole in the exhaust, wouldn't it also fail on that? "Exhaust system has a major leak or is insecure - Major".

If access is a problem and you'd prefer not to replace the system, could you put a sleeve around it?

[Beno148]

So the other MOT fail point linked to exhaust is exhaust issues likely to be affected by an exhaust leak (over rear subframe)

Going to get under it today and see if i can the hole and access.

TIA

Ben

[Davie]

Beno148 said:

due to whole in exhaust and he could weld some metal and should then be fine. Had a mobile mechanic account and he said because of the subframe to access advised just to put a new exhaust in.

No experience of a Mini, however...

If mechanic A said he could weld a patch on but you took to mechanic B who said otherwise... you could go back to mechanic A?

However, if mechanic B is correct and access to repair is hampered by the subframe thus it becomes a more labour intensive task to make the area accessible, then you're welding an exhaust that given the rust, has probably seen better days thus welding may not last or may not even work (you can't weld to rust) therefore it makes more sense to replace the part, more so when pattern parts are probably relatively inexpensive.

And yes, a major exhaust leak will fail... and also fail as the emissions exiting the tail pipe (where the tester is positioned) aren't correct as the emissions are exiting somewhere above the subframe. But that's assuming there's not a secondary issue with the emissions currently being masked by the holed exhaust - so fix / replace the exhaust, then retest it and then take it from there.

[Limpet]

Is it bodgeable?

Where there's been a leak in a pipe rather than a silencer, I've had success in the past by cutting the ends off a drinks can, cutting a lengthways slot, and then with a smear of Gun Gum (if that's still a thing) around the hole, wrap the can tightly around the pipe and secure it at either end with a couple of exhaust clamps. You can rotate the clamps to whatever orientation gives you the best access to the bolts. It's not pretty, but it's effective, and won't fail an MOT if it doesn't leak.

I've never found a satisfactory way of repairing silencers that doesn't involve welding. The proprietary bandage repairs are a complete waste of time and money in my experience.

Edited by Limpet on Monday 28th October 09:44

[Oilchange]

Exactly, Tin snips, a baked bean can/coke can, some exhaust putty and two jubliee clips for a temporary fix. Even a silencer can be repaired without welding with a little ingenuity.

Its not rocket science, any mechanic can get you through with half an hours work

Edited by Oilchange on Monday 28th October 10:10

[droopsnoot]

Maybe one for this thread: https://www.pistonheads.com/gassing/topic.asp?h=0&...

[paintman]

Fix the hole or replace the relevant part of the exhaust to stop any leaks & resubmit.
Been there done that & - so far! - never had an issue on resubmission.

[Beno148]

Thanks for all the replies. Been unable to reply back due to being a newbie and aint spam lol!

So i went out and got some holt exhaust bits, got a metal section round the hole with gum gum on inside. Also exhaust taped where it bended over the metal clip.

So far seems to be hardening, bit when run car idle some drips frpm the gum gum, is that normal? Retest later tonight, got some cataclean to run through abd give it a blast to get it through and all warmed up before.

TiA

Ben

[VeeReihenmotor6]

If you have some drips through the holts gum stuff then there is still an exhaust leak. You might be lucky and get a pass as most of the hole has been plugged.

Best bet, if you're wanting to keep the car and get a pass next year would be to replace the exhaust section. Even welding the exhaust won't give you long lasting results and imo is waste of time.

[Oilchange]

It will buy you a year on the mot so not really a waste, more like buying time

[RR76]

Just went through this. If the hole is in the flexi section you can just cut it out and buy a clamp on flexi section cost me £13 for flexi + paste + clamps.

[Beno148]

Good news its passed. So the paste and fittings and/or cataclean made the diff.

Thanks for all the replies and advice. Glad for the help.

Thank you

Ben

[richhead]

Pleased it has worked for the mot, but its really kicking the can down the road, sometimes this is needed, but it will need to be changed at some point, rust doesnt go away. So budget for a new exhaust.

[Beno148]

Yeh i know that its only a temp fix. Just gives us some time now through its mot.

Thank you

Ben