MOT prep time - exhaust bits corroded and what else to check

Leon1davies · 24 Sep 2016

So MOT is coming up and one of the jobs I've been meaning to do for a while is sort out the corroded exhaust nuts and bolts...not sure if they're a failure or not but every time the car is inspected it's mentioned so thought it's best to do it.

There's a lot of corrosion, to the point the nuts are barely existent, on the tail pipe clamp, the cat to muffler bracket clamp, the cat clamp and the cat to headers flange (so everything).

To tackle this job am I best to take the mufflers and cats off the car or just the mufflers or should I leave it all on and try cut everything off?

The bracket clamp connecting the cats to the mufflers is the bit I don't know how to replace without doing that. The cat to headers flange I can clean up, pack with washers and get a nut on the end (not pretty but does the job). Just looking for the easiest way but also want to make sure I do a decent job that won't need repeating.

deMort · 24 Sep 2016

Im not sure how i would do it in the garage will really help , ill explain if needed but best i think if someone with experience of doing it on stands could answer .

For MOT as long as no major exhaust blows or obvious missing fixings then it should be fine .

wasz · 24 Sep 2016

Don't bother unless the exhaust is blowing from the join. The bolts will still do there jobs when they rust to blobs.

You are entering a world of pain.

I had to cut all mine off (inc the lower of the 3 muffler to engine bracket nuts).

Leon1davies · 24 Sep 2016

Yeah one of the reasons I've put this off for so long is I have a feeling it's going to be a pain! If it isn't going to cause issues on the MOT I'll leave it for now...exhaust is fine, no leeks etc. Will take it in somewhere to have it done properly by someone who knows what they're doing lol

cheshire911 · 25 Sep 2016

Good decision! If it ain't blowing, leave well alone.
It can be a devil of a job and may require specialist tools and require extraordinary labour time - I've heard stories in some cases of 8 hours labour!

Things break and snap. Access without a ramp is challenging.
An attempt on axle stands on the drive can end up with it being flat-bed trailered to an Indy to pick up the mess.

Bit I'll say one thing, nice new shiny nuts look impressive and show a buyer that an owner was proactive on spend for the car!

Edit: You asked what else to check. I'd suggest brake pipes and discs (especially rear discs for corrosion)

deMort · 25 Sep 2016

Assumeing you dont need the exhaust mainifolds removeing and unless they are blowing then i really wouldn,t then replaceing flange bolts and clamps is a 3 hour job .

NOT a job i would want to do on stands thats for sure .

Palladium · 25 Sep 2016

leave well alone.

Dave67 · 25 Sep 2016

Oh *****,I have no choice as I've got a blow on one of the cat to manifold flanged joints.

Going to take the opportunity to fit some 200 cell X pipe sport cats to ease the pain....

Dave67 · 25 Sep 2016

Oh *****,I have no choice as I've got a blow on one of the cat to manifold flanged joints.

Going to take the opportunity to fit some 200 cell X pipe sport cats to ease the pain....

Leon1davies · 25 Sep 2016

Dave67 said:
Oh *****,I have no choice as I've got a blow on one of the cat to manifold flanged joints.

Going to take the opportunity to fit some 200 cell X pipe sport cats to ease the pain....

I had the same issue a few months back and my local welder managed to clean the studs up, pack them with washers and get a nut on the remaining thread...not sure if this'll work in your case until you get the 200 cells

Ian1978 · 26 Sep 2016

I have the same issue with my cat to manifold bolts, I have got some A4 stainless replacements to try and stop it happening again.

The top nut on both sides has pretty much gone.

I have recently replaced my back boxes so a bit of an easier job to do for me but it is worth noting that if you need your spark plugs replacing then you will need to remove the back boxes anyway, so my local OPC informed me, they also said that this can be costly if they have to spend more time cutting off and replacing the old ones, so well worth thinking about.

Dave67 · 26 Sep 2016

I replaced the back boxes quite recently so I've got bit of a head start.

I'll make sure I have everything to hand before I start.Sounds like I should replace the plugs whilst I'm about it?

Was thinking of changing the manifolds at the same time,is it worth it? What benefits if any,would there be?

All the ones I have seen, say " not suitable for tiptronic "??

wasz · 26 Sep 2016

Dave67 said:
Was thinking of changing the manifolds at the same time,is it worth it? What benefits if any,would there be?

Be prepared for many hours drilling with a jig.

Or leave it until it blows and pay someone else to do it (with a jig).

Ian1978 · 26 Sep 2016

Yeah, manifolds is one on my list, but to be honest the look of the bolts says stay clear until a) I have to and b) funds allow for me to pay someone to do it properly with the right equipment

Dave67 · 26 Sep 2016

wasz said:
Dave67 said:

Was thinking of changing the manifolds at the same time,is it worth it? What benefits if any,would there be?

Click to expand...

Be prepared for many hours drilling with a jig.

Or leave it until it blows and pay someone else to do it (with a jig).

I'll leave it be then.

MOT prep time - exhaust bits corroded and what else to check

Leon1davies

Hockenheim

deMort

Monaco

wasz

Paul Ricard

Leon1davies

Hockenheim

cheshire911

Portimao

deMort

Monaco

Palladium

Indianapolis

Dave67

Trainee

Dave67

Trainee

Leon1davies

Hockenheim

Ian1978

Trainee

Dave67

Trainee

wasz

Paul Ricard

Ian1978

Trainee

Dave67

Trainee

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