Exhaust fun and games

The rear silencer fell off my D1 V8 recently, which made me think it was about time i gave the exhaust some attention. £300 lighter, I had a replacement after market full system on it's way.

When i collected it from the garage that supplies the parts and also fits them, I was warned about replacing the downpipes on my own at home. Apparently the huge amount of heat generated by the v8 lump causes the exhaust sections to weld together, and i was warned that they normally struggle when using full workshop facilities of a 4 post ramp and oxy torch and so working at ground level without a torch was not recommended.

I took the advice, and changed the centre and rear sections myself, and booked in to have the downpipe fitted.

This is where the fun starts. They called back after an initial inspection, saying they couldn't do the work. The lambda sensors are both heavily corroded and welded to the pipes, they didn't want to risk removing them and breaking them. Next, the studs connecting the downpipes to the manifold cant be removed for the same reason, and given the location of one of the studs they can't drill them out and replace them with bolts.
Finally, someone has tried to remove one of the inlet maifolds before, and snapped off the bolt.

In summary, to fit the rest of the system they want to cut the downpipes off, remove the head to then drill out and tap the broken bolt, which they would have done by an engineering company as they won't do this in house. Excluding parts they said i'm looking at £1500.

Do you think this sounds about right, or excessive?

you need to find a garage that knows what there doing , it's not a fun clean job , but fook it's not that bad , and , your paying them .!!!!!!!:5brant: having done this job for too long at an independent landy dealer , I would suggest they dont like hard work .

Removing the manifold from the head maybe but having to remove the head? I can understand the problems with the lambda sensors.

Why are u replacing the Y pipe and cats, do they need replacing? when my tail pipe failed I just replaced with a cat back system only 30mins work.

My manifold to Y pipe nuts undo ok, last year when the pipe was droped to have the auto box filter change, no doubt with the help of a spray Plusgas fluid undoing the nuts is all that's required as the joints are flanged so not a pipe slidding into another method that do weld together..

discool said:

Removing the manifold from the head maybe but having to remove the head? I can understand the problems with the lambda sensors.

Why are u replacing the Y pipe and cats, do they need replacing? when my tail pipe failed I just rplaced with a cat back system only 30mins work.

My manifold to Y pipe nuts undo ok, last year when the pipe was droped to have the auto box filter change, no doubt with the help of a spray Plusgas fluid undoing the nuts is all that's required as the joints are flanged so not a pipe slidding into another method that do weld together..

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They said the head has to come off a) to get sufficent clearance to drill and tap the manifold bolt that sheared inside the head and b) because they have to send it away to do rather than doing it in house.

Initially i was going to just do the rear section, butt hen i saw the service schedule on the cat, and mine has done 127k so thought worth doing at the same time. Problem is I had to cut the old centre section off the rear section to remove it, and the joint between the OEM downpipe and after market centre doesn't allign fully (it does allign when connected to after market downpipe) and now blows!

The original cat back pipe must have been the original then as they are one piece.
If you don't want to DIY i'm sure you can find a garage or home mechanic to do the job for a lot lot less than £1500 +.

The flange should be square on, then may be u could adjust the exhaust mounts some how for s better fit.

Thanks for the tips, im more than happy to give it a go myself to save that much cash! I just dont have the kit to tap the head to manifold bolt.

Regarding the manifold to downpipe, any tips for getting the bolts free? I have heard heat helps, I dont have an oxy torch but would I get similar results if I get the engine up to temp and jump in (with thick leather gloves!!)?

twinter82 said:

Regarding the manifold to downpipe, any tips for getting the bolts free? I have heard heat helps, I dont have an oxy torch but would I get similar results if I get the engine up to temp first?

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Any views appreciated chaps! Obviously not going to happen with the snow, but good to know for next weekend.