Exhaust manifold Cup removal

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Tinkley
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Exhaust manifold Cup removal

Post by Tinkley » Thu Feb 11, 2016 8:53 am

The auto has decided to blow the exhaust gases past the conical wire gasket between the manifold and downpipe. The spring pressure was almost non existant as I could move the downpipe a lot by hand towards a proper clamp position. I've ground through the bolts OK as they refused to come undone with spanners, but can't seem to shift the two cups out of the manifold. They may never have been changed and she is nearly 25 years old... :wink:
Any tips how to get them out?. I may just slowly grind them out with a Dremel and angle grinder as you can't hit the cast iron much or it will give even more trouble.. :wink:

It's mainly the o/s one that is the problem as you can't get the new bolt in from above leaving the cup in place. Also not too willing to try removing the heat shield as I'm sure the bolts WILL shear. Even getting the old gasket off was a pain but it came eventually. BTW new exhaust bolt kit (3 different length bolts) from Peugeot a reasonable 13 quid and it seems the parts fit better than the last so called genuine one I got off 'tbay.

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Kitch
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Re: Exhaust manifold Cup removal

Post by Kitch » Thu Feb 11, 2016 10:05 am

Can't you just punch it out from underneath?

Tinkley
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Re: Exhaust manifold Cup removal

Post by Tinkley » Thu Feb 11, 2016 10:20 am

I might be able to, IF I could get underneath and she is on a downslope (nose down) so hard to chock. She may be a little loud starting hehe, but actually she was misfiring badly because of the leak at the gasket. Took at least 30 starts yesterday as she went through the awkward carb point till she went properly. From cold - first time but petered out after a couple of minutes, missing all the while. Can't bump an auto unfortunately... :wink: Once she was warm she ran OK just noisy, and the very odd miss. No one commented at the Pug dealers...

Yet to clean carb as this has probably never been done, but choke cuts in a bit late but eventually settles to correct idle. Not sure I have an option but to do this from above. Been spraying with release stuff so hopefully it might have some effect. Will get there one way or another.

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Jaba
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Re: Exhaust manifold Cup removal

Post by Jaba » Thu Feb 11, 2016 8:54 pm

They very often are rusted in place and need hammering out. It might help if you saw or grind through the exposed part in the manifold cutout then force the cut gap closed to reduce the cup's diameter. You could also remove the manifold to do it on the bench.
The Joy of BX with just one Citroën to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.

Tinkley
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Re: Exhaust manifold Cup removal

Post by Tinkley » Fri Feb 12, 2016 7:16 am

Thanks, they came out after grinding through the cup via the slot in the manifold (as you suggest Jaba) and this then released sufficient pressure to tap it out. A bit fiddly on the o/s as it's tight with a 115mm angle grinder if you value the heater hoses.... :wink:
Thank goodness for disimilar metals, the principle works in practice. BTW the genuine parts definitely fit better than the so called 'genuine' stuff on the bay where I had to really file the new cups down a lot to get them to fit. This one was a minute clean up with a round file in the cup holder part of the manifold and they tapped in sweet. It needs the longest of the three bolts which are as usual a bit of fun to get the nut started... :wink:

Having inspected the manifold nuts etc, I think I'd get a complete set of studs before attempting removal... :wink: There was almost no thread visible on the gasket bolts, so grinding/cutting was the correct thing to do. It did help putting a bit of release fluid around the cups as well. I would surmise the downpipe which looks good internally would have been changed once in the cars life. It was blowing around the entirity of the old gasket. My experience leads me to believe these (down) pipes last 15-17 years, much longer than back boxes. At least the rear part of the system is newish, though the rearmost hanger needs rewelding - the one bad (rusty) part of the car.

Finally back to the quiet sound she should be, an auto has to be at least dignified rather than like a go boy racer... :wink: