I removed the exhaust manifold on my vehicle and now I am using a new gasket for the new headers. My question is how do I clean the block around the exhaust ports without damaging my engine? can I just spray a degreaser or would that damage my exhaust valves?

enter image description here

Second question is I think the gasket on the catalytic convert is baked on there because it did not drop after removing the manifold how can I remove the old one?

1 Answer 1


If the manifold studs come out easily enough that would make the gasket cleaning job easier, however they're usually a bit stubborn to remove so working around them is better than risking damaging the threads etc if they're tight. You can carefully use a razor/scraper blade etc to remove the old gasket remains.. But go slowly and don't dig into the cylinder head as its only aluminium. If there are any really stubborn areas you can use brake cleaner to help remove them. Or even a tiny smear of engine oil left to soak in for half an hour or so can help soften baked gasket material. Just remember to clean it off properly with brake cleaner when you're done.

You should be able to get the catalytic converter gasket off just using a scraper blade too. They normally come off in one piece if you carfully get the razor/scraper blade underneath it.

  • Should I be worried at all from brake cleaner getting into the valves and damaging them
    – method
    Feb 4, 2017 at 7:39
  • 1
    No need to worry at all.. Brake cleaner will not harm the valves. More importantly though, even though they're exhaust ports is to make sure that no bits of gasket etc end up in there. So before you start the job just push a bit of lint-free cloth or a loose ball of masking tape etc into each port to help prevent that. No need to cram it in there tight either, just enough so that the port is not totally open to any loose flying bits of gasket.
    – Orb
    Feb 4, 2017 at 9:23

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .