Why does my exhaust manifold gasket keep blowing out?
Exhaust manifold gaskets fail repeatedly because corrosion pitting on the engine cylinder head creates micro-gaps that no gasket can seal long-term. This continuous leakage prevents the exhaust system from holding pressure and forces constant gasket replacements.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 12.7× more often in r/MechanicAdvice than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1doubling up the gasketsDid this help you?
- 2using a thin smear of high temp copper rtv on the head sideDid this help you?
- 3Cutting the nipple down and threading a brass fitting with JB WeldDid this help you?
- 4Replacing the entire intake manifoldDid this help you?
- 5applying cerkote or high temp exhaust coatingDid this help you?
- 6wrapping the manifold in fiberglass exhaust wrapDid this help you?
- 7applying 2stroke engine oil when hotDid this help you?
- 8punching out the studs and using standard bolts and nutsDid this help you?
- 9taking the car to a professional muffler shopDid this help you?
- 10Using fine grit paper or emery cloth with a block or bolt to smooth and flatten the surfaceDid this help you?
- 11Resurfacing with a stoneDid this help you?
- 12Annealing reused copper washers with a blowtorch and seating them with a hammerDid this help you?
- 13Switching to a rubber bonded or alternative washer sealDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Hi all, my Invidia R400 cat back exhaust I believe separated at the mid pipe. It’s a Subaru wrx 2017 Va potential fix?”source ↗
“Trying to determine the best way to fix this broken connection on a nipple coming out of the intake manifold of our 2024 Ford Maverick 2.0L all gas engine.”source ↗
“I can’t seem to find any videos or guides on this sort of fix or replacement”source ↗
“I can barely see or reach this space with my hand right now”source ↗
“I can’t find any concrete info on what this port even is, how much pressure it is under, or how vital a pure and solid connection is to the functioning of the vehicle.”source ↗
“Have a slight problem with exhaust header/manifold gasket blowing on my nissan 300c”source ↗
“after a while the gasket is blowing again”source ↗
“the corrosion pitting is the root of your problem no gasket will seal that long term”source ↗
“I’m not sure why I would’ve used it on this mating surface but there appears to be gouges likely from the wire brush.”source ↗
“A banjo bolt threads here with a copper washer and gas slowly leaking.”source ↗
“Difficult to say how to repair it, it needs to be perfectly flat across itself.”source ↗
“I can see bubbles forming from this surface though.”source ↗
“Was thinking about trying to polish it, but am unsure if its too far gone.”source ↗
Where this came up
People with this problem also raised
- 4Can you use RTV silicone to patch a hole in a timing belt cover?
- 2Will a scratched gasket surface still seal?
- 15How to fix a leaking exhaust pipe with wrap on it
- 3Gasket coating chipping off during cleaning
- 3Can you use JB Weld on a cut sway bar or metal car part?
- 4Stripped oil pan drain plug threads won't tighten or spin