Doubling up on exhaust gaskets

[blackglasspirate]

Hey all,

Is doubling up on exhaust manifold gaskets a good idea or no?

I noticed the other that I had a small exhaust leak at the header flange at the #2 cylinder. I could see a gap between the gasket and the engine and figured something might have come loose and the exhaust ate away part of the gasket (which was recently replaced). Well I went in there today to replace it and the gasket is fine and there's a gap with the new one as well. Seems like the header isn't sitting flush with the engine and I can't figure out why. I loosened all of the connections on that header, tried moving it around and tightening that flange first but still no go. As a temporary measure I doubled up on the gaskets. It still leaks a tiny bit (at least, when cold, maybe the expansion on warm-up will seal it up), but it'll do until I can get in there and investigate more next week. I just wasn't sure if doubling up was a common thing to do or a bad idea.

New seal, you can see the gap still and where it had been leaking before:

With two gaskets it seems to be leaking from between the two gaskets:

The old gasket. It was leaking between the metal part and the engine:

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'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[ALIKA T3]

Your exhaust flange is not straight or your head is pitted ( brah!)

Gotta make one or the other flat again....
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[PDXWesty]

Face the gaskets the same way so that the softer part does the sealing?
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89 Westy 2.1 Auto

[Gauche1968]

Metal side of the gasket is supposed to face the head. Are you sure its the gaskets leaking? Is that a possible pin hole on the pipe near the nuts?
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1984 Vanagon GL
1984 Vanagon Westy

[Wildthings]

Pull the pipe and place a straight edge across the flange. You will probably find that the ears have been bent a bit. Use a angle grinder or dremel to grind down any high spots.

Alternately, you might be able to go a long time by using JB Weld as a filler between the two gaskets. No promises.

[campism]

I have belt-sanded exhaust pipe flanges to make them flatter for a better seal, and used double gaskets. I also heavily gunked all mating surfaces (flanges, head, both sides of each gasket) with Permatex Copper Spray-A-Gasket. Good luck!

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'87 Westy in Wolfram Grey Metallic

[Butcher]

[blackglasspirate]

[campism]

I had a similar leak on the same cylinder and I put a stainless hose clamp around the flange/head juncture. It fits pretty well and does not repair the leak but it does help muffle it a bit if you find the noise distracting.
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'87 Westy in Wolfram Grey Metallic

[blackglasspirate]

[blackglasspirate]

Well, turns out I can't use the soapy water trick when it's warmed up because it all sizzles/bubbles so much on the hot metal that I can't tell if air out of the leak is causing any of bubbles. Oh well. I'm going to take it off again tomorrow and see what I can do.
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[PDXWesty]

I would try them with both metal sides facing the head. That will give the softer side a chance to seal against the header as if you were only using a single gasket.
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89 Westy 2.1 Auto

[blackglasspirate]

Thanks, that's a good idea. I'll give that a shot when I look at it tomorrow.
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[IdahoDoug]

FYI, frustrated at poor joints at the cast iron Y, I tried doubling, and I tried NAPA's pricey exhaust joint goop to no avail. It just kept leaking. Finally, I took the parts to a buddy's machine shop and belt sanded them all flat. After my first 350 mile trip with the rebuilt engine and carefully tended to exhaust, I arrived home to a telltale pffft pfffft. Yep, something else is leaking under there I have no doubt. So it's a process with essentially no solution, apparently...

Doug
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[amwaj]

using a torque wrench to proper torque values during the initial install will avoid warped flanges...so if you manage to "unwarp" them, then replace the nuts, and studs and torque to proper values...unfortunately exhaust (and other) parts are usually over tightened, causing distortion to occur when the parts are heated due to dissimilar metal expansion rates...good luck, I wound up replacing all the exhaust and studs..(the studs weren't very cooperative)...
and then the retorque after 1000 miles and have had no more issues
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the best way to make a small fortune in life, is to start with a big one, and become afflicted with Vanagon-itis

[Wildthings]

Embossed metal gaskets will do a better job if the flanges are not flat than the composite gaskets you have. Doubling up of embossed gaskets seem to work particularly well in some cases.

[blackglasspirate]

[blackglasspirate]

Alright, well I made a valiant effort with doubled gaskets and the sealant. Tested it today and it appears there may still be a small leak, though not as bad. When I first started it up yesterday it definitely sounded loud like it had a big leak, but I think it may have been either really noisy lifters or something else from not running for a couple of days. I started it up this afternoon after sitting overnight and it sounds normal.

It's really hard to tell if the leak is there with the soapy liquid method because it always sizzles and bubbles up anyway from the hot metal, but I think it was bubbling more from around the gasket. It's small enough to where I can't feel any air coming out if I put my hand there, so I doubt it's going to cause any issues.

Maybe the solution is to overtighten the nuts/studs and hope it warps back into shape
_________________
'87 Vanagon GL Westfalia
IG: @holidayatsee
FB: https://www.facebook.com/holidayatsee

[ALIKA T3]

[blackglasspirate]