Exhaust leak or normal?

[Czar1500]

This looks like an exhaust leak to me but not entirely sure?

I get a subtle pop/backfire when deaccelerating while still in gear. Wondering if that is related or if it’s normal as well?

Thanks for the wealth of information. I don’t think I would be able to keep this car running without you guys!

[KTPhil]

You are missing a clamp/seal where the sheet metal jacket meets the exhaust pipe. They seem to be NLA, so here is a workaround:

New seals are somewhat known for not sealing well. And the leak will force exhaust gases into your heat exchanger fresh air supply. Pressure from the exhaust leak "jet" is greater than air pressure in the heater system, and it shoots it right into the heater air flow, a CO danger. Plus it stinks.

I used a non-hardening muffler sealant on the HE pipe to bridge the gaps between the rough HE pipe and the donut seal. Smooth it on, and put an excess so the donut squishes into it even without the clamp, then clamp as usual (and clean up the excess). With the goop, you don't have to crank the claps so tightly that it bends the plate and leaks.

I also took Jim Adney's suggestion to make strips of folded aluminum foil into a wrap around the HE pipe where it meets the HE metal jacket, which is where the exhaust leaks can force their way into the heater. The original clamps go here, but mine were missing:

I held them in place with a large worm clamp. No more fumes!

[Czar1500]

I’ll give that a try. Thanks for the detailed write up.

[Multi69s]

KT,

How is your oil temp when driving slow around town? I had a similar oil setup on my Type 1 and it was kind of high. Got some exhaust wrap and it dropped twenty degrees in town, freeway wasn't that big of a difference.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[KTPhil]

It runs hot at high rpm oin the freeway, not so bad around town. I'm still sleuthing the highway heat gremlins, and when all done, I may either make a sheet metal shield or look for some wrap. Bigger fish to fry right now!