Exhaust leak

[deejay1272]

As I was piecing the Terjunken together the other day after finishing my timing belt, t-stat, water pump R&R job, I noticed a puff of exhaust smoke billowing out from the engine compartment when I blipped the throttle. Originally I thought this was due to loose connections at the exhaust manifold (which I recently addressed - damn it's hard to reach all those bolts!).

Now I've tracked the problem down to the connection between the exhaust down pipe and the manifold. Here's the best photo that I have to show what I'm talking about:


Is it common for these connections to simply get loose and require a bit of re-torquing OR should I consider getting a new gasket or other part to remedy this problem?

Also, I imagine that this is rather dangerous having exhaust leaking into the engine bay where it can enter the cabin (CO can be pretty insidious stuff). Can this also contribute to reduced fuel economy?

[dlb]

new gasket time. it's often called a donut. i've been meaning to get to the same job on my wife's truck. don't know about the economy but i know i had a 15-passenger dodge van (band touring vehicle) and when the exhaust came apart the vehicle lost a LOT of low-end torque. depends how bad your leak is though, in that case the exhaust connections broke clean apart.

[xirdneh]

A few years ago i was driving home from work and woke up when i heard the tires hit gravel and i was headed into a swamp at 55 mph
i managed to get out of it (barely)
but felt sick that evening
it was that donut gasket that your going to need to replace
it was not leaking much but i could feel a little air coming out and it had an effect

[dlb]

A few years ago i was driving home from work and woke up when i heard the tires hit gravel and i was headed into a swamp at 55 mph
i managed to get out of it (barely)
but felt sick that evening
it was that donut gasket that your going to need to replace
it was not leaking much but i could feel a little air coming out and it had an effect

holy shit, at first i thought you were just telling a funny, unrelated anecdote. that's actually terrifying to think you not only almost crashed but were also suffocating. brutal.

[deejay1272]

mmm, donut.

[Petros]

They usually go bad, easy fix once you get the nuts broke loose (the worst part sometimes) Put AFT on the nuts and let is sit overnight (AFT makes the BEST penetrating oil). You can do it either from under or over, if it is really stuck you will need a 14mm deep socket, 16" of extensions and a big breaker bar. Make sure the socket is well seated on the nut or you will bung up the flats so bad you will make it very difficult to remove the nut. If you do it from the top, remove the charcoal canister to give you access, put a 14 mm box end wrench on it and tap it with a hammer to break it loose. I have had to chisel the nut off before when some previous mechanic has already stripped off the flats for me.

The ring gasket is cheap, about $4 last time I bought one, just be careful when reinstalling it so it stays in place and you do not crush it all misaligned, it will leak for sure than. I have been using high temp RTV to hold it in place to make sure it stays put while you fight the head pipe back onto the exhaust manifold studs.

[deejay1272]

Thanks for the tips, y'all. I'll get to this one sooner rather than later so as to not get CO poisoning and make myself any dumber.