I went into the disassembly of the exhaust with much trepidation.
The 74’s AH engine disassembly was a nightmare with so much exhaust nut and bolt corrosion and not to mention the degradation of the tin connections to the heat exchangers.
The 72’s AE engine break down was pretty much the same.
EGR System Removal
I started with the EGR valve remove up top since I needed to free up that space to remove deeper items. It was al pretty straight-foward.
It is interesting that the base of the pipe actually is mounted through the pulley tin to bolts on a filter below the engine and not by bolts in and of itself.
When a previous owner removed it all, they cut the filter below then crimped this up so the pipe would still be mounted.
There are so many EGR gaskets to the full system and gas path.
I think I counted 13 total from throttle body all the way to the final gasket at the muffler. At $5-$8 per gasket that is pretty expensive.
I’m tempted to reuse some of these but it kind of defeats the purpose of restoring as much to new as possible, especially where gasket and mating surfaces are concerned.
It all came off very easy, but I could not remove the final piper from the valve to the throttle body until the fan shroud came off.
Exhaust System Removal
Now I sprayed penetrating oil on all the bolts and nuts and let it sit for some time.
I really prefer this heavy metal with the flanges using bolts and nuts to the clamps with some kind of high-temp material sealing the connections.
While I did have to use some force to get bolts moving, all of this came out far easier than I expected without anything breaking or getting damaged.
I just went bolt to bolt and nut to nut trying my best to not break anything or damage anything.
The only problem is something I uncovered and is not exactly something I caused.
The one heat exchanger came off and it was immediately apparent that the mount point on the tin was broken off on it. I was not thrilled, but at least I did not cause it.
Heating up the screw (and subsequent grime) removed it. Previous engine exhaust disassembly was always a nightmare of stirpped screws or things that would not budge.
After all of the main stuff was off, I focused on the muffler.
The bit where they cut the EGR extension pipe and crimped it came off easily.
I really figured that the tail pipe clamp would be the worst but it wasn’t it all came off.
The material gasket that the clamp seals the pipe onto the muffler was the hardest thing to get off as I essentially had to use an screwdriver and happen to break it then push it off.
While the original tail pipe is of course far better quality than the aftermarket ones (look at the thickness above), you can see how it scrapes going up the driveway. We have quite an extreme angle to the street and it is almost impossible to not scrape.
I think I will treat these as disposable. I’ll manually remove the rust from the original and try to bang that dent out and then paint it.
However, I’ll install the aftermarket one that I’ll paint as on the car and if it scrapes I won’t be messing up an original part.
Now the entire exhaust system (sans EGR part) uses 2 different types of gaskets.
The heads use what appears to be the same old school metal gaskets that always ship with engine kits. At least they feel like metal… just corroded compared to a new one.
The connections between the exhaust manifold pipe to the 2nd pipe, and then the 2nd pipe to the heat exchanger is basically a larger version of the head exhaust gasket. I think they are metal as well.
Honestly, there’s so much age on them that they feel like they could be a brittle metal or an aged fiber.
With the exception of the surface corrosion, everything seems to be solid and I do not believe I will need to seek any welding repairs on the exhaust prior to ceramic powder coating.
I removed the small damaged bit of tin and may pursue, if I can find someone, who can weld that bit back to the tin prior to restoring them.
The EGR pipes all seem clean, and while they all need multiple gaskets, I think everything is sound. I am assuming the valve itself is sound and functional. At least I hope so. I will try to research how to test it. I mean, there’s no point in reinstalling a fully working EGR system from throttle body to exhaust if the valve itself is no longer functional.
I’m not sure if I’ll powder coat the intake manifolds or not. Since they are not exposed to the elements, I have never really seen any in horrible condition and Murbella’s are fine, though they need cleaning and possibly a painting or a top coat.
Then again, these are manifolds I just can’t easily get my hands on. Powder coating may give them a much longer life. I doubt it though. At least while I’m her caretaker.