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The engine exhaust control valve on my 4.9L (300 CID) engine came loose and I pulled it out. Now there is a hole where the valve was and the truck sounds like it has a big hole in the muffler. Kind of annoying to say the least. Is it fixable without having to buy another manifold or tearing into the engine? The figure in the manual looks like the valve is welded on the inside. I'd hate to have take everything apart. One guy said I could plug it with a piece of wood dowl. Any suggestions?
No it's not vital. It's intended to help with cold starting. I think it increases the back pressure to increase the heat for your choke or something along those lines. You could tap it for a bolt or even just stuff some JB weld in there. I was working on my friends van the other day and noticed someone had tack welded that valve open.
It does force exhaust back up underneath the carb to warm it up quicker. If you keep the pipe going to the air cleaner snorkel from the exhaust, that usually covers up any problems with taking the exhaust valve out. If you have neither one, expect some trouble in cold weather.
I didn't have a tap, so instead I installed a soft plug in the hole. It seems to have taken care of the problem. I don't know if the soft plug will last, but I sure hope it does. You guys are great!