Blocked muffler/ No muffler

[mtruckr]

There just seems to be 'something' holding back the truck... we're thinking it may be a blocked muffler passage. It might be original ('69 3/4 ton), and we get a nice blast of black from the pipe when it gets revved in 'park'. It's a 305 V6, so just one pipe. (We are aware of the limitations on that motor. )
Other aspects have been tended to... it's been on the road for a year. Starts and runs fine...

I'm thinking of simply removing the muffler (just the muffler) and running it for a few days with nothing... is that unreasonable? Is it gonna be THAT loud?

Thanks-

[TheSeeker]

A few years ago someone cut the cat and muffler off my 94 toyota pickup. It was LOUD with the open pipe down there and it was a tiny little motor. I imagine you will be waking neighbors and getting the ol red n blues attention with out anything under that truck. Wish I could help with your problem though. Is it burning oil at all?

[cdowns]

back in the day some exhaust systems were made with double wall tubing and the interior part of the tubing would collapse causing a restriction the out side would give no indication of a problem

[Longhorn Man]

A pl. blast of black from the pipe means too much fuel. Try giving it a good tune before hacking up the pipe. If it was clogged, then the manifolds would leak, glow red, and the engine wouldn't rev past two grand.
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[OARNGESI]

Try it temporarily then if need be throw another muffler on it given you can weld

[1972RedNeck]

If you take the muffler out, you might get addicted to loud exhaust.

V6's sound GREAT with dual exhaust. IMO, they sound better than a BBC.

[hugger6933]

If you suspect an exhaust problem, place a vaccum gauge on the manifold side and drive the truck down the road. The farther you drive the gauge should start to drop. The loss of vaccum would indicate that the exhuast is plugged.

[cdowns]

Originally Posted by OARNGESI

Try it temporarily then if need be throw another muffler on it given you can weld

quite a few million mufflers have been installed without welding taking place

[a_barth]

Cut it off 6 inches to a foot before the muffler. If you don't like it and it makes no difference then get a coupler and put it back on.
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[Longhorn Man]

Originally Posted by cdowns

quite a few million mufflers have been installed without welding taking place

Even from the factory!

I still say this will be a waste of time. One PSI of backpressure will make the engine fall on its face.

[BMERDOC]

Everyone has given you good info. If suspect a plugged exhaust I will at least loosen the exhaust at the header and see if it has more power. Depending on what condition your exhaust is in you could either uncork it at the header/manifold or take the exhaust down completely. Shoot us a pic of the muffler/exhaust so we can get an idea of what condition its in.

[fastwillie 696969]

check for a potatoe ,it might have grown inside the pipe LOL

[Jeffs70]

have you checked the transmission fluid lately. that would be my first guess to check.
if that is fine then I would go along and check fuel filters, any small thing like that can cause things like this to happen.
also since you mentioned the black smoke from the tail pipe that means somethings getting through the tail pipe so it dont sound to plugged up. but never know. just some thoughts any how.

[eurospec1]

Its not the muffler, the black smoke is the culprit, its running way to rich

[1972RedNeck]

If you take the muffler out, your could put this in.


PIPE

[ChevLoRay]

A friend of mine was in the USAF and stationed in Puerto Rico. He bought a '54 Dodge from a guy who said it just wouldn't run. So, my buddy tinkered with it and remembered the guy saying that it was too loud and he had stuffed steel wool up the tailpipe to quieten it down. Well, rich mixtures and a bit of oil will eventually cause a blockage in the exhaust system that will hamper performance, especially when the steel wool is there to trap it.