Exhaust huff-huff-huffing engine sounds fine though..

[Sneaker]

I am trying to figure out where to start... The exhaust sounds like it is huffing at speed and idle. The sound is not a pop though. Engine runs fine and no vibrations. Anyone else have this before?

Thank you..

 

[73m819]

BURNT EXHAUST VALVE, or bad exhaust spring, could also be a bent up exhaust rocker, exhaust valve is not closing or not staying closed all the way

 

[phil2968]

I would start with valve adjustment. Easy to do.

 

[91W350]

Does it do it when pulling hard? Does it do it when running steady, like 1200 or 1800 rpm? Glen

 

[glcaines]

One trick to check the compresson and see if a valve is sticking open is to leave the fuel shut off and engage the starter. The engine should turn over evenly. If you get a skip where the engine speeds up, that cylinder has lower compression. Mind you, this is a very primitive qualititive test. If you don't get any skipping, that doesn't necessarily mean that you don't have valve problems. If you do get skipping, you definitely have a problem.

 

[91W350]

I have one that is constantly searching for a steady rpm. As long as it is pulling, it runs smooth. When you let it idle or try t level off at an rpm, it wants to hunt. I think the governor is sticking. I added some Marvel Mystery Oil to the crankcase and it is much better. What it really needs is driven. It had been parked since 1992. I should load it up and go to Nebraska or something. Great running and driving truck, but it does the whoop whoop whoop thing when trying to run easy. Does not matter what rpm, idle or 2000, with no load it never would settle down and runs smoothly like it should. I will get it there, or replace the pump...