This has just started recently, but when the engine is warmed up, and at idle after I run the engine above 1200RPM or so, I get this humming - almost sounds like a faint trumpet - coming from the carb area. I've unhooked all of the vac lines running to the carb and in the area of the manifold (one at a time) and the only thing that seems to stop the sound is if I pull a big air sucking vac line (while it's going - it happens almost randomly. I can rev the engine once and it won't do it, rev it a few times and the sound will start up. Also, if I let it idle for a while, it will randomly start and stop.)
I'm leaning toward it being the EGR (though I pulled the vac lines from it and it really didn't make a dif - pulling the main line did make it stop humming, but it was about to stall the engine at the same time). Anyone else have this weird sound and know what the cause is?
I'm leaning toward it being the EGR (though I pulled the vac lines from it and it really didn't make a dif - pulling the main line did make it stop humming, but it was about to stall the engine at the same time). Anyone else have this weird sound and know what the cause is?
