4-runner Engine Noise

[msimpson]

Hi all, new to this forum. I have a 1986 4-Runner and today while driving to work I detected a noise (65 mph) that sounded much like an exhaust leak. When I slowed down the noise was present throughout the driving range but only while the accelarator was pressed. At idle there is now noise at all, idles nice and quiet.

I have checked the entire exhaust from the engine back and can find no leaks, the engine seems to be running hotter than normal but I do not have any temp gauge other than the coolant. There is no oil pressure gauge either.

The motor had a head gasket replaced 18 months ago, new timing chanin tensioner, and asorted other little things done but no water pump or oil pump replecement at that time.

Is there anything that could go bad within the engine that would allow it to idle as quiet as ever yet step on the gas and sounds like an exhaust issue? If I give it gas in neutral it revs up fine with no noise, only under load (while driving) do I here the noise.

Not much to work with but if I don't get any suggestions it's going into the shop. I did the head job but am at a loose with this.

Thanks!

Mark

[Andy]

Look at the rubber trunking that goes from air filter to the engine inlet pipe, they sometimes split and make this noise.