Signs of an intake leak ?

What kind of leak? Coolant or Air?

Maybe, sometimes. All depends on where the failure is.

Air leaks, on a modern fuel injected car, would cause the car to idle higher and use more fuel. You would also usually hear a whistling sound.

Coolant leaks would make the car sluggish, more so after making a turn with certain engines as puddles of coolant would get sucked in faster. It would only sound different in the since it sounds like its struggling or with wet fouled plugs it wouldnt be running on all cylinders or at all.

A simple cooling system pressure test will alert one to such problems.

I guess I'm asking about a coolant leak. Coolant seems to be going somewhere with no exterior visible leaks. It's a 94 Grand Am v6 3.1. Runs pretty good. Idles good, occaisonally idles a bit rough when damp. Also seems to be excess smoke coming from the tailpipe. If coolant is leaking into the engine, will it cause irreversible damage to the engine, or will it just burn off ? I have taken the car into my mechanic to check it out, but haven't heard anything back yet, so I am just inquiring on here while I wait.

3.1's are known to have gasket failures. Sometimes they have been known=20 to cause severe damage from hydrolocking. But thats a major failure of the= =20 gasket. Yours on the other hand isnt leaking as fast but coolant goes=20 right past the compression rings and gets into the oil. Coolant in your=20 motor oil is not a good thing. Bearings wear out rapidly with coolant in=20 the oil. Also most of the coolant tends to go out the pipe but the stuff=20 that makes up coolant tends to clog and stick to O2 sensors and catalytic= =20 converters. Silica in the green coolant tends to really stick.

Thanks for the info. I'll have my mechanic check for any leaks.

3.1's are known to have gasket failures. Sometimes they have been known to cause severe damage from hydrolocking. But thats a major failure of the gasket. Yours on the other hand isnt leaking as fast but coolant goes right past the compression rings and gets into the oil. Coolant in your motor oil is not a good thing. Bearings wear out rapidly with coolant in the oil. Also most of the coolant tends to go out the pipe but the stuff that makes up coolant tends to clog and stick to O2 sensors and catalytic converters. Silica in the green coolant tends to really stick.

A lot of late model engines with aluminum intake manifolds have problems with the intake gaskets leaking . Usually coolant loss wil be gradual,with intermittant loss of heat,gurguling in the heater system. It can also destroy an engine by getting the coolant into the bearings.Usually it can be detected by a milky goo found on the underside of the oil filler cap etc.