Your idle will jump up and down. You may also feel a misfire, due to the vacuum leak. You may also hear a hissing sound from the engine. Nice job you nailed it. But if you hear no hissing, you can spray some brake cleaner around the intake manifold. You'll definitly hear it. The cleaner will remove any crap blocking it from the hissing. Easiest gasket to replace.
Bad echaust manifold or header gasket. Or loose header or manifold gasket.. if its just a loose bolt the gasket will eventually crack or break from pressure.the popping sound is high pressure leaking past the gasket Bad echaust manifold or header gasket. Or loose header or manifold gasket.. if its just a loose bolt the gasket will eventually crack or break from pressure.the popping sound is high pressure leaking past the gasket
check for loose fan belt may also be intake manifold gasket leaking
Intake manifold leaks will cause the engine to idle rough and get poor fuel economy. An exhaust manifold will have no symptoms other than the sound of the leak.
Exhaust manifold gasket leaking
Exhaust leak at Exhaust manifold to head gasket or oring at exhaust manifold pipe.
A pressure test on the cylinders will tell if you have a bad head gasket. If you hear a whistle sound near the intake gasket, spray WD-40 (or any type of petroleum spray) on the area and if there is a leak the engine rpms (or engine sound) should change.
A exhaust manifold that is warped, cracked, or missing a gasket will make a sound like a engine miss. I usually look for soot near the suspected area to tell for sure.
Noises have to be heard to be correctly diagnoised but just guessing, I would say it is a vacuum leak at either the throtle body or intake manifold gasket. Get some carb cleaner and CAREFULLY spray the intake and throtle body to find it.
sounds like you have a loose rocker arm NEW ANSWER: A exhaust manifold gasket leaking will sound like a lifter also.
As with any internal combustion engine, the vacuum leak can be anywhere on the intake side, including intake manifold gasket, cracked intake manifold, EGR valve, throttle body gasket and even the vacuum operated devices can contribute to leaking, such as the vacuum assisted brakes or vacuum operated vent system. Starting fluid can often be helpful when searching for a vacuum leak; search the likely places, listening for the the typical hissing sound. Once you find a place that you suspect of the leak, spray a little of the starting fluid. When the starting fluid hits a vacuum leak the engine RPM's change slightly. Good luck.
Check for a vacuum leak around the throtle body and intake manifold.
Listen to it. if it is making loud noise you will hear it... assuming by noise you mean sound wave vibrations within the range of human detection...