We all need to let off some steam from time to time when the pressure builds up too much, and it's the same kind of thing that your Nissan Pathfinder-or any vehicle, for that matter-needs too. In fact, with every cycle that your engine runs through, it reaches a point where it needs to let all the heat and by-products out into the world to start the cycle again-several times in a few seconds, in fact. The key here, however, is correct timing. An engine does all the things it does-even release exhaust gases-at the right time. With a damaged exhaust manifold gasket, the timing of your system might be thrown off by premature discharge. Here are a few signs to watch out for to find out if your vehicle's gasket is on the fritz, including quick solutions you can do to address them.
If you notice that the engine is particularly rough-yet the indicator doesn't seem to peg the problem down to the engine itself-it might be caused by a leak somewhere along the lining of the gasket that is throwing the timing of the engine cycle off. This is a much better alternative to the actual engine unit itself being completely messed up. If you notice this symptom, immediately pull over to the side of the road, shut down the engine, and inspect the exhaust manifold gasket for any damage or breaches. No matter how small the breach is, cover it up immediately with epoxy putty so you can keep going-but replace the entire gasket when you have the chance.
Another symptom that's much harder to detect is a whistling noise coming from under the hood. This is caused air being forced out smaller breaches in the exhaust manifold gasket. You're not likely to hear anything if the breach is too big. If you hear it, it's best to seal off the damaged or breached areas along the exhaust manifold gasket-until you get a viable replacement.