on a 1997 nissan pickup 241,000 mile 2.4 liter what are the signs of a bad manfold gasket.how can i test it.
Exhaust manifolds will emit exhaust gasses and make a lawnmower type noise; intake manifold usually leak to the outside, but can also m leak to the inside, in which case you ill get white smoke out of the exhaust and your engine’s days will be numbered.
What are your problems?
If you describe them, perhaps we can help.
Do you have a check engine light on?
Post fault codes, please
Rough idle?
If the intake manifold gasket leaks in a way that allows unmetered air into the engine, you might get an assortment of troubles, like rough idling, stalling at stoplights, surging, and hesitation on acceleration. An intake manifold vacuum measurement would be one place to start if you think the gasket is failing. Be sure to check the PCV valve for proper operation too.
To test for a leaking intake manifold, start the engine and while it’s idling take starting fluid, carb cleaner, or something simular and spray short burst around the intake manifold. If the engine idle changes in any way you’ve found the intake leak.
Tester
Very good idea @Tester.
I had a nissan altima with a bad intake gasket and used the same method as tester described. Should the leak be small, you may be able to fix it by taking a small brush, dope it with some indian head gasket glue, revv the engine and carefully brush the suspected area. The revving will suck the glue in and may very well seal the area, if it is small enough. Worth a shot before you take the intake off. On the altima that was a pain to do.