What are the symptoms of a bad intake manifold?

Answer 1

The most likely evidence is an oil leak which can run on to the manifold creating smoke, depending on how bad it is. If the gaskets are bad the covers can't be tightened down suficiently to create a oil tight seal.

Answer 2

Don't generally see an intake manifold go bad, it is usually the intake manifold gaskets that go bad in which case you may see engine coolant leaking out in the corners or worse case leaking into the engine and mixing with the oil.

Answer 3

For me, I smelled the exhaust whenever I would have the heat or a/c on, especially at a higher fan speed.

If a exhaust manifold gasket is badly broken you may hear a knocking sound that may sould like you have a rod knock. Also you can at times see black soot like you would find inside mufler. depending on yor car, newer cars dont leave much soot.

Answer 4

The obvious would be coolant leaking out and leaving puddles on the ground. The less obvious would be coolant leaking into the engine and mixing with the engine oil. You may see evidence of coolant under the oil fill cap or on the dipstick itself when you pull out the dipstick. This is something you don't want to happen. This can cause serious damage to internal engine parts. So, if the coolant level in the reservoir keeps dropping and you don't see any leakage on the ground, it is probably getting into the engine.

Answer 5

* Excessive Oil Consumption * Air Filter Contamination * Excessive Oil Leakage * Rough Engine Idle This link will help you even more. http://www.logantradingco.com/ldrweb/pcvvalves.htm