Knocking, weird noise and smell of fumes

[kaised]

Heres the deal - I have 3 different issues and I'm pretty sure they're all related to the same thing but I'm not sure exactly whats wrong - maybe one of you has a suggestion.

Issue 1: Engine knock at idle

Issue 2: When driving it sounds like air is escaping somewhere from the engine on the upper drivers side but I've looked while its idling and can't see anything, checked the headers and they don't appear to be leaking? I thougt the leak might have been around where they attach to the manifold.

Issue 3: The smell of "raw" exhaust around the engine compartment. It smells kind of gassy, like its not passing through the cats.

Any help? If it matters its a 93 X w/ 200 K miles

 

[Nate1]

Well, I dont know a ton about this, but I would say check your intake manifold gaskets first... then your head gasket.
Those two would give you pinging and probably cause the other problems.
-----Nate

 

[Limited Ex]

I have the same knock in the engine when it is idling. I just spent the past few days replacing all the intake manifold gaskets, both valve cover gaskets, EGR valve gasket and the IAC valve gasket. And after all that I still have the knock, which leads me to believe that its valve clatter. So if I were you, before I tore apart my engine, I would take a look at my valves and see if there is any wear on them.
As for the gas smell, it may be the rubber hoses coming off your evaporation canister under your hood. I too have noticed the same thing, and the problem is the hoses on the canister are really old and cracked. The evaporation canister is on the drivers side of the engine compartment, right behind the Washer Fluid/Antifreeze reservoir. Its got two "knobs" coming out of the top of it, with hoses running off the side. Check those and see if they are badly cracked.

 

[kaised]

I know its not a head gasket - I went through that once before so I now know the symptoms! Would a bad intake manifold gasket result in an exhaust smell under the hood and a noise?

 

[DonM]

Stupid question but...do you see any sign of gas? Leaks or anthing? Can you locate the raw gas smell to a general area?

What about a leaky FPR?

I say inspect the engine over 100%, make sure everything looks normal. Tighten down the lower intake bolts. Make sure all hoses are secure. Also check for missen caps!

Could be a million things...

 

[TPLYNCH]

Make sure you don't have any cracked or loose Vacuum lines.

 

[kaised]

I've given the engine a once over and nothing looks out of the ordinary. Definitly no leaking gas. I'm thinking it might be a manifold gasket, but I'm not sure if that would cause all the issues I'm having. Whats the quickest way to test vacuum lines?

 

[Nate1]

Well since the intake manifold leak would only draw air in past the sensors to detect the amout of airflow, it would make your engine with a bad air/fuel ratio and cause it to ping and idle rough.
As far as the gas smell... is it exhaust, or is it gas? That would make a big difference.
-----Nate

 

[kaised]

Definitly exhaust - it just smells very raw - like the smell you get from an old pickup truck