(1997 4.0 ohv) okay so yesterday i drove through a drive-through and noticed a slight tick of the engine. (i had the windows down and no AC or heat on) almost like a pen being clicked. seems like it keeps pace with the rpms. the truck has also been throwing lean codes. she only does it when the engine is hot and at idle. cold she idles without a tick. its very annoying and drives me crazy even though it is quiet. any ideas or suggestions since im a newbie mechanic? any help is appreciated.

 

The 4.0 is naturally a noisy engine, and the tick is just the valve train. As for the lean codes the first things I would check/replace is the MAF and the fuel filter.

 

thanx man took a little of my shoulders..And unfortunately I have already cleaned the MAF and airbox pretty good. Also replaced my fuel filter. Might check for vac. Leaks or check my intake manifold. Upstream O2 sensors maybe? Anyone who had these damn lean codes and fixed them I'd like to here your input.

 

lean and a tick can be a bad injector.

 

If your getting lean codes on both banks then it's your intake gaskets.

 

getting **** poor gas milage.. also a slight smell of gas do you think it could be the injectors also? she idles VERY rough until its warmed up. ive cleaned IAC, MAF, and replaced fuel filter and problem is still there. want to know anything else before i start throwing parts at it.

 

Gaskets man

 

I had a crack in the crook of the "Y" exhaust pipe which caused both banks to read lean. Good luck.