Well I haven't been on in a while but I have been around. Anyway start my car up for the first time in months because it was finally nice out and right off the bat I notice a loud sort of smacking sound as some would call it coming from the passenger side of the engine. It increases in speed as the RPM goes up and is kind of loud. I know it cant be knocking because my Intrepid threw a rod and it sounds nothing like it. I was thinking maybe the valves or something but I really don't know very much about engines. Anyway its a stock factory L98 and it is full of oil and was changed about 2k miles ago. Any ideas???

 

Remove the drive belt(s) & restart the engine. Might have a noisy pump or alternator.

 

+1 on this, lifter could have commited suicide over the winter also.

 

Ugh I am hoping that if it were to be any of those things it would be the alternator. Just because it involves a little less engine tearing.

 

Yo i just fixed a knock just like that on my car



Yours sound like this?
http://www.youtube.com/watch?v=aI3lT6ObkSs

 

Um I will have to check on that but mine is not that prominent as yours is.

Also, yesterday I went out to start it for a friend to show him the sound that the car was making. I start the thing and it runs nice and smooth and isn't making the sound. So I let it run for five minutes and give it a few light revs and still no funky sounds from the engine. Then again it did reach 70 degrees outside so I am not sure if it is determined by temperature or something.

So this thing is starting to confuse me.

 

So do you want me to remove all the belts? Well excluding the timing belt of course but the rest then? So I guess it would still work theoretically except it would just run off the battery entirely then.

 

have you tried a mechanics stethascope or a something similar to isolate the noise?

 

Yes remove the belts & run briefly to see if the noise is still there.

 

Is it possible it's an exhaust leak? They can make really odd noises sometimes.

Is it in a steady rhythm? If so let the car idle and count how many times it does it in 10 seconds. Multiply by 6, and you get an occurances per minute number. See if it's 1/2 the RPMs or if it matches teh RPMs. That will tell you whether it's bottom end related, or valvetrain related.

 

If it only does it when it is cold it could be piston slap or a bad lifter that doesnt like the thick oil when its cold.

 

It is a steady rhythm and I am sorry I am slow on my responses but results will have to wait until tomorrow at around noon.