Below is a link to youtube that has a video I just took, of my engine. Its making some weird knocking and tapping, also, its vibrating weird. Or is it just me and it seems normal. I did a rev up and down, etc.
Thanks for your opinions... just seems like its sounding strang...

http://www.youtube.com/watch?v=fAbz_11sZEU

http://www.youtube.com/watch?v=NKftWJ6qklI

 

mmm, its kinda hard to tell. but maybe if you can pinpoint where the tapping sound is coming from it can be easier to figure out. maybe an exhaust leak? or does it sound like its coming from inside the valve covers?

 

I would guess its comming in top of the engine. I took a stethlascope, and took poked it on top of the engine, i could not pin point the source.

Why would you it would be an exaught leak?

I don't know if its the lifters as well. I have noticed, once the engine is warmed up, the sound is bearly noticable.

 

are you running the correct firing order?

 

it's very hard to tell as camera and compression take some of the audio away so that all you here is this knocking, which could really about everything
it seems to be down to a specific cylinder though. the first thing I'd do is check the exhaust manifold gasket on the bank the noise is coming from. if that leasks it actually sounds like loud valve tapping instead of a pfff pfff some might suspect. Check if the bolts on exhaust manifold are thight. So if you're lucky and mustangdemon is right, then that's all there is to it. Warming engine expanidng might explain it as well.

if that is not the case then I'd say adjust valves and then do a compression test.
But yes, ya. make sure you have the firing order ok.

kalli

 

Ok. What I will do:

1 - Check the firing Order. Its a 68' 302 V8.
(BTW, I have a new distributor and wires)

2 - I will unscrew all the exhaust manifold bolts.

3 - I will screw / bolt them back in as tight as I can.

4 - Compression Test? how do I do that?
(If a cylinder does not have enough compression, does it make a knock knock sound? And how would you cure the problem?)

thxs

I just want it to be smooth.

 

If it is under the valve cover (rocker arm, pushrod,...) it should be easy to locate with the stethoscope to within 1 or 2 valves by sliding along both sides, and top, of the covers. I just did this a couple of weeks ago to track down a ticking noise. Wound up being a bad rocker arm. It was loud and clear when I got the stethoscope near the bad arm. (We also isloated other softer tapping to the bearings in the pwr steering pump the same way.)

If its somewhere else in the engine, I would think you could narrow it down if you can get close enough to it with the scope. Getting less noticeable as the engine warms up seems like it might rule out some possibilities.

 

How bout this for a thought... I think I rememeber, a long time ago, My dad and I were working on this engine.... I think one day we took off the valve covers and tightened down both heads. And after that day, I think the knocking started. Maybe...

Anyways, what would you think then? A blown gasket, Head, valve?

 

that sounds like rod knock to me,...maybe a shot bearing

 

ik think it's quite impossible to tell over the audio. you should get someone to listen to the car who knows.
don't unscrew the manifold/header bolts. just make sure they're tight.
i was thinking about a compression test just to figure out which cylinder might be a problem, but that's not guaranteed to tell you. as well you will need a compression tester. maybe a mate of yours has one. Don't buy one just for this sake