Ok when there is low vacuum it means the rings on pistons are bad right? And when the needle jumps around it means valves are bad or valve seats? Right. But I've also hear if you have a loopy cam it will also effect these. Mine seems to jump around quite a bit. I also have heard some clattering (I think I need to adjust my valves or at least ck them anyways) Thanks in advance.

here s a refresher course, check the different scenarios til you find a match http://www.secondchancegarage.com/public/186.cfm low vacuum can also be caused by late ignition timing, and big cams definitely have low vacuum.

Ok when there is low vacuum it means the rings on pistons are bad right? And when the needle jumps around it means valves are bad or valve seats? Right. But I've also hear if you have a loopy cam it will also effect these. Mine seems to jump around quite a bit. I also have heard some clattering (I think I need to adjust my valves or at least ck them anyways) Thanks in advance.


Yep, low vacuum (assuming you don't have a big vacuum leak somewhere) is caused by worn piston rings and even bad valves/seats. And a rapidly fluctuating vacuum gauge needle indicates bad valves/seats. Or a long duration camshaft will cause low vacuum because the intake valves are off their seats for a longer period of time. Once they're set hydraulic lifters/rocker arms/pushrods don't need any further adjustment for about 100,000 miles. Unless you actually have lash at one or more of your rocker arms/valve stem tips adjusting them won't get rid of any noise. If your heads have stamped steel pushrod guides they WILL make a certain amount of noise as the pushrods bang against the insides of the guides. If you take your valve covers off check the alignment of your rocker arms to the tips of the valves. If you see one or more that is off-center it means you either have a valve stem tip that is worn crooked (most likely) or you have a bent pushrod guide (from rough handling prior to installation).

Ok so a pic is worth a thousand words. So heres a quick vid ( you can fast forward or skip to :44) so you don't have to hear me yack. In the vid you can really hear a clicking in real time I don't hear it near that bad (then again my hearing isn't that good either)

http://www.youtube.com/watch?v=A-WXf79UpaQ

pull the valve cover , sounds like a rocker arm is loose, probably one of the exhaust valves since its backfiring..can you tell which side its coming from?

Well according to the chart (Which is too awesome I'm keeping it in my fav.) it looks like scenario #3 So maybe nothing is wrong???

yeah, that chart your kids could follow.....your vacuum is not really low, at 15-16 in hg...and when you rev and release it goes up near 26..thats usually means rings are ok....the clicking noise is a loose rocker ,I ll bet. pull that valve cover......good idea with video, tho

No more "jump" than that gauge has it's no deal. I'm not picking on your gauge, but that one is more for testing vacuum diaphragm type stuff than checking engine vacuum. There's not much damping built into that one compared to a true engine vacuum gauge. Just the normal variations in idle vacuum are making your gauge go apes***.
I'm with fishslayer- pull the rocker cover off the side you think is making the most noise, start it (yes, it'll get oil everywhere, price you pay for good diagnostics), and lay your hand on the rockers while it's running. You'll be able to feel the one that's making all the racket.
Look at the rockers, pushrods, rocker studs, springs- everything you can see- look for shiny spots, anything off center, discolored, just anything that just dosen't look quite right.

Yeah it is comeing from the driver side for sure. I have some new valve covers I want to put on anyways so I'll be sure to check it when I replace them.

Also if you guys are bored I have another quick vid of some questions.

http://www.youtube.com/watch?v=gJXXuPsuf20

I think I might make a new post just for this vid though.

Get you an old spray bottle, couple drops of dish soap and some water. Soak the plug wires, then the cap and coil area- The dish soap slows the evaporation of the water- really cool if you shut the lights down- a leaking plug wire will light up like a neon sign.

tims right, kill the lights and if spark is leaking, you will see it clearly.. Hey Tim, maybe we should start a Car MD web site, you know, with virtual engine diagnostics with web cams like physicians do . whadyathink? we could be Gozillionaires and retire in Tahiti!

Ok so a pic is worth a thousand words. So heres a quick vid ( you can fast forward or skip to :44) so you don't have to hear me yack. In the vid you can really hear a clicking in real time I don't hear it near that bad (then again my hearing isn't that good either)

http://www.youtube.com/watch?v=A-WXf79UpaQ


Your ignition timing may be advanced a bit too far. Other than that you have very good vacuum. As I'm damned near deaf I couldn't hear any unusual noise.