tapping noise

[blacklsc1]

ok this past week i'd figure id treat my mark 8 to a new radiator(it had a slow leak), new water pump, 200 amp alternator, and a set of underdrive pulleys. It all went smooth, but when i started it i noticed a rather loud tapping coming from the passenger side of the engine. I took the belt off and ran it(to rule out all the accessories) and it is still there. The car never made any noise before, it doesent even make any rattle on startup. What or where do you guys think this noise came from all of a sudden? However in a rush to get the car done i did try to hammer on the balancer. I gave it a few quick shots with a hammer and a block of wood.(after about 10 hits, i drove across the island and borrowed the correct tool)Now im scared this thing is gonna let go.

 

[jrherald420]

Timing chain slap??? Does it tap faster with higher RPM's?

 

[XLRVIII]

how long since your last plug change.

if its a loose spark plug, it wont "tap" very long before it ejects itself.

I'm jus sayin'

 

[CobraStar_LS8]

I think Tommy is right as I did get a loud tap when one of my plugs shot out and busted my coil

 

[blacklsc1]

naa, i just changed them, and i double checked them(though i have to change the valve cover gaskets soon) the tapping does speed up with rpm, id say over 1800rpm you cant hear it anymore, but at idle, you can hear it. Its weird because it dident make a sound until after the water pump, alt, underdrive swap.

 

[LaserSVT]

Tripple check the plugs when the engine is cold.
Id put money on tensioners though.

Then again my 96 Cobra had a quiet tap noise. Replaced the chain tensioners and no luck. Changed all 32 lash adjusters.... no luck. Sold the car and the new owner rebuilt the engine. It was rod berings.

 

[blacklsc1]

i might agree with tensioners. however all of a sudden?? anyone ever do guides and tensioners on this motor? i would imagine the motor would have to come out if not lowered.

 

[CobraStar_LS8]

no luck. Sold the car and the new owner rebuilt the engine. It was rod berings.

it does give a loud tapping sound and also goes alway at high RPMs

 

[MediumD]

i might agree with tensioners. however all of a sudden?? anyone ever do guides and tensioners on this motor? i would imagine the motor would have to come out if not lowered.

You could do it in the car... Personally I'd just sell it and buy another one unless it's in great shape otherwise.

 

[blacklsc1]

i just dumped some money into it, and i dont think id get much for it with a tapping motor. so either i pony up and fix it, or just drive it till it blows(which i dont want to do) so i just gotta figure out if the repair can be done in the car. Somebody on this site had to have done this repair before?? anyone??

 

[CobraStar_LS8]

I thought we can take the Timing Chain Cover off with the engine left in the bay???

 

[XLRVIII]

naa, i just changed them, and i double checked them.

Did you double check them AFTER the tapping started???

Trust.. this is not something you want to "overlook"....I'm jus sayin'

 

[blacklsc1]

yep, i actually pulled them all out, and changed them right after

 

[blacklsc1]

ok, i ttok the pass side valve cover off today, the only thing i saw is on the primary chain, the bottom on e is tight(it has the tensioner pushing on it) but the top one is loose. now the guides are in good shape, nothing is tore up . Is that normal for the top part of the chain to be loose?? does anything hold it up against the guide?? i couldent see anything. does anyone have a pic of the front of the motor with the cover off?