tick through exhaust

[Onequick26]

I have a stock 390 in my truck and at idle there is a tick from the right header. I'm thinking a burnt valve but not sure. Dose anyone have any other ideas ? I have never been in the engine just put it in and drove the truck. Off idle I can't hear if it still dose it.

 

[phillip-r-s]

stock 390 has it ever been rebuilt if not it very well may just be a lifter in need of adjustment. put a screw driver, piece of tubing, or steth-a-scope up to the valve cover on that same side n listen. i'm no pro so you know

 

[sneakysnake]

Do a compression check, it will tell you if you have a bad valve,or just a ticking lifter.

 

[spannerswatson]

can also be a small exhaust leak at the manifold gasket

 

[LOWANDRATY]

390 Fe engines

All the Fe engines use a shaft style rocker system, no adjustments on those motors, the rockers are all on the same long shaft and the bolts hold the shaft down not the rockers, if it is a ticking lifter, add a quart of marval mystery oil next time you change the oil, and it will flush out the lifters and make them quiet again, eveybody calls them boat anchors, but I have had quite a few of the old motors that ran very well and they were almost bullet proof, big old heavy cars and trucks and would still run like heck.

 

[sgtpontiac]

I'd try the fix from LAR...

All the Fe engines use a shaft style rocker system, no adjustments on those motors, the rockers are all on the same long shaft and the bolts hold the shaft down not the rockers, if it is a ticking lifter, add a quart of marval mystery oil next time you change the oil, and it will flush out the lifters and make them quiet again, eveybody calls them boat anchors, but I have had quite a few of the old motors that ran very well and they were almost bullet proof, big old heavy cars and trucks and would still run like heck.

Could be a sticky lifter or chatter from varnished rocker..... if that doesn't do it.. pull the rocker on the side you think is making the noise and see which one is making the noise..... if the valve were burned I'd think you'd have a miss..... whether exh or intake you'd have a dead hole....if intake it might even pop thru the carb on accel.... JMHO but I'd try the MM oil or other name brand varnish remover/cleaner...even trans fluid will sometimes clean it out if it's a sticky lifter.... [P

 

[rainman]

can also be a small exhaust leak at the manifold gasket

If you're not getting at least a little rough idle, I'd bet on the exhaust leak!!

Rough idle, lifter (best case), burnt valve (worst case). JMO

 

[Tripper]

If you're not getting at least a little rough idle, I'd bet on the exhaust leak!!

My Ranchero's 390 started to get a lil tick on the passenger side & it turned out to be an exhaust leak between the header & exhaust pipe... sounded just like a valve clickin'! [S

BoB

 

[sgtpontiac]

Looks like the consensus is to check for the Exhaust leak....

sometimes I assume that the easy check stuff has already been done....but I shouldn't as not everyone has a tech background or even any experience at all.... sorry.... I'll try not to look beyond the obvious...thanks guys for keeping my feet on the ground.....

 

[burnin#2]

for sure check the easy stuff!! before you pull the valve cover and start tearing into that stuff, pull the exhaust manifold and check to see if there is any blackening on the surfaces, this points to a leak. and ive heard the exhaust manifold leaks, they are JUST like a ticking valvetrain. id put money on a exhaust leak!! [P[P [cl

 

[dyce51]

my vote goes to an exhaust leak.....gasket between block and header.

 

[sgtpontiac]

Even if they are cast irons they'll leak.

my vote goes to an exhaust leak.....gasket between block and header.

Some cast iron manifolds don't even use gaskets... could be warped, loose bolt...??? Yep, check all the easy stuff first.... the less you remove, the less you have to put back together..