scary ticking noise that comes and goes..

[jshouse]

after about 5 mins. of driving, everytime i drive it, the truck starts this loud, almost scary sounding ticking. the noise lasts for about 5 mins., and goes away.

it is really loud, a lot louder than the supposed "piston slap" i had in my 02 2500. i have heard that it could be a sticking lifter, but i thought that would happen right after start up? this is almost like clockwork, it starts at the same spot in the road on my drive into work, and then at the same spot again on my way home, which due to traffic, are different spots. both about 5 mins. after startup.

it almost sounds like a VERY loud exhaust leak, but still has a kind of "metallic" ticking in it. and seems to be coming from the drivers side of the engine bay, it that makes sense.

i have done the seafoam treatment twice too.

any ideas or recommendations?

[RedHeartbeat]

Sounds like something to do with and EGR valve.

[TXsilverado]

how many miles on the motor? running some seafoam through the bottom end would help with any possible stuck lifters. pour a bottle into your oil according to the directions on the bottle and drive it for about 20-30 miles and change the oil immediatly while its still hot. im assuming your oil pressure and everything are fine. its definately not piston slap if its 5 min into the ride. piston slap is usually within the first minute of a cold start.

[TXsilverado]

Sounds like something to do with and EGR valve.

if its not the egr, its not a bad idea to remove it anyways IMO. emmissions suck hahaha.

[Jamest]

I had the same thing on mine and it was the 1st exhaust port leaking due to the manifold bolt being broke in the head. It only leaked when it got warmed up. When Allen put on the Trick Turbo he had it extracted at a machine shop when the heads were off and getting cleaned up. I don't know if this is your problem, but it sounds very similar to mine?

Jamest

[txarkitekt]

Hmmmmm...sticky lifter? Try the method Stewart outlined. That should take care of it. If not, go try and use some Motor Flush. Does the truck run rough at all? any SES light? I think Red is onto something with the EGR too...

[GenIII_4Ever]

u check and make sure u dont have any exhuast leakes

[metalchips]

Sounds like something to do with and EGR valve.

I am guessing, but I would run a vacuum line right to the EGR valve. Activating and deactivating it and listening to your noise. Sound like when it comes up to operating temperature it turns the EGR valve on.

I looked at your year 79, that had vacuum EGR.
A LS1 uses that sparky electrical stuff! so my dumb Idea will not work

[1slo4.8]

my motor ticks too! i don't know what it is though. is still runs good though?

[jshouse]

thanks fellas..i will try a few of these things and see what i can figure out.

and the truck runs great. i still need to get a touch up tune, but the performance and driveability is the same when its making the noise.