Little tick

[78Chev]

Finally have everything rebuilt from scratch and back together. Runs awesome. (1000 miles on rebuild.) But like so many of our rebuilds it has a slight lifter tick which is only noticeable from about 140 to 180 degrees. At warmed up (192) idle and off idle and foot into it it sounds perfect. Should I worry about this (seek and replace the offending lifter), use the ATF method a few times, or just forget about it? (I shouda but didn't put in new lifters at rebuild since they were pretty new.) Thanks.
Randy

[john8662]

I don't think it's a lifter :)

Is most likely an exhaust leak (after further troubleshooting of my own) which will make a ticking sound.

Is it heard mainly when driving (engine load) or just sitting their idling?

If when you take off you start hearing the tick, it's exhaust leak due to enough exhaust volume to make the noise.

The banks turbo system on your engine uses a crossover pipe that is secured in two ways.

On the passenger's side it is secured with machine threaded studs into the manifold below the turbo with nuts and lockwashers holding the triangle flange to the manifold separated with the Banks gasket (not a donut).

On the Drivers side (problem area) the pipe is flared out just like any other exhaust pipe for a donut seal. But, the factory long studs and springs and locking nuts are re-used. With a pressurized system, there isn't enough torque on the flange to properly seal in my opinion. I'd suggest fixing this one of two ways..

Remove the studs from the manifold and use replacement bolts of the appropriate length to firmly hold the pipe via the flange to the manifold.

Keep the studs, but remove the springs and replace with (many washers) or a piece of 3/8" pipe cut in 1" sections to slide over the studs and followed by the nuts.

Should apply enough pressure on the donut to make a better more positive seal that's not going to flex and move (as previously allowed).

I haven't done this modification myself, but am planning on it, time permitting...

There is the spill.

J

[78Chev]

Thanks, John.
I guess it could be an exhaust leak. That might explain why I only hear it during certain engine temps -- the manifold expands and seals the leak, perhaps. In the past I have actually done the remedy that you suggested. Some time ago I cut some bronze spacers about 3/4" long and put them in place of the springs on the driver side exhaust to mash and seal the donut gasket. It was obvious that the springs weren't going to do the job. Can't remember if I used them this time or not! As I recall they needed to be a bit longer than I cut them (as you suggest) as they bottomed out before the gasket sealed as tight as i wanted. I should probably replace the donut too. Next time I change oil I'll give that a go (it's easier with the oil filter out of the way). I'll also check other places where I might be getting an exhaust leak on the crossover joints. Will check all the exhaust manifold bolts too.

It sure sounds like a lifter, though. I don't hear it on startup (but the thing has a healthy rattle). I hear it as the engine warms up when it is in gear and idling but before it reachers operating temp. If I put it in neutral and use a steth to locate it, I can't really find it and it seems to fade away. When I step on it from a stop I don't hear it. And like I said, when fully warmed up the engine sounds great (although I'll never get used to the exhaust pulse caused by the Banks).

The noises these 6.2's make can drive one mad!
Randy