So the old gal has picked up a new noise. It happens most when it has sat a while (overnight). It kinda sounds like a loud valve tick, but iisn't consistent. It happens under acceleration, like ping, but isn't as sharp as the 'ping' of pre ignition (and I have rechecked the timing). And the tick greatly reduces after running on the highway a while. I've read that failed lifters can cause a tick, but the videos show it happening at idle which isn't the case for me.

Do valve associated ticks vary with load? Is it likely that the noise is something else?

Thanks in advance

 

Lifter and valve train ticks usually vary with oil pressure, which varies with rpm. If you want to make triple dog sure it's not pre-ignition, unplug your vacuum advance line at the dist and put a screw in the line to plug it off, Then drive it for awhile and see if the tick goes away. If it's still there, you can plug the line back in and look for something else. An engine valvetrain can tick for miles and miles and not cause any serious damage, so I would not panic over it.

 

Do you have any idea what the inside of your engine looks like, for caked up oil or sludge ? How often have you been changing the oil ? You may want to try a can of Gunk Motor flush before the next oil change, a little ATF they say works good as a cleaner too.

 

Thanks! Will give that a try.

 

When I got her about 12,000 miles ago, the ports were FILLED with carbon. I must have taken out close to two pounds of it. The pistons weren't bad and cleaned up well. The lifters all had some grunge and at least one was pretty close to plugged up; all cleaned up nicely.

The first couple old changes were done at around 500 miles with a 5-10 pre change flush with a quart of diesel. After those, I increased the interval to 1000 then 1500 miles (when the oil had changed from honey color to very dark). This last change was at just shy of 3000 miles.

Also, I just changed the plugs after 10-12,000 miles. One and two had some white deposits on the side electrode, but were clean otherwise. The other four had a nice light tan color and no deposits. I probably could have knocked off the deposits, regapped them, and been on my way.

 

White on the plug sounds like it was running lean, could it be a lean knock?
Have you tried to tighten the manifold to head bolts?
It could be exh leak at the head & manifold.
Dave ----

 

Try running a tank of premium and see if that makes any improvement. If so, you'd know lean knock was at least part of the equation.

 

I agree with Fuzz face on a manifold leak. Those 6 cylinder engines are prone to develop exhaust leaks. If you let it go too long you will flame cut the manifold and the head.

 

When mine has pinging the AFR gauge goes rich that is kind of strange.
I am already going broke filling the truck with regular.
If I was to fill up with high test I would not be able to eat for weeks
I kind of like eating
Dave ----

 

People call me fat, but I tell them my belly is my hedge against high cost food.

 

Okay, I'm a bit slow... I can understand why a leak on the intake side can make it run lean, but why would an exhaust manifold leak cause a lean condition?

 

Ha! Myself, I have the body of an Olympic athlete.

On a totally unrelated note, please don't look in the freezer in the basement.

 

Not lean but the noise you hear that you started this post about.
Dave ----

 

Gotcha! Seems I'm as good a reader as Kamala is a speaker.

 

LOL NP
An exh leak at the head can make weird noise.
Dose it make it more when under load?

I seen it posted that someone used a shop vac, hooked it up to blow air and fixe it to the tail pipe.
Then turned is on and use soapy water on the system looking for bubbles / leaks.
Could also do this at the head / manifold.
Dave ----