valve guide seals

[Dave WM]

here is the plan. Put it all back together, double check the lash on all valves, bore scope the cylinders, If it still making the noise (will get a video of it with sound) I am just going to pull then engine and put in my spare. The spare runs great, has the MN47 head (higher compression). I don't really want to get into pulling the head with the engine in the car.

[Captain Obvious]

Woof. Are you positive sure it's a metallic clanking? And are you positive sure it wasn't there before? Maybe you're just uber sensitive to noises right now? I'm (like you) am having a hard time coming up with anything that could cause that kind of noise as a result of a valve seal change.

So you did all six intakes? Just the intakes only?

[Dave WM]

8 minutes ago, Captain Obvious said:

Woof. Are you positive sure it's a metallic clanking? And are you positive sure it wasn't there before? Maybe you're just uber sensitive to noises right now? I'm (like you) am having a hard time coming up with anything that could cause that kind of noise as a result of a valve seal change.

So you did all six intakes? Just the intakes only?

Its obvious, I can hear it inside the car with the window up. Plus I can use the stethoscope, touch each spark plug body, its very noticeable on #5 (IIRC or could have been #6). not there at all on the others.

yes did all 6 intakes did not touch the exhaust. Its a real puzzle. The video will help will post that up today after I get it all back together. the only thing I can come up with is:

I am just really really not getting the lash set right or I bent a valve with my rubber tube technique. I don't see that as likely but the only possibility left (well short of me dropping something into the cylinder). It sounds like a valve set way loose. I triple checked the lash pads are in place (besides checking both hot and cold lash) already but cant hurt to try again.

If this fails I the only thing I need to do to the spare motor is replace the timing chain tight side guide, new timing cover gasket, new rear main seal, new pan gasket, new oil pump gasket. I will leave all the manifold stuff on as I can see no reason to replace it other than my existing setup has the egr, the spare does not, but since its dumb there should be no wiring issue other than an unused water temp switch on the t stat.-

 

 

 

 

 

 

 

[Patcon]

You could have dropped a valve seat too. It's pretty rare, but possible. It would make the valve lash wonky depending on how the valve seated against it and it would be pretty noisy. Might not be able to tell that with the camera though.

[Zed Head]

Have you tried just grabbing rocker arms and reefing them around to see if you can find looseness?  Put down the stethoscope and get rough.

You might try removing the mouse trap springs and rechecking lash.  They add extra force that the feeler gauge has to overcome.  Might not be getting the right measurements.

[Dave WM]

2 hours ago, Patcon said:

You could have dropped a valve seat too. It's pretty rare, but possible. It would make the valve lash wonky depending on how the valve seated against it and it would be pretty noisy. Might not be able to tell that with the camera though.

do you think I could feel anything with the valve spring off, and me manipulating the valve? I did try that to see if I could feel any oddness as it seated. The other thing is the leak down test showed virtually no leakage (listen for it thru the intake manifold brake booster port with a hose). All the  cylinders sounded the same.

[Dave WM]

22 minutes ago, Zed Head said:

Have you tried just grabbing rocker arms and reefing them around to see if you can find looseness?  Put down the stethoscope and get rough.

You might try removing the mouse trap springs and rechecking lash.  They add extra force that the feeler gauge has to overcome.  Might not be getting the right measurements.

I will give it a shot.

[Dave WM]

one last course of action besides the above, I plan to remove the valve cover, drape the bay with an old blanket, hole for the top of the engine, and run it with the cover off (vacuum plugged) figure I could feel the noise better this way. will make a mess, hence the old blanket to suck up the thrown off oil.

[Dave WM]

Smoking gun?1

ok #6 EXHAUST completely loose, jam nut up, multiple turns and I am still not there. I just had to come in and shout this out!!

Keep your fingers crossed, seems like this has to be it.

Now how did this happen, being old (see covid) brings along a condition known as brain fart. I MUST have started there, or just got confused/distracted and loosened that one up before moving on the intake.

anyway taking a break to let the possible joy last for a while just in case I am wrong.

[Captain Obvious]

I suspect in your senior state, you loosened up #6 exhaust lock by accident and then it worked itself out from there.

Sounds like a plausible smoking gun to me! That would be great!  Tighten that sucker back up to the correct lash and take it around the block while you're still allowed!!!  

[Dave WM]

this may sound silly but I am slow walking the adjustment, guess I want to live in the idea that this is it, enjoy the moment, make it last for a while just in case I am wrong...

Tomorrow Tomorrow

 

[Captain Obvious]

12 hours ago, Dave WM said:

this may sound silly but I am slow walking the adjustment, guess I want to live in the idea that this is it, enjoy the moment

LOL. "I gots ta know."