Clacking in the head?

[akatagyourit]

Good evening everyone,
So couple of days ago my truck overheated and blew the head gasket. Upon getting it home via tow truck and tear down the water pump had no fins (previous owner ran straight water which rusted it out, welcome to florida). I ran a compression test also just to see how it stood.

May 2016 comp test 160, 180, 180, 170
December blown gasket 60, 60, 115, 170
Since rebuild - 180, 90, 180, 170

Now as you can see it had good compression when I got it in May of this year. Blown gasket plus cracked head = horrible compression.
I bought a brand new head assembled and put it in. Got everything buttoned up and ran a compression test just to verify before going to far. Everything was great except cylinder 2. Thinking it might be rings I put some oil in the cylinder and ran the test again, only increased to 100 psi. Don't think its the rings. So this leads me back to the head. I got everything set so I could fire the truck up just to see what it sounded like. I thought it was a rod knocking from in the cab and was pissed. When my neighbor got home I had him fire the truck and listened and it sounds like theres a clattering in the valve train. . I've gotten the valve cover off again and looked everything over, but cylinder heads are greek to me. I dunno what to look at/ touch / mess with to find the issue. I know its cylinder 2 though. I also know that on the valve cover is the vacuum port for the pcv system and it was absolutely pressurized when the truck was running, leading more towards a valve leaking. I'd like to try and fix the issue without removing the head again, already spent more than I wanted to on this. Since its hydraulic theres nothing that needs adjusting so should it just be the hydraulic lifter thats and issue or what? What can I do to find the problem and fix it. I seriously don't want to tear it back out and replace the gasket and headbolts again.

 

[tomw]

"It's hydraulic..." ... right on the money. You may have a lifter on #2 that is collapsed and has yet to fill with oil and lift the end of the cam follower to push the follower against the lobe, and thus transfer motion to the valve stem.
Take a look at the followers and see if one or both can clank around on #2, compare to #1,#3, and #4 to check.
The cam cover has an air supply from the filtered air fed into the throttle body. The PCV, mounted rear of the alternator, inline with the large tube from the separator under the intake, leading to the intake manifold, could be plugged or gummed. The separator canister can also get plugged with goo. Remove the PCV, and run the engine to see if there's a heavy flow of air out the hose. It looks to be about 3/4" or 5/8", and the PCV valve is jammed into each hose, connecting them.
Sometimes a lifter just takes longer to fill up. Nothing necessarily wrong, just a slow lifter. You can pry the followers out by compressing the valve spring, and pull the 'lifter/supports' from their hole in the head if you want to try a new one, or move them from place to place. They don't care where they go, but DO care to have the same parts re-installed if you take them apart for cleaning.
tom

 

[akatagyourit]

Thanks for the response Tom. I really been doing a lot of cleaning and maintanence on the truck. I've spent the past 3 days cleaning all the grime off this motor. Replaced the camshaft, crank, and temperature sensors. New pcv valve, cleaned upper and lower intakes, and everything else I got into along with the timing belt and tensioner replacement. I think i'm going to try swapping the lifter from cylinder 2 to 3 and see what happens. If the low compression follows then I know its the lifters, if it doesn't then i'd be looking at bad valve seats?

 

[akatagyourit]

Well side note it looks like the rings failed. Took an air compressor and applied pressure to each cylinder at tdc. Air is coming out the pcv valve port and the back side of the head where oil drains to the bottom. So guess its bottom end rebuild to and setup for turbo charging weeee.

 

[RonD]

Not making much sense to be rings???

Oil in cylinder should have jumped up the compression numbers on #2 if that was the case.

And all rings leak air, metal on metal is not a good or permanent seal, isn't suppose to be, same as valves, metal on metal, they are a temporary seal, long enough to hold pressure so explosion of air/fuel mix can push down piston and power crankshaft.

Normal leak down is 90-95%, so if 100psi air pressure is applied to a cylinder 5 to 10% should leak out past rings and valves, rings mostly, unless there is a burnt valve.

I would vote for mis-adjusted valve or leaking valve on #2, with the rest being above 160psi, ring failure in just #2 is possible but less likely that valve issue

But you are there and I am not, lol

 

[akatagyourit]

I agree Ron, but testing this morning did not indicate valve issues. I put #2 at TDC, applied 100psi of pressure to the cylinder, nothing coming out of the exhaust or intake ports. Its seating as far as I can tell. May run 1 last compression test on 2 for good measure to see, but at this point i'm about to just rip the whole motor apart and rebuild it completely.

Not making much sense to be rings???

Oil in cylinder should have jumped up the compression numbers on #2 if that was the case.

And all rings leak air, metal on metal is not a good or permanent seal, isn't suppose to be, same as valves, metal on metal, they are a temporary seal, long enough to hold pressure so explosion of air/fuel mix can push down piston and power crankshaft.

Normal leak down is 90-95%, so if 100psi air pressure is applied to a cylinder 5 to 10% should leak out past rings and valves, rings mostly, unless there is a burnt valve.

I would vote for mis-adjusted valve or leaking valve on #2, with the rest being above 160psi, ring failure in just #2 is possible but less likely that valve issue

But you are there and I am not, lol

 

[akatagyourit]

So todays update:

Pulled the head again. Gave it a once over and don't see anything noticable to me out of place.

I pushed down on each lifter a couple are rock hard and won't go down which is what their supposed to do. A couple have a bit of play. I can push down and wiggle the rocker arm a good deal which is most likely the noise being produced.

Now with that said. Pulled the head of cleaned everything up, head is upside down in the garage with valves 2 and 3 closed completely. I filled the CC up with rubbing alcohol and its sitting to see if it leaks at all. After 2 hours I'm not really seeing anything for a leak showing on the valves. If anyone has any other smart idea tests please let me know.

I also put cylinder 2 and 3 on the block below the deck since they run together in travel and submerged the pistons in ATF to test the rings. Again since 2:48pm est today its now 6:57pm no fluid loss in either. So it looks like the bottom end is fine and not damaged like we originally though. Now the head is iffy as I know its not leaking, but i'm not sure how the lifters and such play into effect. Was reading some info stating that if the valves aren't opening full duration it could throw compression readings off etc etc. Not sure any gurus able to throw me some info/advice on how to proceed?

 

[akatagyourit]

Took cylinder head back and they replaced all lifters and re ran all tests and it passed with flying colors. Reinstalled today and immediately ran compression test again. All cylinders are now 190 except cylinder 2 which is still at 90. Attempted to finish installing everything to start the truck and let it run through a few heat cycles to see what happens. Ran out of light and mosquitoes almost carried me off.

 

[tomw]

That's good news. Better than having to take the block apart.

It made little sense that the rings in one cylinder would fail and leave the others intact as they are all given approximately the same conditions of temperature, lube, etc. Odds were not in favor of ring failure. At least that was what I was thinking.
My bet is you had one or more lifters that were jammed, and oil pressure was not enough to un-jam the internal parts. I have no proof, but the followers should all have been 'tight', and have very little if any movement.(when both valves were closed)
The Lima lifters don't give a lot of problems, so you must have run into some unusual condition. Too bad you had to repeat the work, but it's done now and working.
tom

 

[akatagyourit]

Unfortunately its not Tom. I got everything installed and did another compression test. I'm still showing 90 for cylinder 2 while the other 3 cylinders have gone up to 190. I fired the motor up and the valve noise appears to be gone, but i'm guessing I have bottom end noise at this point.

Here is a little video of the sound.
https://youtu.be/4Y4jzq9X3j8

 

[tomw]

Once again take off the cam cover. Crank the engine around slowly so you can bring #2 to TDC. While sitting, push on the intake & exhaust lifter supports. You should be able to collapse them after giving them constant pressure. If you cannot collapse the lifter(s), then the valves will be kept open, possibly just a smidge. You should be able to get ~.050-.060" clearance with a collapsed lifter. (it will TAP when you go to restart if you do get clearance as it gets refilled with oil) If you cannot get clearance, your valve is likely not seating. This could be caused by a bum lifter(jammed/badly machined/???) or by a valve that has had its seat recessed, was ground, and the stem stuck up out of the head even more than normal. There is a spec for the 'installed height' of the valve in the head given by FoMoCo. I do not know it. If the stem sticks up too much, the clearance will be eliminated, and the valve not seat. Fix is to put in new seat(s), or shadetree, grind the tip of the valve stem to allow a bit shorter 'length' in the valve train.
tom
My computer is not liking youtube today, so I did not listen/see your vid.