As I stated in my Hello to everyone, I removed the left cylinder head on my 97 F-150 4.6L (windsor engine). In all it took about 20 hours with some beer drinking here and there. Now that I've got the broken exhaust valve fixed, I was wondering which bolts, if any, need RTV sealant or locktite put on them when I put them back in?
FYI, I had to remove the intake, left valve cover, exhaust manifold, water pump, timing chain cover and of course the head. I do know about the little dabs of RTV needed at the intersections of the different gaskets on the oil pan, valve cover, and timing chain cover.
Thanks guys, info on these pages helped me out a lot!

 

I am not so sure about locktite or RTV on the bolts themselves, but anti-seize and torqing to specs should cover you. Otherwise, you may not be able to remove them cleanly if you have to do it again.

Anyone else want to chime in?

 

I hate to jack my own thread, but.............
I got it all back together and fired her up and still very little compression in #8 cylinder even after replcing a cracked exhaust valve. I'm now going to try and find TDC of this piston and pressurize the cylinder with air to listen for the leak and find where it is. Does anyone have any hints about finding tdc without removing the valve cover to check position of the valves? I've also heard of the cam shaft lobes slipping on the shaft and throwing off the timing in a cylinder, anyone else heard of this? The shop that replaced the exhaust valve for me is shocked that I'm doing any work on this motor, as it only has 70,000 miles on it and thinks that maybe the camshaft is to blame for all this, by running the cylinder to lean and burning the valve. Any thoughts or other experiences on this?

 

To find TDC on this cylinder: Remove plug, insert a rubber hose that will fit tightly in the plug bore, insert thumb or other appendage into end of hose, rotate engine by hand until you feel pressure build in cylinder, pull hose out of bore and insert a dowel or similar soft non-damaging probe through spark plug hole and rest it on top of piston, continue turning engine by hand till dowel stops moving upward, you are now at TDC for that cylinder. This is my backyard method, it is accurate but there may be other easier ways. Did you check the valvetrain carefully before reassembly?

 

Valvetrain was inspected, the intake valve was open at the time I locked the cam in place and it looked ok. I also marked, with paint, the cam and chain in three spots and didn't remove the chain from the crankshaft sprocket and zip tied it in place so it wouldn't come off, so the exhaust valve was the only thing changed.
Now after applying air to the cylinder I get air coming out the intake all the way though the powerstroke but no air comes out of it on the exhaust stroke???? and the timing is fine in all other cylinders on this bank. Which takes me back to the camshaft lobe for the intake moving on the shaft, Am I just unlucky or has this happened to anyone else, or am I missing something in my logic?

 

Sounds like the intake isn't closing all the way, could be a bent valve, valve seat problem or your suspected cam lobe.
Probably the only way to narrow it down would be to pull the cam again and then do your pressure test. Both valves should be closed and any air leaking should point to the offending valve aasembly, if it is leaking that is......

Good luck
Volfandt

 

Thanks for the input, my plan is to pull the head again and replace intake valve and check camshaft against a new one for differences.
ILYK

 

Well I took the valve cover off this morning and found that my three paint marks on the cam sprocket and chain had moved over about 2 or 3 links As far as I've read the timing chain should ride on the same sprocket cogs every rev or else the timing mark on the sprocket and the special link would get out of whack...right? What would cause it to jump like this? It's probably the way I put it together but as I said before I left the chain on the crank sprocket and lined up my paint marks on the cam sprocket, shouldn't this have worked?
Thanks

 

well I'm embarrased, the intake valve is bent, and while taking the compression on every cylinder I noticed my paint on the chain and cam sprocket came back into line after who knows how may turns of the crank. Guess I shouldn't have cheaped out and just had the broken exhaust valve fixed, but hey it was obviously one of the compression leaks!

 

Better to find out now when the engine is apart rather than 20 miles after you've put everything back together