peow130

Well, gents, i've done everything i can possibly do short of pulling the head again.

There's a VERY noticeable valve tap/knock/rattle at a certain RPM, at a certain position of the skinny pedal, in any gear.

This is only noticeable at one specific RPM.. Above and below, it just sounds like a noisy valve-train.

Adjusted the valves today when the engine was warm to spec (they were just slightly above on each valve).. .008 intake, .012 exhaust.
No change in aforementioned valve rattle, no change in valve noise level.

Does have an exhaust leak between the manifold and head, but i know this isn't the cause of this noise.

Valve cover is NOT On too tight.

http://www.youtube.com/watch?v=lV3B724B88U&

Truck has 261,000 miles, but i know that the motor is probably pushing around 140k. The beginning of this year, i replaced the t chain, t chain guides, the timing chain tension-er, head gasket, etc etc. Prior to this, the valve noise didn't exist. It was only until the temperature dropped last November. Around this time, an off-idle hesitation started to occur. I don't know if maybe these are hand-in-hand.

No amount of premium fuel, idle adjustments, carburetor cleaner bottles, or anything has affected the off-idle response.

Thicker oil didn't do anything with the valve tap.


tl;dr Valves WAAAYYY too noisy, nothing has helped, i'm starting to fear the worst. Help please.

peow130

60 Views, nobody has ANY ideas?

I'm about to just bite the bullet and buy a new head from engnbldr, but i'd like to not have to do that until i have another vehicle to drive

superex87

Your valves are so noisy because they are too loose!!!
There is a typo in the fsm! Your supposed to adjust the valves with the engine COLD!

Think about it like this...

When the valves get hot they expand
The reason there is an adjustment spec is so when the valves expand you dont have a valve that is open all the time when it is hot = burnt valve

When you adjust the valves when they are cold on the exhaust side to lests say .012, the valve heats up and expands and the gap then becomes something like .002 ish
That's why on an engine with properly adjusted valves you can barley hear them, there is very little gap when the engine is warm.

But when you adjust them with the engine HOT, the hot spec is .012 and th cold spec becomes like .02! way too loose.

peow130

seriously?
i guess i'll wait an hour and try again?
Could it possibly be a spun bearing?

I think i might try and find a good core and build it up this spring.. We'll see.

skypilot

iTrader: (1)

Nope; a spun bearing will tell you in other nasty ways. Look at the cam lobes and see if they are cutting the top off. I had one valve that tapped a lot, and its the cam that was failing along with the valve not wanting open all the way.

peow130

Ill check again tomorrow when I pull the valve cover off. I also bought new plugs, the old ones look uh... Interesting

96vettelt4

I have found many times the fan coming into contact with the shroud will make a ticking noise similar to that as a valve tap..I would turn the fan by hand to see if it comes into contact..worth a look..also do need to make sure valve lash is correct....G

peow130

Adjusted the valves cold to .007 intake and .011 exhaust.. Slightly quieter, but now a different noise.

http://www.youtube.com/watch?v=pBxuAOKaIzg&feature

Dunno what else, I'm losing oil somewhere, too. It's not leaking out the bottom of the oil pan, and it doesn't seem like i'm burning any.

Here's a picture of the old plugs. Bosch Platinum 2's, maybe 20k miles on them.

peow130

Adjusted the valves cold to .007 intake and .011 exhaust.. Slightly quieter, but now a different noise.

http://www.youtube.com/watch?v=pBxuAOKaIzg&feature

Dunno what else, I'm losing oil somewhere, too. It's not leaking out the bottom of the oil pan, and it doesn't seem like i'm burning any.

Here's a picture of the old plugs. Bosch Platinum 2's, maybe 20k miles on them.

skypilot

iTrader: (1)

you are burning oil. the plugs tell no lies.

peow130

Yeah, i've burned about a quart and a half in about 1,000 miles. Last oil change or two i've noticed that the oil smells heavily of gasoline.

I'm about to just sell it and get out from under this carrot before it gets too deep.

peow130

Went back outside, started it up, it's knocking from either the 1st or 2nd cylinder..