I have a F150 with the 4.6 (vin 6) and I'm having a hard time figuring out an issue. My timing chain guides and tensioners started disintegrating and the debris clogged my oil pump pickup. I got everything cleaned up and put back together with a new oil pump,chain guides, tensioner arms, tensioners gaskets, and even a new power steering pump.
Now the engine won't crank and when I try to turn it over with the balancer bolt, I can only move it maybe 10 or,at most,15 degrees before it stops. It's like there's a TDC stop installed but there's not.
I'm in the process of tearing this back down until I find the problem but if you have any suggestions about the problem I'd love to hear them.
I'm no mechanic but I'm pretty good at taking things apart and putting them back together all the while figuring out what the problem is. Unfortunately most of my experience doing that has been with much older engines.
Any help would be greatly appreciated.

Jimmy

 

Sounds frighteningly like valve timing is out of phase with crankshaft. Did you position the engine at TDC #1 with crank timing mark at proper position before teardown, or did you set the crankshaft sprocket timing mark in the proper position (6 o'clock) - and the cam sprockets & chain marks for R (drivers side) & L are lined up - while cam lobes were OFF both valves on #1 (compression stroke) and between exhaust closing and intake opening on #7, thus lining #7 up to fire on the next full 360 degree rotation of the crankshaft? I think the engine in this YouTube link is the same as your engine.


Good luck

 

I originally thought along those lines too except that it's happening independent of the valve train.

 

Well now I'm thoroughly confused. You first said "I got everything cleaned up and put back together with a new oil pump, chain guides, tensioner arms, tensioners gaskets, and even a new power steering pump. Now the engine won't crank and when I try to turn it over with the balancer bolt, I can only move it maybe 10 or, at most,15 degrees before it stops."

Now you say "except that it's happening independent of the valve train." How is it happening independent of the valve train. I thought you put it all back to together?

How then is ANYTHING happening independent of the valve train?

 

The 4.6 is an interference engine. If the valve timing is off the pistons will contact the valves, locking it up.

 

I took the timing cover back off to see if I had the chains off a tooth or so and slid the sprockets off the crank to see if it would turn.
Oil pan's off as well and nothing underneath is causing it so I believe glc has given me my answer.
On a good note, considering all the trash that ended up in my oilpan and oil pickup, the cylinder walls look really good from what I can see.

 

If you're looking at the cylinder walls from underneath - I'd say @GLC has given you the answer, and the solution is in the video in post #2. If you're looking at cylinder walls from the topside - I'd say you have left the transmission in GEAR.

 

Well tore it back down and thought it might be a good idea to have a look at the cam bearing surfaces. Scored all to hell. Kinda thought those would be made of steel but not so. The more I get into this motor, the less impressed I am with it. Although, considering the materials used, I guess 188,000 plus miles ain't too bad. Anyone know what the adaptability is of a 351 windsor or clevland engine into a 2002 is? I'm pretty much over a Triton motor and would rather switch to one that has more iron and steel in the critical parts.

 

You are pretty much locked into a Triton, a Windsor swap is far from easy and you would also need a different transmission, bolt patterns are different. Electronics are also a can of worms. The 4.6 is one of the most reliable engines ever made, if you didn't buy yours new how do you know how well it was maintained? There are too many people out there who don't know what an oil change is.

A 5.4 swap is actually reasonably straightforward.

 

I'm just really frustrated with what I'm seeing as I get deeper into this engine. I'm still having a problem rotating the crank even with the cams out. With the bearing caps for the cams and the cam bearing surfaces trashed I'm looking at what? New heads? I've got a friend who works at a machine shop and I'll see if there's anything he can do with the parts but by the time I buy heads if that's what I'm left with, I might as well get another engine.
My opinion is that the inferior materials used in this engine are a major problem regular oil changes or not. If it wasn't taken care of before I got it then yeah, that's part of the problem but plastic and pot metal wear surfaces aren't building any confidence I have in what has been a strong line of trucks.

 

Well, there are documented instances of Tritons going 1 million miles without a rebuild. You got one that was ridden hard and put away wet. If the truck is worth it, just drop a Ford reman in, it will have a very good warranty.

 

Sorry I'm being pissy about this. Just been a long frustrating task and its wearing on me and my wallet. I'll get it and on the bright side, I'll have a bunch of new parts in it when I'm done.

 

If it's still unusually hard to turn with the cams out, might want to check the main and rod bearings.

 

Yeah that was gonna be my next thing to look at even though I really don't want to at this point. Figured it'd be a good thing to look at before I go through the trouble of pulling the intake and heads. If they're in good shape then I'll go for a new set of heads. Otherwise I'll probably just go for a replacement engine.