2005 Tundra 4.7L Dead Hole

Hello! I have a 2005 Tundra 4.7L with ALOT of miles. Over 300K. Very well maintained truck tho. Truck died driving down the road. Let it sit for a while. Got it started but was missing really bad. Multiple cylinder misfires on my scan tool. I pulled the timing covers. Belt is in Bad shape but my timing marks still line up. I pulled all the coils and plugs. Coils are in bad shape most of them are cracked.

Thought I better do a compression test before I went any further. Got to #7…… 0 psi compression. Sprayed some WD40 in the cylinder, still none. Pulled the valve cover. I found one of the Intake valves stuck open. Question is, do these things break valve springs or do I maybe have a bent valve? Weird thing is when I bring the cylinder up to TDC and put air into the cylinder it does Not leak out through the Intake.

 

Never heard of either but you should be able to see if the spring is broken if you have the valve cover off.

 

Really can’t see much.

 

Follower looks "stuck" down.
Can you take a magnet an see if the follower moves?
Kind of wondering if its a stuck follower in a bind?
Maybe you can get lucky if the follower is stuck. Try to press down on it and see if it pops back up?

I mean, that's not the best idea. As you really haven't fixed anything.
And the follower could get stuck again, but I'm lazy. I try easy stuff first.
You're likely going to have to pull the camshaft anyways. I say "try something".

 

Ah I see, I'd do as @TnShooter suggested. Worst case you gotta pull the cam & bucket and see what's going on.

 

I don’t know what’s going on with your valves but if most of your ignition coils are cracked I’m surprised it was still running. I would expect it (if still running) to be missing and vibrating like crazy. Could cause valve damage too ,and could damage 02 sensors. The damaged ignition coils could be the root cause of all your problems. In any event you need a new timing belt, new ignition coils and who knows what else with the valves/ cam. 19 year old truck with 300000+ miles and serious mechanical issues I’d be looking at selling it as is or when repaired.

 

Welcome to TW.

 

On this note, I have seen valve seats fall out. Causing the intake/exhaust valve to stick open. On the 1GR. (I have also seen bolts do the same. )

If the magnet doesn't help, then something is holding the valve open.

 

I tried a magnet, wouldn’t move. Then I tried tapping on it with a small brass drift, still stuck. I guess I’m pulling the camshaft.

 

If you need service data to put it back together, let me know.
I feel for you man. But at least you're willing to try it yourself.

 

I'd probably find a borescope and take a look into the cylinder.
If the follower is "stuck", it's going to be hard to get it "unstuck" even with the cam out.

What I'm trying to avoid saying is, The head might have to come off.

 

The valve is bent or the seat dropped. Either way the head has to come off

 

Yeah, and on a 300k mile engine.
Decisions....decisions.....

 

I would be totally surprised it it wasn't one of those two things.

 

Ok. I finally got back to this. I used a boroscope but I couldn’t see a whole lot. It doesn’t look like the valve hit the piston. So I did some research. Book time for one head is 16 hours . Or 20 hours to remove and replace the engine. Does a guy just bite the bullet and put a used motor that will still probably need a timing belt?? I wonder how bad this one would run if I put some new coils on it? Thoughts?

 

Hello! I’m back! Finally decided to move forward with fixing the Tundra! I pulled the motor out and shipped it out to be rebuilt. I just got it back and week ago and it looks great! One hip-cup tho, I sent it out with the timing belt and water pump still on it. They sent it back with all that stuff in a box. Whoops. I have a timing belt/water pump kit so I’m not too worried about it. There’s just a couple parts I can’t seem to figure where they go. The 2 aluminum washers/spacers and the Allen bolt. I’m gonna send this picture to the engine rebuilder also. Thanks in Advance!