Fx4Mark

I have a 2005 F150 FX4 with the 5.4 with 214000Km. The truck was idling really hard, only at idle and lacked power, figured it was the phasers or VCT on the way out. Had the engine light come on saying Cylinder 2 misfire. Changed the plug and Coil twice no change. I did a compression test and got 40psi in #2. All my other cylinders are getting 180psi. Pulled the valve cover yesterday figuring it would be a broken spring or a burnt valve. Here is where it gets weird...... when i turn the engine over by hand with compressed air going into the cylinder with a leak down tester I’m getting 80% loss at top dead center and threw the entire stroke. but there is no air coming out the exhaust or the intake or the oil dip stick or the coolant bottle. One more thing as the camshaft was turning it didn't appear to open the valves. Every other cylinder you could hear the hissss as the valve opened but not #2. i'm assuming it's the camshaft, or the roller followers causing the valves not to open but where could the air be going?? I'm starting to assume that its the rings on the piston but should i not hear air from the dipstick? Anyone have any ideas what could be going on??

Thanks!
Mark

06AriBei

When you bar the engine over, watch again and see if they open and close. If they don't open or close your camshaft lobes could be fully worn. Wouldn't be a bad idea to check the with a feeler gauge as well and compare it with all the others and what spec is. If you have worn rings there should be air coming out the dipstick but it should also vent out of your pcv. You should rent a borescope and inspect cylinder #2.. Make sure to rent one that the tip articulates so you can inspect the valves.

Especial86

iTrader: (1)

Sounds like a seized valve lash adjuster and possibly a bad or seized wheel on the cam follower.. Good thing you caught this now because you will undoubtedly drop a valve which will basically end any easily repairable life of the motor..
Lash adjusters should be swapped out every 200k miles, they are a wear item..
If there's any accelerated wear on the cylinder 2 cam lobes than this would be the sure sign of seized roller followers and lash adjusters..

Pics always help..

scobar

iTrader: (4)

133k miles. If the valves are not opening/closing and it is turning over w/o much of a fight and with the loss of cylinder pressure, how about rings? Could try to drop some oil down the cylinder wall and try compression test again?

Fx4Mark

Pulled the heads today and found what the problem was. I couldnt hear the escaping air because it was all coming out straight out. Note to self put your hand over the exhaust pipe and don't rely on others to tell you there's nothing!


the exhaust.

Burnt valve

Rick's 06

That would explain your loss of compression, but what about the valves not moving? Maybe they really were and you just couldn't see them. Regardless, now that you're this deep into it, what all are you going to replace?

Fx4Mark

Since I'm this far in I'm replacing both head gaskets, timing set, phasers, vct solenoids , both exhaust manifolds on the bench , spark plugs and more then likely all the lifters when I press on them they are rock solid. But I did notice some scoring in the cylinder bores from 1 to 4 they are consistent I'm not sure if this is normal. I'm not losing compression in the others so... I don't want to leave it but.... I'm leaving well enough alone. I'll post a picture later today when I'm back there

vintageman

Glad you got the head removed and found the burnt valve. At this point, since the head is off, I would change the valve seals as well, it shouldn't take long. I just did that on my motorcycle a few months ago. I cut a piece of 1 inch PVC pipe and put a good notch in it, got a big C Clamp, put the pvc pipe on top of the valve and used the c clamp to compress the valve spring till the valve retainer clips just popped out. Removed the valves and springs (keep them in the right order because they need to go back into the same valve guides). Once I got the valves all out, I cleaned them all, cleaned the head real good, then changed the valve seals, got me some grinding compound to use on the valve and valve seats and put it all back together. Make sure if you do any of this or just change out the one burnt valve (changing out the one burnt valve should also require you using the valve grinding compound then cleaning it), that you do a Leak Down test while the head is still off. Good luck. Keep us in the loop on what you decide to do.
Tom

Fx4Mark

Thanks VintageMan! I'm sending the heads to the pro's i'm doing this one time, and one time only! Next time it will be an engine swap haha If you ever need to do this, here are a few words of advice! Pull the engine!!!!! And if you can't at least don't listen to my local ford service people, and let them tell you you don't need to drain the A/C do it! it will make life much easyier! I bought all the tools i think i will ever need to work on this engine the wedge tool, the broken spark plug tools, the timing tool, the spring compressor, camphaser lock tool (came with the wedge tool) these engines are not bad to work on it's just that everything is in the way and your taking everything apart but lets all be thankful it's not a VW!

vintageman

Yea, you're right there, everything is in the way when you gotta do work on these engines. Good job getting the head off, let us know how it goes.

Tom