Compression test 01 Navigator

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stamp11127

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The idea is to determine the origin of the leak - more the better since it will be easier to hear.
Hear it in the intake it is an intake valve.
Hear it in the crankcase it is rings or hole in the piston.
Hear it in the tail pipe then it is an exhaust valve.

When you are turning the engine I hope you are using the bolt on the crankshaft/balancer and not the bolt on the cam sprocket. Snap either of those cam bolts off and you will add to a bad day.
 
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Fordgirl01

Fordgirl01

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The idea is to determine the origin of the leak - more the better since it will be easier to hear.
Hear it in the intake it is an intake valve.
Hear it in the crankcase it is rings or hole in the piston.
Hear it in the tail pipe then it is an exhaust valve.

When you are turning the engine I hope you are using the bolt on the crankshaft/balancer and not the bolt on the cam sprocket. Snap either of those cam bolts off and you will add to a bad day.

Oh no. I thought that was how I was supposed to turn it. I think I turned the wrong bolt. I will have to look again tomorrow. I didn’t hear anything snap and I wasn’t forcing it. I hope I didn’t do what I’m afraid I did.


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Fordgirl01

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Well I must admit I was pretty discouraged Monday and didn’t even want to touch anything yesterday! So I went to harbor freight after work and bought a compressor instead-not sure why I waited this long to get one. I put a constant air supply to the cylinder this time and there is definitely air coming from the tailpipe.

Also I turned the crankshaft pulley and the camshafts are turning-this is a good sign, right (after I turned the camshaft sprocket a couple times around by mistake last week)?! I turned it to get the piston down and let it start to come back up. I again stuffed maybe 3-4 feet of rope in there and poked it down in. I turned the crankshaft until the piston was at the top but still don’t feel it binding against the rope. Should I feel it stopping the piston or is it subtle enough I won’t really notice? I don’t dare try to take the spring off until I know I have the rope in there right! That valve is hard enough to get to-I don’t want to make even more work for myself by losing it.

Thanks again for sticking with me!!


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Fordgirl01

Fordgirl01

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I think I figured out my own question. I bet I am not getting the rope down into the spark plug hole. I think it’s
just wadded up in the deep well before the plug hole. I’ll try again this afternoon.


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TobyU

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Use a long skinny screwdriver or better yet a small wooden long dowel rod to feed it into the cylinder.
 
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Fordgirl01

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Hey girl,don't give up. We haven't given up on you yet. You've made it a lot further then some mechanics I know. Patience is a virtue.

Thanks for the encouragement. I’m still picking away at it. I was away last weekend so haven’t had a lot of time. I’m still not having luck with the rope trick. I did get it into the plug hole this time-about 12 feet of it. I think my next try I will use different cord. I think the parachute cord is maybe too squishy. Do the pistons on these have some sort of cupped area and maybe that is why I’m not able to feel it bind up? In the meantime, I keep hosing that valve with penetrant hoping it will miraculously pop free.

Yesterday I made an unsettling discovery though. I think I messed something up when I was turning the cam with the bolt on the camshaft and not the crankshaft. Yesterday as I was getting the piston to the top (I had the camera in there to watch it), something seemed off. Originally the lobe was at the top when the piston came up. Now it seems to be about 1/4 of the way off. The lobe is more at 9 or 10:00 instead of 12:00 if that makes sense. So I’m guessing this means I am going to learn how to rip into even more to remedy my mistake?

This is certainly a learning experience!! Like I said-I’ll keep at it of if takes me all year. I rarely have a whole day out there, so I just work at it when I can.


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Atman246

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So here's another question. When you look at the valves when the cam lobes are not on the follower,do the valves all look at about the same height? The follower is the piece that "fell" out. If they do,then the valve is in the closed position and likely bent or burnt. Either way,the head has to come off. If it's sitting down compared to the others,then you might still be looking at a broken/ bad spring. Can you get a mirror in to have a look? If it is sitting up,you might also try "popping" the valve by tapping on the valve stem. If you can get a piece of wood dowel or something onto the valve stem and tap it with a hammer. Might save you some time.
I think at that point,you'll have to decide if you just want to do the head and all the accompanying parts or maybe consider a used engine. My two cents. Good luck on your mission.
 
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Fordgirl01

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It looks lower than the others so it’s stuck open. Air leaks from the exhaust when I put air in that cylinder. I’ve been soaking it with penetrant and trying to pry and wiggle it around. It’s not in a spot where I can hit the end of it.
I’m going to try the rope trick again and I’m about ready to take the spring off even if I’m not sure the rope is actually bound up against the top. I have a feeling I’m going to have to get into it deeper anyway.


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Fordgirl01

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FINALLY!! I got the rope to bind up. I’m taking the valve spring off tomorrow to see if I can get the valve freed up.


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Atman246

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At this point,don't remove the spring and keepers. Get the valve closed and held up. The valve maybe binding which says to me it might be bent. If you have it pushed back up like the others,try putting the air to the cylinder again and see if you have leakage. If no leakage,look at the spring. Is it loose,or tight? If tight,the valve is the issue. Head removal.. If the spring is loose,then it's still just a spring issue and quickly fixable. Keep us posted. Good luck,you're doing an awesome job. You're making me proud. That's all I can say. Just as a side note,i have a 25 year old daughter that I'm trying to teach a little about automotive. She's trying,and that's the most important part. Good luck K. Take care,R.
 
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