compression
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Mountain Pass
Joined: Jan 2001
Posts: 130
Likes: 0
From: Ozark Arkansas
compression
i checked my compression today and it doesnt look to good.here what i got
1 95lbs
2 100lbs
3 105lbs
4 75lbs
5 110lbs
6 110lbs
7 100lbs
8 75lbs
im not to sure what to do about it plugs still look new and they have been in there for 15000 miles. not a drop of oil on them.
1 95lbs
2 100lbs
3 105lbs
4 75lbs
5 110lbs
6 110lbs
7 100lbs
8 75lbs
im not to sure what to do about it plugs still look new and they have been in there for 15000 miles. not a drop of oil on them.
Freshman User
Joined: Feb 2002
Posts: 35
Likes: 0
From: Joplin
compression
[updated:LAST EDITED ON 03-Mar-02 AT 03:34 PM (EST)]If the pressure ISN'T bleeding off, it could be worn parts in your valve train. (lifters, cam, rockers, pushrods..etc) If an intake valve closes too soon or too late it will throw your compression off.
Just a suggestion; but, if it's running ok I'd wait a while to mess with it....strictly up to you. I tend to procrastinate. LOL
X17
Chevy Trucks, like a rock!
Yea, like a flat rock!
easy to break and won't roll.
Dodge Trucks, the rules have changed;
so they could win!:-
Just a suggestion; but, if it's running ok I'd wait a while to mess with it....strictly up to you. I tend to procrastinate. LOL
X17
Chevy Trucks, like a rock!
Yea, like a flat rock!
easy to break and won't roll.
Dodge Trucks, the rules have changed;
so they could win!:-
Thread Starter
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Mountain Pass
Joined: Jan 2001
Posts: 130
Likes: 0
From: Ozark Arkansas
compression
im starting to wonder if the timing chain may have jumped a tooth. b/c it wont idle right. and has lost quite a bit of power. i read today that this can cause low compression. btw it is a 84 f150 351w
Freshman User
Joined: Feb 2002
Posts: 35
Likes: 0
From: Joplin
compression
could have skipped time; but the compression should be consistently low in all cylinders, a sloppy chain will do the same thing.
One thing you can try, is adjusting your collapsed lifter gap (distance between the end of the valve and the rocker arm). Used to be called valve lash..lol before hyd. lifters
My manual says you should have .112 to .172 clearance on your 351 w. BTW you will need a special little tool to compress your hyd. lifters...unjless you know a shortcut. You will also need to rotate (just like valve lash) the crank for each piston and valve combo to be in correct position.
If your system is not overly worn and the valves don't leak this should fix your problem without having to take half the motor apart.
let me know how it turns out.
good luck.!
Chevy Trucks, like a rock!
Yea, like a flat rock!
easy to break and won't roll.
Dodge Trucks, the rules have changed so they could win
One thing you can try, is adjusting your collapsed lifter gap (distance between the end of the valve and the rocker arm). Used to be called valve lash..lol before hyd. lifters
My manual says you should have .112 to .172 clearance on your 351 w. BTW you will need a special little tool to compress your hyd. lifters...unjless you know a shortcut. You will also need to rotate (just like valve lash) the crank for each piston and valve combo to be in correct position.
If your system is not overly worn and the valves don't leak this should fix your problem without having to take half the motor apart.
let me know how it turns out.
good luck.!
Chevy Trucks, like a rock!
Yea, like a flat rock!
easy to break and won't roll.
Dodge Trucks, the rules have changed so they could win
Senior User
Joined: Aug 2001
Posts: 352
Likes: 0
From: Denver USA
compression
Timing chain is likely to be pretty loose if you went over 150K miles without changing it. It'd be a good idea to change it anyways. The chain on my F250 was so loose that I probably could've taken it off without taking the cam sprocket off.
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