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3.0L 2003 Ranger 3 cylinders Misfiring i need some help please


No compression is very odd. Low - yes. None - most unlikely unless it broke a piston, valve spring, or the like but check the other cylinders as well as suggested.

By the way, 16 is a great age for doing all this. You can crawl in there, under there, etc. and not pay for it like us old geezers.
:LOL: right at this point imin it to get my truck running right again and to get the experience putting full engine rebuild on my resume would be great also old is good because age comes with wisdom and knowledge
 
You may get lucky and it's just a broken valve spring or a loose rocker arm.
If you are unlucky, it dropped a valve (valve broke and the head of the valve is on top of the piston). Or it bent a valve (usually means the engine injested something). Or bent a pushrod (but then why?). I would remove that valve cover and inspect. You can take pictures and post them, carnage is appreciated here 😉. Hopefully you don't have to pull the head or engine. 3.0 is a great engine, not much goes wrong with them.
 
You may get lucky and it's just a broken valve spring or a loose rocker arm.
If you are unlucky, it dropped a valve (valve broke and the head of the valve is on top of the piston). Or it bent a valve (usually means the engine injested something). Or bent a pushrod (but then why?). I would remove that valve cover and inspect. You can take pictures and post them, carnage is appreciated here 😉. Hopefully you don't have to pull the head or engine. 3.0 is a great engine, not much goes wrong with them.
that's what i am saying but of course this happens to me i am thinking its a spring or rocker because i here that continuous clicking and not like a tinging like a valve is bounding around in my combustion chamber also i will send some pics of my previous repairs on her that i did in the mean while. and when this happened i wasn't pulling any shenanigans i was just driving normally on the highway so it has to be spring lifter or something like that.
 
I don’t think I missed any posts, but just wanted to make sure everyone’s on the same troubleshooting page. You said you had 3 cylinders misfiring right? In that case you do realize that one broken valve/spring isn’t going to explain all the misfiring - you’ll be looking for multiple issues.
 
I don’t think I missed any posts, but just wanted to make sure everyone’s on the same troubleshooting page. You said you had 3 cylinders misfiring right? In that case you do realize that one broken valve/spring isn’t going to explain all the misfiring - you’ll be looking for multiple issues.
you are completely right but at this point i am focusing on the cylinder with 0!!! compression and while im in there i will look at 1 i don't know how i would look at 4 but if the problem persist i will look into that thank you for being the voice of reason :)
 
just to be clear.

zero psi.....anywhere.

pull cover.

hopefully something stupid.

had a valve on a 3.0 in a Taurus ride a piston for 15 or 20 minutes and while it did eat oil and smoke after we put the new used spring in it ...it ran ... for years....took a good 6 months before the cats required....help..

breathing.
 
Ok I pulled the valve cover today and found something very interesting the return spring for the exhaust for 3 has snapped and I believe that’s causing my issue now I must ask what to replace obviously the spring and valve cover gasket but should I replace anything else?
 

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keep digging.
check the pushrod for that rocker arm.
is it still in place???? is it bent? are the ends chewed up? it's hollow, oil flows thru it to lube the rockers.

the valve train is not adjustable. the parts are manufactured to fit properly so long as nothing is broken.
you simply bolt the rocker back on and tighten it down. the push rods should tighten up during the last turn, or two, of the rocker bolts.
that's the pre-load/lash.
have the valves ( camshaft cycle ) in a closed position when tightening them.

before you try to remove the spring retainer the valve must be secured so it won't drop down into the cylinder.
service manuals and others use compressed air thru the spark plug hole to keep the valves closed while servicing the spring.
that works, but I prefer to fill the cylinder with rope then rotate the crank to force the rope against the valves.
you can then leave the project for however long you need to.

it would be a good idea to look thru the pushrod hole to verify the lifter alignment bracket ( AKA dog-bone ) is still in place.
 
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keep digging.
check the pushrod for that rocker arm.
is it still in place???? is it bent? are the ends chewed up? it's hollow, oil flows thru it to lube the rockers.

the valve train is not adjustable. the parts are manufactured to fit properly so long as nothing is broken.
you simply bolt the rocker back on and tighten it down.

before you try to remove the spring retainer the valve must be secured so it won't drop down into the cylinder.
service manuals and others use compressed air thru the spark plug hole to keep the valves closed while servicing the spring.
that works, but I prefer to fill the cylinder with rope then rotate the crank to force the rope against the valves.
you can then leave the project for however long you need to.

it would be a good idea to look thru the pushrod hole to verify the lifter alignment bracket ( AKA dog-bone ) is still in place.
ok yeah the pushrod is still straight as an arrow and undamaged should i still replace it i know i have to replace the spring but should i also replace the push rod and rocker arm ?
 
if it's straight and the ends are not chewed up I would reuse it.
make sure its clean inside, quick squirt with anything.
check the rockers, if no damage reuse. they will have a wear pattern, 2 angled ridges from the pivots.

at this point try to pressurize the cylinder. if the valve was bent by contact with the piston it won't seal.
 
Roll the pushrod on a flat surface. If it's bent, it will be obvious. There are two ways to hold the valve from dropping into the cylinder. Most common is remove both rockers from that cylinder and feed compressed air into the spark plug hole. Another is pull the spark plug and feed clothesline into the cylinder, then rotate the crank by hand to compress the clothesline against the valve. I would replace that spring and then do a compression test on all six cylinders.
 
if it's straight and the ends are not chewed up I would reuse it.
make sure its clean inside, quick squirt with anything.
check the rockers, if no damage reuse. they will have a wear pattern, 2 angled ridges from the pivots.

at this point try to pressurize the cylinder. if the valve was bent by contact with the piston it won't seal.
right that what I'm afraid of but i believe i am just going to order a new valve cover gasket and spring and replace it and see what happens but you dont know how happy i was to see that spring and when i tell you its doing nothing anymore it is not doing anything i can really move that rocker arm around in there
 
Roll the pushrod on a flat surface. If it's bent, it will be obvious. There are two ways to hold the valve from dropping into the cylinder. Most common is remove both rockers from that cylinder and feed compressed air into the spark plug hole. Another is pull the spark plug and feed clothesline into the cylinder, then rotate the crank by hand to compress the clothesline against the valve. I would replace that spring and then do a compression test on all six cylinders.
ok that sounds good i have another question I'm on rock auto and there are different sizes and heights of springs and i am not too sure which one to buy
 

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