Write up on how to change valve stem seals?
#1
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Year: 1994
Model: Cherokee
Write up on how to change valve stem seals?
I've googled a bunch but just can't seem to find a detailed list on how to do this(with the head on).
I've never cracked open a valve cover and generally shy away from engine work.
Can anyone provide me with a link/pictures on this?
Thanks.
I've never cracked open a valve cover and generally shy away from engine work.
Can anyone provide me with a link/pictures on this?
Thanks.
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Year: 1997
Model: Cherokee
Engine: 4.0L
The valve stem seals are little hats made of rubber or plastic that slip over the valve stems inside of the valve springs and reduce the amount of blow by oil that gets from the top of the head into the cylinder through the valve guides.
A bit of additional information might help. How many miles on the motor? Why do you think the seals are bad? Is the head off or do you want to try this with the head on?
The only time I've ever done valve stem seals was if I was changing valve springs or totally cleaning up a head with at least a valve lap, if not a valve job.
If you're seeing oil smoke, when do you see it? Valve guide/seal issues will usually show up as a puff of oil smoke when shifting gears on a manual or when you get off the gas to decelerate on an auto. (And then it's probably worn guides as well.)
A bit of additional information might help. How many miles on the motor? Why do you think the seals are bad? Is the head off or do you want to try this with the head on?
The only time I've ever done valve stem seals was if I was changing valve springs or totally cleaning up a head with at least a valve lap, if not a valve job.
If you're seeing oil smoke, when do you see it? Valve guide/seal issues will usually show up as a puff of oil smoke when shifting gears on a manual or when you get off the gas to decelerate on an auto. (And then it's probably worn guides as well.)
#4
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Year: 1994
Model: Cherokee
I think it's the valve stem seals because it does it on initial start up and when left idling. It's very faint blueish smoke and it smells like oil. PCV has been cleaned/freshened up and the plugs look good/copper/rusti-ish color.
The only time I've ever done valve stem seals was if I was changing valve springs or totally cleaning up a head with at least a valve lap, if not a valve job.
If you're seeing oil smoke, when do you see it? Valve guide/seal issues will usually show up as a puff of oil smoke when shifting gears on a manual or when you get off the gas to decelerate on an auto. (And then it's probably worn guides as well.)
I don't think it's rings, as it's got plenty of power. I figured if I can purchase some 20$ seals and not hafta take the head off, this might be a good option for me.
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Year: 1997
Model: Cherokee
Engine: 4.0L
Having the head off would definitely make it easier, otherwise you need compressed air to hold the valves up while you removed the keepers & springs. $150 for a refurb sounds pretty good to me.
The not smoking under decel seems odd. That would be the highest vacuum point for the engine so, if it was drawing oil from somewhere it should be more likely to do it then.
Random thought. Looking into the oil filler cap hole, how clean does it look down there? Much visible sludge/crud buildup? I wonder if you may have a restricted oil return passage that is causing you to hold too much oil up on top of the head? (Unlikely, but who knows.)
How much oil volume does it tend to go through under "normal" conditions?
The not smoking under decel seems odd. That would be the highest vacuum point for the engine so, if it was drawing oil from somewhere it should be more likely to do it then.
Random thought. Looking into the oil filler cap hole, how clean does it look down there? Much visible sludge/crud buildup? I wonder if you may have a restricted oil return passage that is causing you to hold too much oil up on top of the head? (Unlikely, but who knows.)
How much oil volume does it tend to go through under "normal" conditions?
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Year: 1997
Model: Cherokee
Engine: 4.0L
Since all the plugs are the same color, it does sound like an intake side issue. You said you've gone through the PCV system. Is there evidence of any oil in any of the other vacuum connections on the manifold that you've seen?
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Year: 1994
Model: Cherokee
PCV system/hoses look clean. No sludge, no soot. I've checked the dipstick and after 2,000-ish miles it still reads just about where it did when I did the oil change.
When I say it's smoking, I mean it's smoking just enough for me to notice. It's not some huge cloud. It's more of annoyance to me than I think anything. It aggrevates me that the rear main is leaking, but it will only leave a tiny thumbtack head sized spot on the ground if I let it sit for 4 or more days.
Again...been told "it's just a Jeep thing", but i'm just aggrevated by little things like that.
When I say it's smoking, I mean it's smoking just enough for me to notice. It's not some huge cloud. It's more of annoyance to me than I think anything. It aggrevates me that the rear main is leaking, but it will only leave a tiny thumbtack head sized spot on the ground if I let it sit for 4 or more days.
Again...been told "it's just a Jeep thing", but i'm just aggrevated by little things like that.
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Year: 1997
Model: Cherokee
Engine: 4.0L
Boy, that is a pretty minimal amount of smoke.
Thought on your rear main. I changed the rear main in my daughter's 4.0L Grand Cherokee. It had a MASSIVE leak running out of the front of the trans. It was NOT the rear main.
Turned out to be the valve cover gasket. Could have saved myself about 4 hours work by figuring that one out sooner.
Also, what weight oil are you running? Have you tried a higher viscosity to see if that stops the smoking?
Thought on your rear main. I changed the rear main in my daughter's 4.0L Grand Cherokee. It had a MASSIVE leak running out of the front of the trans. It was NOT the rear main.
Turned out to be the valve cover gasket. Could have saved myself about 4 hours work by figuring that one out sooner.
Also, what weight oil are you running? Have you tried a higher viscosity to see if that stops the smoking?
#11
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Year: 1994
Model: Cherokee
I put in some 10w40 Motorcraft Synthetic blend. It was 10$ for 5 quarts(and yes I added another quart to make 6 total). I also used a Motorcraft FL1A filter.
I added some RESTORE for the hell of it as it was on sale for like 5 bucks. It didn't really reduce the smoke that much. Or if it did, I couldn't tell.
My rear main is definetly my rear main. I had a massive valve cover gasket leak(again, that leaking thing that I hate). I retorqued all the bolts and then degreased the whole motor and it's dry as bone on top now.
I've also ran a can of Seafoam through the intake side. Didn't seem to run/idle any better afterwards.
I added some RESTORE for the hell of it as it was on sale for like 5 bucks. It didn't really reduce the smoke that much. Or if it did, I couldn't tell.
My rear main is definetly my rear main. I had a massive valve cover gasket leak(again, that leaking thing that I hate). I retorqued all the bolts and then degreased the whole motor and it's dry as bone on top now.
I've also ran a can of Seafoam through the intake side. Didn't seem to run/idle any better afterwards.
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Year: 2001
Model: Cherokee
Engine: 4.0
They make an air hose adapter that screws into the spark plug threads. Pressurize one cylinder at a time with a good air compressor, remove the valve spring. Push the new seals on and re-assemble...Good luck
#13
I prefer to fill the cylinder with nylon rope, rather than use the air fitting. Done it many times with no trouble. Will also say a small magnetic pickup tool helps remove retainers without losing them.
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Year: 1989
Model: Cherokee
Engine: 242
The cheapest I've been able to find a rebuilt head for was $330. I ended up pulling the head to exchange it for a junkyard head, but replaced the valve stem seals before installing the "new" head. It was a very easy job. Pulling the head was about a 3-4 hour task and allowed me to change out a few other things while in there (fuel injector seals, thermostat, etc). If you can swing the head job, go for it.
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