My valve seals are leaking, puffs smoke on the first crank of the day but none after that unless it sits several hrs. I've never replaced valve seals or heads with a motor in the truck 88 5.7 . Trying to figure out which one is a faster fix? I know the seals are cheaper , but a good set of rebuilt heads are fairly cheap too.
CK5
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swapping heads v/s valve seals?
- Thread starter prolinews
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readymix
3/4 ton status
Valve seals are faster, cheaper and easier... if that's the only problem.
Really?..
I have done a few valve seal jobs and thought it was a tedious ,sucky procedure..your bent over for hours,praying you dont have a valve drop in the cylinder (I used nylon rope in the spark plug hole method,I had more than one valve slip down into the cylinder when using the compressed air method,and was lucky not to have to pull the head off to get it back up!)...by the time I was done, it took the better part of a day,I was sore and beat too...also lost a valve keeper on one valve and never did find it,I had to rob one off a boneyard engine to finish the job..
I think pulling the heads is about as much work,but it might be a better option,you can take them off pretty quickly,and do the seals on the bench faster and easier....usually by the time valve seals fail,there is a good chance one or more valves are burnt or need refacing..only trouble with doing even a "backyard" valve job by lapping them in by hand and checking for excess guide wear,is you risk having the rings start blowing by once its buttoned back up...I made a few engines that didn't smoke at all except on startup into ones that belched like a tire fire after a valve job...
..in the end,bolting in a better running used engine would have been less work and taken less time...
I have done a few valve seal jobs and thought it was a tedious ,sucky procedure..your bent over for hours,praying you dont have a valve drop in the cylinder (I used nylon rope in the spark plug hole method,I had more than one valve slip down into the cylinder when using the compressed air method,and was lucky not to have to pull the head off to get it back up!)...by the time I was done, it took the better part of a day,I was sore and beat too...also lost a valve keeper on one valve and never did find it,I had to rob one off a boneyard engine to finish the job..
I think pulling the heads is about as much work,but it might be a better option,you can take them off pretty quickly,and do the seals on the bench faster and easier....usually by the time valve seals fail,there is a good chance one or more valves are burnt or need refacing..only trouble with doing even a "backyard" valve job by lapping them in by hand and checking for excess guide wear,is you risk having the rings start blowing by once its buttoned back up...I made a few engines that didn't smoke at all except on startup into ones that belched like a tire fire after a valve job...
..in the end,bolting in a better running used engine would have been less work and taken less time...
79rustyk10
3/4 ton status
Unless it's consuming oil, I wouldn't worry about it myself, unless the heads are coming off for another reason.
black dawg
1/2 ton status
Depending on how many miles are on it, seals are a perfectly acceptable fix. Probably a 2-3hr job if you have never done it before.
Fill the chambers with compressed air and swap the seals. as long as you have a spring compressor you can do this pretty quick and easy..
4xcrazy
3/4 ton status
Mine did that for a long time, I let it go, it wasn't really hurting anything except for using a small amount of oil between changes, maybe a plug cleaning now and then, wasn't a big deal though, Mine had well over 200k miles until the head gasket finally failed at about 250k.
Didn't blow anything up, just started leaking a little bit until it just got to where it filled a cylinder with water one day. Rebuilt the whole engine.
Didn't blow anything up, just started leaking a little bit until it just got to where it filled a cylinder with water one day. Rebuilt the whole engine.
Yep. The right tools make all the difference in this job. Buy/rent a quality spring compressor. The crappy ones can sometimes slip at the worst moment, rocketing your valve keepers across the shop. An air hold for the cylinders eliminates the tedious process of the TDC+rope trick.
A head swap is less meticulous, but significantly more work, even if you're swapping on a pre-assembled head. Unless there's something wrong with the heads or you're upgrading, save your time and money. Also, if the engine is old enough to have leaking valve seals, it's a possibility (though by no means certain) that a strong new head with no leakdown and fresh parts may expose weaknesses in the lower end (worn rings, etc) which opens up additional problems.
My unfortunate experiences with valve stem seal jobs led me to think its better to just run the engine as-is, until it needed other work...the puff of smoke upon start up after sitting is only annoying more than anything IMO...at worst,it might foul a plug once in a while..
The fact one 350 I did stem seals on lost a head gasket just 2 weeks later,
,and the other engine I decided to just pull the heads off and do a "valve lap" and stem seal job --and had it smoke terribly afterwards,made me wish I'd just left them alone...
I found its not that bad to pull an engine right out of a square body rather than bend over it for a day or more--I had it down to about an hour and a half alone,to pull one out and have it hanging on the engine crane...something like a dozen bolts,a few hose clamps,some wires,and its out..nothing like the newer trucks after 1988 with EFI,etc..
The fact one 350 I did stem seals on lost a head gasket just 2 weeks later,
,and the other engine I decided to just pull the heads off and do a "valve lap" and stem seal job --and had it smoke terribly afterwards,made me wish I'd just left them alone...I found its not that bad to pull an engine right out of a square body rather than bend over it for a day or more--I had it down to about an hour and a half alone,to pull one out and have it hanging on the engine crane...something like a dozen bolts,a few hose clamps,some wires,and its out..nothing like the newer trucks after 1988 with EFI,etc..
With these older trucks it's often a toss-up on whether it's easier to pull an engine/transmission just because they're so easy to get at. My truck has a lift which can add to the frustration, most of the time I just climb into the engine compartment and work while sitting on the fender. My only hesitation about engine pulling is the hassle of lining that thing back up when it goes in, since I usually work alone.
As for valve seals, a little oil from bad seals isn't a major problem. Depending on personal experience and motivation, sometimes you have to weigh your options, and at times let that sleeping dog lie. I'm kinda picky about my truck running as well as it can, but I can see the cost/benefit calculation not paying off for many.
As for valve seals, a little oil from bad seals isn't a major problem. Depending on personal experience and motivation, sometimes you have to weigh your options, and at times let that sleeping dog lie. I'm kinda picky about my truck running as well as it can, but I can see the cost/benefit calculation not paying off for many.
I just talked myself into believing the additional "upper cylinder lubrication" was actually GOOD for the engine,no more "dry starts!"...
...
I agree working on lifted trucks does suck...unless your working UNDER it!..
I use a trick my friend uses at his shop when he works on trucks that are high from the factory,or lifted--he just takes the front wheels right off,and lowers the brake rotors onto the ground,with some wood blocks under them,,that makes it much easier to work under the hood...
I haven't owned any lifted trucks,other than my old '77 K2500,it had some cobbed up lift kit when I bought it that consisted of some unknown brand of 6" lift front springs that evidently didn't belong under a GM truck,and some tall blocks in the rear,and a home brewed 3" body lift made of solid aluminum blocks ...I hated the way it drove,rode,and handled,it felt "dangerous" and it was,thanks to everything being a hack job..it also had what looked like a home built steering arm "block" to raise the draglink up...
I hated working on it,I couldn't reach the air cleaner nut,and I'm 6'5" tall!..had to climb up in the engine compartment and sit on the fenders to get at anything...I decided I wanted the truck back to stock,I was not impressed with it "lifted" at all,other than maybe looking a bit cooler...
I left the body lift,but took off the front springs,rear blocks & U-bolts,the 4 nearly bald 36" Dick Cepek tires and the ratty chromed super wide rims,and a custom made "air tank" front bumper ,sold them all for 400 bucks,and bought some 3 leaf stock front springs,new U-bolts,and 4 "new take offs" 8 lug Ford rims with like new 235-85 tires a guy was selling for 100 bucks at a yard sale not far from my house,after his wife bought him 4 new tires and rims for Xmas...
My truck went from a too tall,wobbly,shaking, vibrating POS you were scared to drive over 35 mph,to a blissfull near stock smooth riding useable truck...after that I never wanted to own one that was lifted,not for daily driving purposes anyway..
...I agree working on lifted trucks does suck...unless your working UNDER it!..
I use a trick my friend uses at his shop when he works on trucks that are high from the factory,or lifted--he just takes the front wheels right off,and lowers the brake rotors onto the ground,with some wood blocks under them,,that makes it much easier to work under the hood...
I haven't owned any lifted trucks,other than my old '77 K2500,it had some cobbed up lift kit when I bought it that consisted of some unknown brand of 6" lift front springs that evidently didn't belong under a GM truck,and some tall blocks in the rear,and a home brewed 3" body lift made of solid aluminum blocks ...I hated the way it drove,rode,and handled,it felt "dangerous" and it was,thanks to everything being a hack job..it also had what looked like a home built steering arm "block" to raise the draglink up...
I hated working on it,I couldn't reach the air cleaner nut,and I'm 6'5" tall!..had to climb up in the engine compartment and sit on the fenders to get at anything...I decided I wanted the truck back to stock,I was not impressed with it "lifted" at all,other than maybe looking a bit cooler...
I left the body lift,but took off the front springs,rear blocks & U-bolts,the 4 nearly bald 36" Dick Cepek tires and the ratty chromed super wide rims,and a custom made "air tank" front bumper ,sold them all for 400 bucks,and bought some 3 leaf stock front springs,new U-bolts,and 4 "new take offs" 8 lug Ford rims with like new 235-85 tires a guy was selling for 100 bucks at a yard sale not far from my house,after his wife bought him 4 new tires and rims for Xmas...
My truck went from a too tall,wobbly,shaking, vibrating POS you were scared to drive over 35 mph,to a blissfull near stock smooth riding useable truck...after that I never wanted to own one that was lifted,not for daily driving purposes anyway..
I think I'm gonna bite the bullet and let a shop do it. I have no idea how many miles are on the engine but it seems like a solid motor. I know at one point in time it's been swapped . It smokes like a freight train on first start up but none after that. Even under hard acceleration no smoke. I hate to let anyone turn wrenches on my stuff but some things just seem like a PITA. In the last few weeks I've rebuilt the transfer case on my DMAX, converted the k5 over to new style freon new compressor fixed leaks, rebuilt and modded a tbi for it. On my wifes car swapped in a new alternator freaking all day job from hell (zx4 focus),new valve cover gasket and serpentine belt . I'm gonna take a break and spend the coin
4xcrazy
3/4 ton status
Pull the heads, put some new head gaskets in there while having the heads serviced and resealed.
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