Good morning, at least for some of you I hope.

I'm getting blue smoke on start up and have been getting a top end knock that's getting worse. I'm betting the seals, guides and possibly the adjusters are going to need to be replaced.

Has anyone attempted this without removing the heads or the whole engine?

Engine is '99 SOHC, 5.4L, 160K miles.

Thanks for the help...

 

You have to take off the head to replace the valve seal, guides, etc; there is no way to get the valve out without removing the head. There is no reason to remove the entire engine unless there are more internal problems with the bottom end. Since you said you are having blue smoke come out the exhaust you make have a bad ring in some of the cylinders. I would do a compression test on all the cylinders and make sure they are in spec. If they are low or don’t hold compression then you need to replace the rings and or pistons etc depending on their condition.

 

not removing the valves, just the seals, guides, and adjusters. According to the book this can be done. Just not sure if there is enough clearance to get the spring compressor between the heads and the firewall.

Blue smoke is only at a cold start up, really don't think it's rings yet...

 

The book does say they can be replace them without removing the head, but I personally think it is better to remove and inspect the head for warping cracks etc, and the you can visually make sure the valves are seating properly.

 

true enough, but that calls for a lot more work than I think I'm willing to put into this. I saw somewhere that it's nearly impossible to pull the heads with the motor still in the truck. not worth sending to a shop for a $3K bill, for that kind of money I could buy a reman engine and drop it in there..

 

I have done seals on an MB inline six in the truck but, under the hood of the Expy looks like a nightmare. You would have to strip off a lot of stuff to gain decent access. I doubt the spring compresser is that big of a deal, they make a style that works with the heads on. I have never seen vavle guides that were externally replacable though. Typically they are pressed in and that is a head off job, are these different somehow?

dirtmonkey, just because you have low compression does not mean the rings are bad. The compression test is just one to determine if there is a problem, it doesn't really tell you what the problem is. You need a leakdown test to find out if it is rings or valves. Having good compression and smoke at start up would suggest valve guide seals though.

I also doubt the rings are bad at 160k, they should be good for double that.

Personally, I would probably sell or trade off the truck. There are lots of nice ones cheap and this job looks like a huge PIA to me. Good Luck

 

I've been looking at going to a diesel, but want to nurse this one along until after the Xmas bills are paid . Maybe guides was the wrong term? seats may be the correct term? On my Ranger there were two metal seats that fit around the stem and the seal fitted over the top. May be different on the Expedition. Learning as I go on this one...

 

The valve stem runs in the guide, the guide is pressed into the head. The valve stem seal fits over the valve stem and guide, bigger hole on the guide end, it is just a rubber boot really to keep excessive oil from passing through the guide into the combustion chamber.

The spring is attached to the valve with tapered on the outside, grooved on the inside, "keepers". The grooves match up with grooves in the top of the valve stem, the taper on the outside is an interference fit with the round disc on top of the valve spring (the correct term alludes me) The spring pressure holds it all together. That is a pretty standard set-up. I have never had the covers off one of these so I can only guess at the rest of the valvetrain configuration. Probably a cam down the middle with finger followers actuating the valves, and some sort of adjustment be it screw adjusters or shims on top of the valve stem.

The valve seat is in the combustion chamber, it is where the head of the valve rests when it is closed.

It will all make sense once you get a look at it but, just getting to the point where you can work on it will be a challenge.

Plugs will have to come out so you might as well replace those. You will need pressurized air to hold the valves closed while you remove the spring. None of it is brain surgery but if a valve drops, the head has to come off.

It might just be easier to pull the heads and have them redone. That way you can do headgaskets and intake gaskets, both known failure points. Now you are spending a couple grand though, hence my solution of dump it and RUN!

 

keepers! that's what I was trying to explain, brain damaged lol. 170K and the head gaskets are still strong, I don't see any reason to go that far. If I can't do the seals and adjusters without taking the heads off then Ill sell it for parts or a project. I can get a reman pair of heads for $600 but then start adding all the gaskets etc and it gets up near 1K and hell of a lot work. I'm a decent wrench and don't mind getting my hands dirty but I have too many projects already and not enough time.

I'm just looking for a quick fix to get me through the Holidays...