DIY valve job?

[JJMaine]

I've got my cylinder heads off as many of you know and have found that each head has 1 leaking intake and 1 leaking exhaust valve.

I'm wondering if it would work for me to just get some valve grinding compound and lap them in so they seal. I also have stem seals that came with my head gasket kit to install. Should I re-lap all the valves or only the ones that are leaking? Never lapped any valves but figure maybe I'd use this as a good way to learn. Worse case, when I bring the heads to the machine shop to get resurfaced I can have them do it.

 

[Uncle Gump]

Honestly...

Since you're that far... you just need to have them reconditioned.

Lapping valves is performed after the valves and seats are ground. It really does nothing to reface valves or seats.

It's likely that they will still leak after lapping.

 

[JJMaine]

Ok thanks, I thought maybe lapping them would do the trick.

 

[JJMaine]

Will the hot tank or vapor blasting at the machine shop hurt the cam bearing surfaces (are those called journals?). I'm worried about paying a machine shop to do a bunch more work and then the heads come back with bearing surfaces like these reman heads.

As you can see from this video it happened to this guy and others from my limited research.

Is it possible to clean them here and ask them not to clean them before they do the work? Not sure how machine shops operate, I've spent about 10 minutes at one now.

 

[Uncle Gump]

If they don't media blast them it should be fine. You don't want that in your oil passages. I would think some hot tank methods could be harmful also.

Just tell the guy what you found out and ask him about his cleaning procedures.

 

[JJMaine]

So what are my chances of actually getting them to seal with a good valve lapping? 0%? 50%?

I ask because the two machine shops local to me say they'll do my heads but one said at least a month and the other said probably longer than that. I understand they aren't going to just bump me to the front of the line. But the one that resurfaced my reman trash head for me said he would skim my heads for me no problem in no time as it only takes him a few minutes..

If I can get them valves to seal then I'll be back in business. My only other option besides waiting for the machine shop (and I don't want to do it) is to buy some more reman heads from Autozone. I'd rather not as they are really expensive but the upside would be that if they show up trashed like the last set I got off eBay the. I can walk them right into AutoZone for a refund or replacement. And they come with a 1 year warranty.

Has anyone had a valve leaking and lapping it fixed it? My thought is what do I have to lose other then a few bucks on the necessary tools? If it doesn't work out I can always buy Autozone heads or go to the machine shop. On the other hand if there's no chance it'll work then I won't waste my time.

Regardless my cylinder heads are going to a machine shop whether I use them on this engine or not. I'm not going through this again haha

Any advice is welcome!!!

 

[85_Ranger4x4]

Lapping doesn't really do a whole lot to a less than ideal valve, like Gump said it is how to halfway break in a new valve contact area to the seat.

In 2025 I don't know how many people will bother to grind valves.

A good headshop will know how to blast/clean your heads. OHC aluminum heads are not really new tech anymore.

Good shops have a waiting list, if you are in a hurry roll the dice and get remain heads.

 

[alwaysFlOoReD]

Like you said, lapping the valves can't hurt, and may help. I'd give it a shot just for the knowledge.

 

[JJMaine]

I'm just wondering why mine are leaking? From what I've read most people never have issues with their valves when they are doing a head gasket on a Ranger or Explorer. My truck ran perfectly (started a little rough due to the coolant leaking into the cylinders overnight). I wasn't expecting to have any problems with my valves. I wonder if there is debris on the valve seats? Maybe those valves were open while I was taking the engine out? Maybe worth taking one out and seeing how it looks.

 

[JJMaine]

You would think if the previous owner overheated it bad enough to hurt the valves it wouldn't have run perfectly for the first year and a half I've owned it?

 

[lil_Blue_Ford]

I’ve lapped valves a few times. Figure it can’t hurt. I’ve done it the kinda sketchy way of using a drill to spin the valves, chuck a piece of metal in the drill and use a short piece of rubber hose to spin the valves with. Use lots of oil on the valve and don’t spin it super fast, work it in and out. If you have a bunch of carbon and small pitting on the valve and seat, lapping it will clean all of that up. Doesn’t take much to get a poor seal.

 

[JJMaine]

You just use oil and no grinding compound? Worth giving it a shot.

 

[19Walt93]

If you're going to try lapping them, thoroughly clean the valves and seats with a wire wheel to get all the carbon off first. Then inspect the valve faces and seats, if the seats are pitted wait for the machine shop, if it's just the valve faces you might get away with lapping in new valves. Think about it though, it's a time consuming job- do you really want to chance having to do it over again?

 

[lil_Blue_Ford]

You just use oil and no grinding compound? Worth giving it a shot.

Oil on the valve stem. Grinding compound on the seal/seat areas. Be very careful not to get grinding compound on the valve stem/guide areas, that needs to be oil soaked