1996 OHV 4.0 Explorer Head/Head Gasket Replacement Question(s)

[travsbengals]

I just got the thing back together friday. I broke a bolt connecting the EGR tube to the EGR valve, which had delayed my progress.

I had a small exhaust leak, tightened up the exhaust manifold and it helped. I think I still hear a small exhaust leak, but its hard to hear over the infernal ticking. Mine is ticking on the drivers side. I think I'm gonna try some of that marvel mystery oil additive when I change my oil and see if it helps

http://www.autozone.com/autozone/ac...stery-oil/_/N-260b?itemIdentifier=238994_0_0_

I really hate to have to tear the truck apart again, and buy rocker arms, pushrods, lifters, and gaskets. I think you have to change the camshaft also if you change the lifters. Changing the rocker arms and pushrods wouldn't be that bad I guess, but changing the camshaft doesn't sound like fun. I guess when it cools down in the fall I might try to fix it, assuming it lasts through the summer.

I don't see any leaks yet, check engine light hasn't came on. So overall, not too bad I guess for my first attempt at changing a head gasket.

I'll let you know if the mystery oil additive helps any, or let me know if you try it before I do. Good luck boss

 

[Abbondanza]

I put Lucas oil additive in my oil but no change on the tapping noise...I had to tighten my exhaust manifold bolts also, but I still think I have a leak as well, I probably need to tighten where the manifold hit the y-pipe flange bolts again. I get lean codes on the passenger side bank.

I may do the rockers and pushrods, you can do them with just the valve covers off, obviously the lifters are under the heads, so that would be a last ditch effort IMO.

Let me know about the Mystery Oil works out for you.

 

[Texan01]

It's not a hard job, but actually fun. I've got it down where I can do it in 6 hours if I hustle.

I've done it 3 times on mine, before i wised up and had the heads professionally checked. They needed to be milled just a bit, but passed the crack test with flying colors.

According to the machine shop that was the first set of Ford 4.0 heads they had seen with eleventy-billion miles that didn't have cracks in it.

Put it all together, and knock on wood, nearly a year later it's not sprung a new leak in the heater core or radiator.

Mine runs like a new one after I did all that, gas mileage even went up some. The milling didn't increase the compression enough to even make a difference in HP, but it did take enough slack of out of the valve train to quiet down the worn rockers.

 

[Abbondanza]

.

 

[travsbengals]

After I had put some Lucas oil stabilizer in, then used a quart of Marvel Mystery Oil on my next oil change. The ticking has seemed to get less loud over time between the 2. Still some ticking though

Unfortunately I have a freakin oil leak. Seems like its coming from the back of the motor, above the transmission. Oil drips down off both sides of the tranny and the leak seems to be getting worse.

Anyone got any ideas of where the leak might be coming from? Hopefully the back sides of the valve covers? Isn't the oil pump right there? Could that be leaking? Do I have to take the heads back off if its the oil pump?

I'd like to get an idea of where the leak could be coming from before I start tearing this stupid thing apart again, I just can't see where its leaking from

 

[Dono]

My money's on the valve covers. I had the same issue and really struggled with fixing it.

It could be the lower intake gasket, or the original around the cam position sensor. I really doubt the cam sensor though.

It's not the oil pump, it's in the pan, so there's no way it can be that.

The valve cover gaskets cork? If so, change them to the rubber ones.
My issue was the drivers side where the valve cover bolts to the lower intake at the back. I'm not sure if the valve cover bolt didn't go in to the lower intake straight, or the bolt was too long. I ended up taking the bolt out and adding a few washers. Then I could at least feel when the washers were tight, holding the valve cover down. It's tough to see and feel what's happening back there.

 

[travsbengals]

Thanks Dono!

The valve cover gaskets I used were from the felpro kit, and if I remember correctly, they are cork. I do remember when putting the valve covers back on, it was a pain to tighten up the bolts on the backside so you're prolly right. I'll get some rubber gaskets and see what I can figure out next weekend. Hopefully its not the lower intake gasket

I appreciate it,

T

 

[Dono]

Im getting the parts together to install a new motor, and I ordered the premium gasket set from Rockauto, only to open up the box and see cork valve cover gaskets. Not very premium. I ordered the rubber valve cover gaskets, as Im not wasting my time and energy installing the cheap ass ones. The advantage I will have is the motor will be out of the truck so it will be really easy to see if something isn't right when installing.

If anyone wants some new cork ones, they can have them for the cost of shipping.

 

[Runnin'OnEmpty]

Good thread on cracked heads!

One question about the crack between the valves
on Abbondanza's head....would coolant actually
get into the cylinder from that crack?

Is there a particular area that cracks in these
heads?

 

[Dono]

Yes, coolant leaks thru the crack. I found if I stepped hard on the gas I'd have to replace the spark plug in the cylinder with the head crack. The coolant would hit the porcelin on the spark plug and crack it. Like clockwork. Became agrivating.

I think that crack between the valves is very common on factory heads.

 

[koda2000]

I have a ryobi finishing sander with the triangle head, was thinking of using that on the block surface and the water pump mating surface to clean them up.

How coarse can the grains be? Would 60 grit be too abrasive? Don't want to ruin the mating surface(s).

STOP! you don't want to using sand paper on these surfaces. you don't want to remove any metal, just the crud. if you start removing metal the sealing surfaces will be ruined.

 

[Runnin'OnEmpty]

Thanks for the replies. I suspect a problem with my
'new' Sport; it has the usual symptoms. (Start-up misfire,
small loss of coolant, dirty residue in the coolant along
with a strong gasoline odor.)

When replacing the upper intake gaskets, I noticed it
already had new ones along with a new fuel rail gasket,
so the previous owner has been chasing this problem.
(Probably why it was traded.)

Number 1 plug looks suspicous with a discolored insulator,
compared with the others. I'm trying to figure out if the
head's cracked, headgasket's failed, or maybe a leak in
the LIM gasket where it mates with the head...???

 

[Dono]

Impossible to know. All faults you listed are quite common.
What you are describing was cracked head for me.
Your gonna ng to have to tear in to it.

If you find your lower intake gasket ks blown, you still could have a cracked head.
Hate to be mister doom and gloom.

 

[keleko17]

Stupid question, would my 99 OHV be the same engine? I know there are a bunch of pictures with this thread, but I am not sure if I am capable of performing this repair. But I am pretty much at the point of using the truck for target practice, selling it for parts, or playing mechanic in my spare time.

Side note: I am sure mine is "wired" the same with the ignition coil, but I thought it went 1, 2, 3 (Front to back on the passenger side.) 4, 5, 6 (Front to back on the drivers side) I guess I never paid attention to the order of the coil pack, but I guess that has to do with the firing order.

 

[Dono]

Stupid question, would my 99 OHV be the same engine? I know there are a bunch of pictures with this thread, but I am not sure if I am capable of performing this repair. But I am pretty much at the point of using the truck for target practice, selling it for parts, or playing mechanic in my spare time.

Side note: I am sure mine is "wired" the same with the ignition coil, but I thought it went 1, 2, 3 (Front to back on the passenger side.) 4, 5, 6 (Front to back on the drivers side) I guess I never paid attention to the order of the coil pack, but I guess that has to do with the firing order.

Yup, same motor.
And, on the coil pack, you have the 1,2,3 right. The drivers side is not 4,5,6 though.

 

[Runnin'OnEmpty]

Impossible to know. All faults you listed are quite common.
What you are describing was cracked head for me.
Your gonna ng to have to tear in to it.

If you find your lower intake gasket ks blown, you still could have a cracked head.
Hate to be mister doom and gloom.

Doom and gloom, lol, I've been trying to talk myself
into thinking it's not a cracked head but have to face
reality sometime.

Since the #3 and #4 cylinders are prone to cracking, I
pulled the plugs again for a look, but they looked OK
to me. #1 is the only one that looks different with a
discolored insulator. There are no leaks on the outside
of the block, as would be seen if the intake gasket was
leaking at the coolant ports.

I've ordered a leak-down tester and a 13mm impact
socket (6 point) for the exhaust header connection.
Maybe a leak-down test will show something....

Are there any problems in reaching the headbolts
that are back near the firewall?

 

[Dono]

No issues with the head bolts with the motor in the vehicle.

Truthfully, once the lower intake is off, you have rocker arms, exhaust, and head bolts to pull off to yank the heads. Not much more, really.

But, you have the added costs of more gaskets, head bolts, and machine shop time. Maybe even a new head or two. I'd say do the whole thing if you have the cash.

The job is really straight forward. No timing, or anything like that to worry about. 60k isnt much mileage on that motor so bottom end should be great, but those heads are so prone to cracking its impossible to guess.

 

[Dono]

pumping some air pressure in to the weak cylinders and pulling the rad cap off will give you a pretty good hint on a head crack to a coolant port. Bubbles are a bad thing.

 

[Runnin'OnEmpty]

Thanks for the tips, Dono. I'll definitely look for
bubbles during the leak-down test. Hoping that
will give me an idea of the problem cylinder,
so I can closely inspect the head and headgasket.

I already have a gasket set and headbolts on hand,
and am thinking about installing both new heads.
Alabama Cylinder Heads has them for about $208
each. They're the 98tm heads.

 

[Dono]

I say buy the heads, do. A mild port and polish yourself, and pull the front of the motor apart while your at it and replace the cam with something that breathes better.

Where do you stop once you start? That's the million dollar question.