Head gasket replacement
Three Wheeling
Joined: Jan 2010
Posts: 88
Likes: 1
I was lucky and had my heads surfaced and a valve job by a guy who'd done lots of them. he had to grind the valve stems a little to get the correct height.
the heads develop leaks at the water jackets at the ends. I'm sure this is due to the aluminum shrinking after it's been heat cycled. further, I believe the valves leak from the factory due to a poor valve job from new. this is probably why they have a tendency to stick....they get deposits on the stems from leaking
so the heads definitely need to be surfaced and IMO definitely get a valve job
my engine ran so much better it was surprising. it had noticeably more power when climbing mountain hills in overdrive
BTW the bolts at the back are hard to reach. try a 1/2 inch wobble extention....not a swivel....a wobble
replace the plug wires with something you won't have to mess with ever again
the heads develop leaks at the water jackets at the ends. I'm sure this is due to the aluminum shrinking after it's been heat cycled. further, I believe the valves leak from the factory due to a poor valve job from new. this is probably why they have a tendency to stick....they get deposits on the stems from leaking
so the heads definitely need to be surfaced and IMO definitely get a valve job
my engine ran so much better it was surprising. it had noticeably more power when climbing mountain hills in overdrive
BTW the bolts at the back are hard to reach. try a 1/2 inch wobble extention....not a swivel....a wobble
replace the plug wires with something you won't have to mess with ever again
Last edited by dougn; Dec 16, 2013 at 08:41 PM.
Rock Crawling
Joined: Jul 2012
Posts: 486
Likes: 1
From: Kaintuck ee
Also need a very long and heavy duty breaker bar to tighten the stretch bolts
Sounds like you are getting there
TReK
Joined: Mar 2012
Posts: 3,171
Likes: 45
Use a 5/8" black impact socket on the head bolts.
That is all that will hold up to the torque.
Also a dab of wheel bearing grease under the head bolt rim.
make sure the head bolt holes are clean. Blow them out with air.
light oil onto the head bolts and put a stripe of paint across the head bolt face and then
get a pipe. You can use a pipe from a floor jack.
I bought a gas iron pipe from Mc Guckin hardware in Boulder CO
That is all that will hold up to the torque.
Also a dab of wheel bearing grease under the head bolt rim.
make sure the head bolt holes are clean. Blow them out with air.
light oil onto the head bolts and put a stripe of paint across the head bolt face and then
get a pipe. You can use a pipe from a floor jack.
I bought a gas iron pipe from Mc Guckin hardware in Boulder CO
Thread Starter
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Camel Trophy
Joined: Nov 2012
Posts: 3,717
Likes: 248
From: Longview, Texas
All right I found a real machine shop that will plane the heads, and I am almost down to them. Another question...
Recall that the engine I am pulling the heads from overheated, definitely had a massive blown HG, and that my ex kept driving it until it completely stopped... There was no ticking and that engine ran fine to that day. However, it was very poorly stored.
I asked the shop about flanged liners in case I just do the bottom end. He knows what they are and can machine the lip for them in each cylinder. 150 bucks to bore and machine the lip on each cylinder. I'm not spending that. He suggested I not do that, too. He said the liners are probably fine but since there has been coolant M the engine, there might be problems with the cylinders. What does that mean? What should I look for? He also said that if there was any damage to the liners or pistons he would recommend boring them and replacing with larger liners and oversized pistons. Is that advisable? I seem to recall that the difference between the 4.0 and 4.6 is length of the stroke, not diameter of the cylinder. Anyway, before I haul everything to the shop I would appreciate any advice. Also, this engine overheated badly... Is there anything else I should visually look for?
Recall that the engine I am pulling the heads from overheated, definitely had a massive blown HG, and that my ex kept driving it until it completely stopped... There was no ticking and that engine ran fine to that day. However, it was very poorly stored.
I asked the shop about flanged liners in case I just do the bottom end. He knows what they are and can machine the lip for them in each cylinder. 150 bucks to bore and machine the lip on each cylinder. I'm not spending that. He suggested I not do that, too. He said the liners are probably fine but since there has been coolant M the engine, there might be problems with the cylinders. What does that mean? What should I look for? He also said that if there was any damage to the liners or pistons he would recommend boring them and replacing with larger liners and oversized pistons. Is that advisable? I seem to recall that the difference between the 4.0 and 4.6 is length of the stroke, not diameter of the cylinder. Anyway, before I haul everything to the shop I would appreciate any advice. Also, this engine overheated badly... Is there anything else I should visually look for?
Thread Starter
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Camel Trophy
Joined: Nov 2012
Posts: 3,717
Likes: 248
From: Longview, Texas
Sorry, that last was from my phone. Here is the driver side bank:
The rear set of valves looks bad and the final one looks unseated:
It is a mess:
Not sure about these lifters either:
Wife caught me in dress clothes before I could remove the passenger side heads, but I am expecting the same. The gunk on the front two cylinders, above, shows very clearly that there was a massive leak. So far I am not seeing any cracks. Anyone have any observations or suggestions? I started with the idea of just pulling the heads but I am wondering whether the bottom end is usable. The liners look pretty okay to my eyes, but I won't know until I pull it all apart.
I did nick the bottom surface of the valve cover with my socket dammit... the head bolts are incredibly tight.
The rear set of valves looks bad and the final one looks unseated:
It is a mess:
Not sure about these lifters either:
Wife caught me in dress clothes before I could remove the passenger side heads, but I am expecting the same. The gunk on the front two cylinders, above, shows very clearly that there was a massive leak. So far I am not seeing any cracks. Anyone have any observations or suggestions? I started with the idea of just pulling the heads but I am wondering whether the bottom end is usable. The liners look pretty okay to my eyes, but I won't know until I pull it all apart.
I did nick the bottom surface of the valve cover with my socket dammit... the head bolts are incredibly tight.
Last edited by Charlie_V; Dec 17, 2013 at 08:31 PM.
TReK
Joined: Mar 2012
Posts: 3,171
Likes: 45
Hi Charlie,
I think your valley gasket was leaking a bit too.
If you look closely at the head gaskets, look for a breach between the water jacket and the cylinder.
Unfortunately your engine has ingested a lot of antifreeze.
You may also need to replace the main bearing shells if the engine starts to knock at low speeds.
You can do that later.
You have enough to deal with on the top end.
Lots of cleaning needed.
As long as the engine did not ever overheat, your liners are probably fine.
I think your valley gasket was leaking a bit too.
If you look closely at the head gaskets, look for a breach between the water jacket and the cylinder.
Unfortunately your engine has ingested a lot of antifreeze.
You may also need to replace the main bearing shells if the engine starts to knock at low speeds.
You can do that later.
You have enough to deal with on the top end.
Lots of cleaning needed.
As long as the engine did not ever overheat, your liners are probably fine.
