Engine rebuild fail!

[discowolf]

My 4.0 was leaking coolant behind the engine somewhere after slightly overheating so I decided to rebuild it. I did the cam up and all new gaskets, water pump, hoses etc. I put it all back together and filled the fluids, was about to fire it up when I noticed coolant leaking from the driver side lower rear head bolt between head and block. The heads were machined, I cleaned the block well and looked for cracks. The only gasket o didn't put sealer on was the head gaskets cause the machinist said slap it in dry.
This project cost me almost $4000!!! Should I junk it and buy a jeep?

 

[discowolf]

Just kidding about the jeep, I already have a belly button and don't need something everyone already has!

 

[discostew]

Did you blow all the coolant out of the bolt holes? And the other question would be about your torque procedure. 90 degrees and then another 90 degrees after the original torque setting right? That makes a ton of torque. He was right about installing the headgaskets dry, nothing added to them. Make sure the coolant isnt traveling down from your intake gasket because it can ride that seam and look like its coming from the head. Put a pressure tester on it and see if you get a better idea of what could be leaking. Did you pay close attention when placing the head gasket on the head. TOP doesn't mean towards oil pan.

 

[Tugela]

Don't give up! I've only replaced head gaskets once, so bear that in mind when considering this. The overwhelming advice I received at the time was to install the head gaskets dry. Provided that

• the block is clean,
• heads are machined,
• new head bolts used, and
• tightening sequence/torque values followed precisely,

no additional materials are needed to create a durable seal. Having taken these steps, my head gasket job is holding strong 45,000 miles later.

One possibility is that you installed the gaskets incorrectly. They have to be oriented in a specific way. If that's the case, then a fresh set of gaskets and head bolts would solve it, all of which are available from Will Tillery - good quality and inexpensive.

You're in too far to walk away now. Take break from the project, think it through, other people here will offer suggestions, and you'll figure it out.

One point that could use some clarification: was the head bolt leaking coolant before you turned the engine on? I.e. it was leaking before the cooling system pressurized?

 

[discowolf]

Thank you guys for dealing with my dumb ass and helping! I am going to stick with it. I put the gaskets on the correct way, used new bolts, got the heads machined. I did have some confusion with the torque procedure. I torqued to spec and went a bit further. I didn't do it 90-90. I'm sure that's where I fucked up. It leaked before any pressure was in the system. It's been sitting for a week now and has lost a lot of coolant.
I'm not going to lie, My wife decided to move (she's the bread winner) while I had the truck in a billion pieces so I had to throw it all together really late one night. I'm going to do a sketchy midnight tow and part it till I get settled in.
I'm going to pull that head and inspect it again and re-torque the other. Will I need to purchase new head gaskets and bolts again?

 

[Maximumwarp]

If you only torqued to spec (15 ft lbs) then you had a long way to go before they were actually tight to the point they're supposed to be. I would guess that the bolts would be okay, having never been stretched, but I would pull the heads back off, clean and dry the mating surfaces, and re-install. Re-using the gaskets I'm not sure about. If they've been soaking in coolant for a while, I would probably replace them.

 

[discostew]

I would be tempted to just gain access to the headbolts and start the torque process again. It's up to you if you think coolant would damage the gasket material. Maybe someone else will chime in. If you dont take the heads back off to replace the gaskets make sure you at least take the plugs out and crank it over so all the coolant gets blown out of the cylinders. But if you didn't blow coolant from all the bolt holes you might want to do that. Good luck and hang in there, don't give up just yet. Live and learn.

 

[discowolf]

I just went and re-read the manuals I have and the torque is definitely part of the issue. One said 20nm then 180° +_ 5. Insomnia and a rainier said "just half ass it Tom and hope for the best" the other manual breaks it down better saying 20nm (15ftlb) then 90 then 90.
I'm usually a good mechanic but I think life and my brain got in the way. Every other step I took my time and I cleaned everything really well. You could eat off the block!
I'll have to order a new valley gasket so I'll get some new head gaskets too.
Thank you guys again for putting up with this!

 

[Tugela]

Insomnia and a rainier said "just half ass it Tom and hope for the best"

Sounds like the source of the problem has been located! When you get around to having another go with your new parts, here are some tips that helped me get it right the first time:

1. Follow the directions in the RAVE manual. This is available for free, I forget the link to it, searching here will get you to the right place. This is a searchable PDF so you can navigate all 866 pages easily. Find the head bolt tightening sequence instructions and follow those exactly. I made a hand-sketched drawing of the head bolt positions with numbered sequences and stuck it in the engine compartment for reference while I was doing it. Having the cheat sheet was very convenient.
2. Clean out the head bolt holes before inserting bolts. Buy a can of compressed air (like for cleaning dust out of your computer keyboard, the kind that comes with a little red plastic pipe for precise aiming). Cover the valves with a rag and then blast out each head bolt hole with compressed air.
3. To help with the 90, then 90 sequence I bought a paint marker and drew a line from the center to the edge on the head of each bolt AFTER tightening them to initial torque spec. This makes it easier to measure the 90 degrees. For example, if you draw your line from the center of each bolt to 12 o' clock position, then you know to tighten each bolt in sequence to 3 o' clock. Then go around in sequence again to 6 o' clock.

Getting it right takes some physical effort. I ended up using an extension on my breaker bar to achieve the correct torque on the head bolts.

bonus: apply sufficient RTV (or whatever sealant you use) to the ends of the clamps that hold the fore and aft edges of the valley gasket to the block. Going too light on this could result in coolant leaks, which is a bummer after you have everything back together.

 

[Maximumwarp]

3. To help with the 90, then 90 sequence I bought a paint marker and drew a line from the center to the edge on the head of each bolt AFTER tightening them to initial torque spec. This makes it easier to measure the 90 degrees. For example, if you draw your line from the center of each bolt to 12 o' clock position, then you know to tighten each bolt in sequence to 3 o' clock. Then go around in sequence again to 6 o' clock.

This. Exactly how I do 'em, works like a charm. Especially if you get distracted, have to reset the socket, drink your beer, etc.

 

[discostew]

I do something kind of like that. I have a yellow and a white tire crayon. First 90 gets one color then after the second 90 it gets the other. I find that you need to do something to remember what bolts have been torqued because I can't get thru one side without getting asked at least 2 questions by at least 2 people.

 

[discostew]

Sounds like the source of the problem has been located! When you get around to having another go with your new parts, here are some tips that helped me get it right the first time:

1. Follow the directions in the RAVE manual. This is available for free, I forget the link to it, searching here will get you to the right place. This is a searchable PDF so you can navigate all 866 pages easily. Find the head bolt tightening sequence instructions and follow those exactly. I made a hand-sketched drawing of the head bolt positions with numbered sequences and stuck it in the engine compartment for reference while I was doing it. Having the cheat sheet was very convenient.
2. Clean out the head bolt holes before inserting bolts. Buy a can of compressed air (like for cleaning dust out of your computer keyboard, the kind that comes with a little red plastic pipe for precise aiming). Cover the valves with a rag and then blast out each head bolt hole with compressed air.
3. To help with the 90, then 90 sequence I bought a paint marker and drew a line from the center to the edge on the head of each bolt AFTER tightening them to initial torque spec. This makes it easier to measure the 90 degrees. For example, if you draw your line from the center of each bolt to 12 o' clock position, then you know to tighten each bolt in sequence to 3 o' clock. Then go around in sequence again to 6 o' clock.

Getting it right takes some physical effort. I ended up using an extension on my breaker bar to achieve the correct torque on the head bolts.

bonus: apply sufficient RTV (or whatever sealant you use) to the ends of the clamps that hold the fore and aft edges of the valley gasket to the block. Going too light on this could result in coolant leaks, which is a bummer after you have everything back together.

More is not better big guy. The extra rtv will end up in lifters and cause them to not bleed. Or in the cooling system blocking off stuff like the bleed hose that goes back to the reservoir. I grind the ends of the endclamps so they don't interfere with the manifold settling into place. They used to tell us to do that in training but I never saw it in print. I also just leave those end clamps finger tight so they can move around a little while I get the intake torqued down. The first torque spec of the intake is so close to the torque spec of those that I just hit them after my first pass on all the intake bolts. Then after letting the intake sit there for at least 10 min. I hit all the intake bolts and take them to the 46lb ft or whatever the spec is.

 

[singingcamel]

Right or wrong here's what I do when tightening head bolts.
Follow the sequence and torque to 15 lbs. mark the head bolts with a metal marker and then torque 90 degrees from that mark following the correct sequence, and then another 90 degrees . you'll need a breaker bar for the last 90 degree sequence..

 

[p m]

I have to admit to smearing a thin film of sealant around the rear coolant passage holes in the head gaskets every time I am at it.

 

[discowolf]

Does anyone know the final torque value? I'd like to check it when I'm done. What is X? 15ftlb+90°+90°=Xftlbs. Or am I over thinking it?

 

[discowolf]

I have to admit to smearing a thin film of sealant around the rear coolant passage holes in the head gaskets every time I am at it.

I almost did that when I was in there. It seemed to make sense, but the machinist said raw dog it. I decided to take his advice because he had some really crazy race engine builds going on and my garage just has 1000 bicycles and antique single cylinder air cooled builds.

 

[helievacpilot]

Does anyone know the final torque value? I'd like to check it when I'm done. What is X? 15ftlb+90°+90°=Xftlbs. Or am I over thinking it?

Your over-thinking it. Just use the paint mark method and your good-to-go.

 

[discowolf]

Thank you! I'm a bit fried and just want to get it 100% perfect before I actually start it up!

 

[jymmiejamz]

Thank you! I'm a bit fried and just want to get it 100% perfect before I actually start it up!

It doesn't need to be perfect. Just do the 15 ft-lbs and the 90+90. There is no need to check it once you are done. Oil the threads and make sure the bolt holes are clean. There is no need to put sealant on the gasket.

 

[helievacpilot]

Yea, I was always a little scared of the angle-to-torque method. Did it on a 5.0 H.O. and was sure I was going to snap 'em off.
ALTHOUGH, it saves you from having to buy a big-ass torque wrench.