Head gasket replacement checklist

[Rocket Man]

Awesome job. Takes me back to when I did the.blower, cam, valve springs and roller rockers on The Beast. I'm amazed it ran well enough to drive with only half the cylinders firing! Good to see it running right .

 

[afpj]

Wow, I wish I had to ability to do a job like that. Congrats!
So not connecting one half of the coil packs....is that like AFM?

 

[Matahoe]

Wow, I wish I had to ability to do a job like that. Congrats!
So not connecting one half of the coil packs....is that like AFM?

Thank you. I actually come from a family of draftsman, mechanics and engineers so it was pretty basic for me. Just follow the manual and put stuff back in the same place it came from. Nothing to design or test...so pretty rudimentary.

One thing I was very sure to do was to make sure everything was as clean as possible. In fact you probably could have ate off the cylinder heads and block they were so clean. Valves were cleaned down to bare metal and hand lapped into the seats. Combustion chambers and piston heads...spotless. Clearances were checked with micrometers and calipers. Every step along the way what you would find in a Chiltons manual...followed.

Its not that I wanted to be uptight about all the work. I just didnt want anything failing out the gate. I also wanted to save as much money as possible given that the tasks were well within my skill range to complete myself.

Disconnecting one half of the coil packs is definitely NOT DOD/AFM. For one the right bank with cylinders 2 4 6 and 8 does not denote the firing order. So canceling them out creates a very rough running...unstable engine. I probably had about 25-40 horsepower available when I drove off on my first trip with 2 4 6 8 coils dead. Not to mention the engine is off balance so I assume there was a bit of damage done somewhere along the line to the crankshaft (however small). Oil pressure was good so I kept on.

 

[Matahoe]

Awesome job. Takes me back to when I did the.blower, cam, valve springs and roller rockers on The Beast. I'm amazed it ran well enough to drive with only half the cylinders firing! Good to see it running right .

Thanks. I know right! It barely ran at all. Gone are the days of the two injector TBI with one coil 5.7 liter engines. Troubleshooting them wasn't as complex.

 

[Matahoe]

Hmm. Well I hope this isn't a bad omen. it's been a few weeks since I finished the heads. At the end of every week I notice the reservoir is roughly 1-2 quarts low on antifreeze.

Any ideas? Im hoping it is just air. I don't smell any coolant burning or steam out the tailpipe.

 

[Rocket Man]

1-2 quarts every 6 weeks for how long now? I could see maybe the first week at the most but even then that seems like a lot.

 

[Larryjb]

Thanks to you all. This thread came at a good time for me. I have a non-Castech head that is cracked and leaking coolant into my oil. I plan to start work tomorrow. The machine shop has a replacement head ready for me. Sounds like I'll be doing lifters and perhaps valves as well.

 

[Larryjb]

Hmm. Well I hope this isn't a bad omen. it's been a few weeks since I finished the heads. At the end of every week I notice the reservoir is roughly 1-2 quarts low on antifreeze.

Any ideas? Im hoping it is just air. I don't smell any coolant burning or steam out the tailpipe.

'
Did you replace the suspect head? If not, pull the valve cover and pressurize the cooling system. If it's leaking at the suspect point, you will see water weeping through the crack. The fact that it was clean in that area suggests you had a cracked head. I'm sorry I didn't see this thread until now. That crack was just like mine.

 

[Matahoe]

'
Did you replace the suspect head? If not, pull the valve cover and pressurize the cooling system. If it's leaking at the suspect point, you will see water weeping through the crack. The fact that it was clean in that area suggests you had a cracked head. I'm sorry I didn't see this thread until now. That crack was just like mine.

It ended up not being a crack. One shop pressure tested it up to 150 psi and it never leaked. Another shop told me it really only needs to be tested at 15 psi (because thats the radiator cap limit). However my thinking is that the first shop tested it up to 150 because it wasnt torqued down or heated up.

I put the head back on with a new gasket. The reason a lot of these posts are here.

I am still keeping an eye on the coolant level. Didn't notice any large drop in the recovery tank after towing my RV 400 or so miles. Will more than likely send in another oil sample.

On a side note, I did notice that the exhaust was still leaking a small amount under heavy loads. I could smell some pre-cat exhaust while slowing down a few times. I did use MLS exhaust gaskets and if i remember correctly the manifold surface wasn't entirely flat...so that's probably the source of the leak. I'll try those thicker FelPro exhaust gaskets if I cant sand down the manifold evenly.

 

[Matahoe]

Just check again today. Coolant and oil levels still full after that trip.