What would keep a new head gasket from sealing?

Originally Posted by Hemispheres
This happened a couple years ago but it's always bothered me.

I pulled a head on my buick and found cracks between the valves so I replaced them. The head gasket didn't take on the front cylinder bank. I cleaned the bolt holes, used copper spray a gasket and took extra care to line up the dowel pins and gently place the heads on the gasket. Even torqued the head bolts to 37 lb ft plus 120 degrees.

After firing it up and test driving it I noticed a substantial loss in power. I pulled the front head and found a lot of coolant in cylinder number 5. The rear cylinder bank sealed right up without any issues.

What could of caused that to happen?


Several things but this is like examining a crime scene that has been bulldozed and a garden planted

First- are you 1005 certain it was a "gasket leak" as opposed to an undetected crack? ( never assume a reman is 100% or it could be in the block but only open under loading or heat)

I do tons of NDT and many cracks are like that on pressure systems- that's why we have to use UT or X ray because magna flux wont find them.

Could be surface finish, surface plane/flatness, improper torque

all kinds of stuff

What did you try in order to fix it and what was the result?
 
Originally Posted by Astro14
If you did everything right, it wouldn't be leaking.

Instead of arguing with Trav, who's done this a lot, and whose work doesn't leak, perhaps you should read what he posted.


Put differently: what would keep a new head gasket from sealing?

Here's a few things...off the top of my head...

Poor cleaning of sealing surfaces. Using sealants when none are recommended. Damage to the head. Damage to the block. Defective gasket. Re-using old bolts. Improper torque.

You've got at least one of those, and perhaps more. I wouldn't use abrasives to clean a block, or head, ever. Too much can go wrong.


Well the engines still running so I guess I lucked out.
 
Originally Posted by ABN_CBT_ENGR
Originally Posted by Hemispheres
This happened a couple years ago but it's always bothered me.

I pulled a head on my buick and found cracks between the valves so I replaced them. The head gasket didn't take on the front cylinder bank. I cleaned the bolt holes, used copper spray a gasket and took extra care to line up the dowel pins and gently place the heads on the gasket. Even torqued the head bolts to 37 lb ft plus 120 degrees.

After firing it up and test driving it I noticed a substantial loss in power. I pulled the front head and found a lot of coolant in cylinder number 5. The rear cylinder bank sealed right up without any issues.

What could of caused that to happen?


Several things but this is like examining a crime scene that has been bulldozed and a garden planted

First- are you 1005 certain it was a "gasket leak" as opposed to an undetected crack? ( never assume a reman is 100% or it could be in the block but only open under loading or heat)

I do tons of NDT and many cracks are like that on pressure systems- that's why we have to use UT or X ray because magna flux wont find them.

Could be surface finish, surface plane/flatness, improper torque

all kinds of stuff

What did you try in order to fix it and what was the result?


I got another gasket and used the roloc/3M combo again with a fresh set of head bolts and it took just fine.
 
Originally Posted by Hemispheres


I got another gasket and used the roloc/3M combo again with a fresh set of head bolts and it took just fine.


Thinking like Occam with a dose of cause and effect, I would say the original malfunction was either:

defective gasket or gasket alignment

Defective fastener(s)

Improper torque

Possible surface imperfection

Any combination of the above
 
Water in a cylinder of a 3800, was that even a head gasket problem or something with the intake?
 
Originally Posted by mk378
Water in a cylinder of a 3800, was that even a head gasket problem or something with the intake?


It was pure coolant so it was a head gasket.
 
Originally Posted by Hemispheres
Originally Posted by mk378
Water in a cylinder of a 3800, was that even a head gasket problem or something with the intake?
It was pure coolant so it was a head gasket.

Pure coolant?
 
First, I agree with Trav and Astro. Just did a head gasket swap and did not use anything but gasket scraper and "fingernail" testing to confirm no damage to the original RA.

However, the Ford Tech on youtube says Ford recommends to use the rotary "finger wheels". Starting at 2:04. I personally would like to see the recommendation from Ford on this myself.




Fel-Pro has good info on gasket types and what to use for their gaskets and sealing:



It seems there are a lot of opinions on this topic. I have used the Fel-Pro replacement gaskets with success so far, but every job is different and presents its own challenges.

Each gasket type has it's desired surface RA for best adhesion and if that is ignored, problems will likely surface later.

Anyway, congrats on getting it fixed and running!
 
Last edited:
First, I agree with Trav and Astro. Just did a head gasket swap and did not use anything but gasket scraper and "fingernail" testing to confirm no damage to the original RA.

However, the Ford Tech on youtube says Ford recommends to use the rotary "finger wheels". Starting at 2:04. I personally would like to see the recommendation from Ford on this myself.




Fel-Pro has good info on gasket types and what to use for their gaskets and sealing:



It seems there are a lot of opinions on this topic. I have used the Fel-Pro replacement gaskets with success so far, but every job is different and presents its own challenges.

Each gasket type has it's desired surface RA for best adhesion and if that is ignored, problems will likely surface later.

Anyway, congrats on getting it fixed and running!

Guestion is, do those rotary fingers have abrasive like 3m pads or 3m roloc discs? Those abrasives get into the engine and are too fine to be filtered out.
 
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