Head gasket and intake manifold

[Heybuddy]

So I’m changing gaskets on my 4.3 mer cruiser and I can not for the life of me get the intake manifold and cylinder heads off the block. All bolts removed soaked with PB Blaster, no luck. Any tips or tricks from experience out there?

 

[Scott Danforth]

with the distributor removed, the intake bolts removed, and the valve covers removed....simply put a pry-bar between the bottom of the thermostat housing and the top of the water pump and gently pry. once its off, then use a dead blow to break the heads free. keep in mind there are two dowel pins, so an upward blow to the front of the heads is best.

 

[Scott Danforth]

what is the reason you are needing to change the gaskets. most of the time if you have water in the oil, its a crack in the block from lack of winterization, or the exhaust manifolds failed and allowed water in the cylinders.

 

[Heybuddy]

what is the reason you are needing to change the gaskets. most of the time if you have water in the oil, its a crack in the block from lack of winterization, or the exhaust manifolds failed and allowed water in the cylinders.

Scott, I’m changing/checking for a breach in the head gasket because I had water in 1 of my cylinders after an over heating issue on the water. Doesn’t seem to water in the oil when I pull the dip stick, but it only having water in 1 cylinder worries me because it should be in 2 of them if the seal has failed...

 

[Bondo]

Ayuh,..... Did you do a compression, 'n leak-down test on that cylinder,..??

 

[Scott Danforth]

if you have water in only one cylinder, 99.99% of the time its your exhaust manifold to elbow joint has failed.

however since you have the bolts already yanked..... you now have to do a complete tear down, clean up of all surfaces prior to bolting it back together.

 

[San_Diego_SeaRay]

if you have water in only one cylinder, 99.99% of the time its your exhaust manifold to elbow joint has failed.

however since you have the bolts already yanked..... you now have to do a complete tear down, clean up of all surfaces prior to bolting it back together.

Yep. I'm dealing with this now. My manifolds let water into the exhaust, causing a valve to seize. It's a 1998 7.4. I pulled both heads today and off to the machine shop they will go.

Regarding the OPs question, I had a *heck* of a time trying to pull my intake manifold off today. Probably not the recommended method, but I ended up taking a big flat head screwdriver and hammered it into the intake gasket right above the water pump, then pry it up slightly. Came right off. Absolutely no damage to the block or intake surfaces.

 

[Lou C]

Well...I had the same exact problem....that intake manifold did not want to come off...tried what Scott suggested above...still no dice....so what I did...was get 2 screwdrivers....and cushioned the tips...with Gorilla tape....and carefully pried in the silicone joint between the block and manifold...and it popped off...with no damage to either...but those old gaskets...were baked on...like Kryptonite! it took me FOREVER to clean up the sealing surfaces of the intake...if I had it to do again I'd just let the machine shop do it for me...
On the other hand...the heads came right off...no struggle there at all...even though mine was run in salt water when I had to do a top end overhaul...

And as far as water in cyls...well...I had HGs blown in the right spot to put water in #2...and just a mist of water in #1...the exhaust was not the culprit...that would have been an easy fix lol.....