Stuck Cylinder Head
#1
Stuck Cylinder Head
Head Gasket(s) blown on my XK8 1997 4.0
I've got the timing chains and cams off and the head bolts out, but the passenger-side head is sticking to the engine block.
I have tried using a rubber mallet
Also levering with a crow bar in safe places.
No good so far.
Tomorrow, I will attempt to remove the other head so that I better understand the internal studs and guides.
However I would like to jump to my next plan in the hope of getting feedback from anyone who has done this sort of thing:
I have heard that I could block up the "valley" and lever against the inlet ports.
However I like the idea of pressure from the inside, after all that's what the engine was built to cope with
So.....
Because the cams are off, the valves are all closed.
I am thinking that I can then do the "rope trick"
i.e. insert rope through spark plug recess and fill the open cylinder(s)
then hand crank the crank via the pulley bolt
This should force the piston upwards against the head and the rope should ensure some pressure internally against the head.
I will take the other head off to make sure that my assumption that the valves are closed is correct.
Has anyone done this, or know anything that I'm missing?
I've got the timing chains and cams off and the head bolts out, but the passenger-side head is sticking to the engine block.
I have tried using a rubber mallet
Also levering with a crow bar in safe places.
No good so far.
Tomorrow, I will attempt to remove the other head so that I better understand the internal studs and guides.
However I would like to jump to my next plan in the hope of getting feedback from anyone who has done this sort of thing:
I have heard that I could block up the "valley" and lever against the inlet ports.
However I like the idea of pressure from the inside, after all that's what the engine was built to cope with
So.....
Because the cams are off, the valves are all closed.
I am thinking that I can then do the "rope trick"
i.e. insert rope through spark plug recess and fill the open cylinder(s)
then hand crank the crank via the pulley bolt
This should force the piston upwards against the head and the rope should ensure some pressure internally against the head.
I will take the other head off to make sure that my assumption that the valves are closed is correct.
Has anyone done this, or know anything that I'm missing?
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martinrichard (05-04-2017)
#3
#5
#8
Head Job!
Straight out there this morning and yes indeed the bolts were still there.
The head was off in under five minutes once I took them out.
Doh!!
Thank you both Bob Roy and JBzXJ40.
So, this is the first head off.
My impression is that the last head gasket replacement was done pretty poorly.
The surface of the block is scratched and the gasket is not multi layered steel.
(Bob Roy, I will use MLS when I replace.)
However I do not see any very obvious area where it is blown.
Having trouble attaching photos, will try again.
The head was off in under five minutes once I took them out.
Doh!!
Thank you both Bob Roy and JBzXJ40.
So, this is the first head off.
My impression is that the last head gasket replacement was done pretty poorly.
The surface of the block is scratched and the gasket is not multi layered steel.
(Bob Roy, I will use MLS when I replace.)
However I do not see any very obvious area where it is blown.
Having trouble attaching photos, will try again.
#12
Sudden and catastrophic overheating accompanied by total coolant loss.
This seemed to be blown out under pressure, perhaps from the coolant reservoir but definitely from the valley area.
The valley pipes seem okay, but I will be replacing them.
Like you, I wonder if I got the diagnosis wrong.
This seemed to be blown out under pressure, perhaps from the coolant reservoir but definitely from the valley area.
The valley pipes seem okay, but I will be replacing them.
Like you, I wonder if I got the diagnosis wrong.
#15
#16
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martinrichard (05-05-2017)
#20
In the future if you have all the bolts out and still have trouble removing a cylinder head, an old trick is to remove the timing chain so that all valves are closed then turn the engine using a socket on the crank until one of the two pistons in the middle of that bank is at its lowest point. If it is an engine (like on an MGB) where the two outer pistons go up and down together, then using the two outer cylinders feed several feet of nylon rope into the cylinder(s), then turn the crank again using the socket and a breaker bar on the crank nut so that the piston pushes the rope against the head. This is usually enough to pop the head free without damage. You don't ever want to pry on an aluminum head. This trick was used to remove the cylinder jugs from radial aircraft engines and I've used it several times with success.
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