Cracked head?

mark D

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Most likely the head gasket. At least you can start there.

Pull a spark plug and blow air in look for bubbles in the coolant. If it is pushing coolant out the tail pipe like you say, it should push bubbles back into the coolant. May have to find top dead for each cylinder so valves are closed.

Use a rubber tube inside the spark plug hole to feel when the piston is at on top so the valves are close. Than blow air into the cylinder for each. When you find the cylinder you now figured out part of the problem at least you don't have to do both sides.
 

MatttheHatt

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Most likely the head gasket. At least you can start there.

Pull a spark plug and blow air in look for bubbles in the coolant. If it is pushing coolant out the tail pipe like you say, it should push bubbles back into the coolant. May have to find top dead for each cylinder so valves are closed.

Use a rubber tube inside the spark plug hole to feel when the piston is at on top so the valves are close. Than blow air into the cylinder for each. When you find the cylinder you now figured out part of the problem at least you don't have to do both sides.
It is the #6 cylinder that is steam cleaned so I HG failure shouldn't introduce water into the cylinder.

I am hoping in the next month I can find time to pull the head and at least pressure test it. (Not exactly sure the shop that decked the heads did that...)

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mark D

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(Cheap fix): Go to Harbor Freight if you have one near by and get a cylinder pressure gauge. Its a good idea to know your cylinder PSI anyway and the gauge is about $20 bucks. That way you can know what the other side is doing before you crack the top end open. Yes I have done only one side in a money pinch, but I knew the other side had good compression.

(Suggest if you have the time and money); Don't just pull the head and slam a new gasket back on. Pay the money to take "both heads" down to a machine shop and resurface and grind the valves. Check the top of the block with a straight edge, and get a new radiator. Most likely the reason you have a blown head gasket.

One of the biggest issues the Discoveries have with blown head gaskets are heat failure due to clogged radiators or failed fans. Do yourself a favor and at least check your radiator.
 

MatttheHatt

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(Cheap fix): Go to Harbor Freight if you have one near by and get a cylinder pressure gauge. Its a good idea to know your cylinder PSI anyway and the gauge is about $20 bucks. That way you can know what the other side is doing before you crack the top end open. Yes I have done only one side in a money pinch, but I knew the other side had good compression.

(Suggest if you have the time and money); Don't just pull the head and slam a new gasket back on. Pay the money to take "both heads" down to a machine shop and resurface and grind the valves. Check the top of the block with a straight edge, and get a new radiator. Most likely the reason you have a blown head gasket.

One of the biggest issues the Discoveries have with blown head gaskets are heat failure due to clogged radiators or failed fans. Do yourself a favor and at least check your radiator.
Sorry for the late reply, work kinda took over for a while...

I've had the head off, it had been decked and #6 is still getting liquid into it. I am hoping I have time to pull the head again innthe next month or so.

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