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I've never performed a leak down test before but looking at the set-up (make sure you're at TDC, intake/exhaust valves closed), if you were to have bubbles appear in your rad, it will be a head gasket (sound might help to determine which head gasket). You won't know if it's a head gasket AND lower intake gasket because if the head gasket is good, the air would not escape from the combustion chamber. If I said something in error, someone please chime in!
 

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Ideally a leak down test is to check your valves and rings to make sure they're sealing when the engine's all together but in this case I'm pretty sure he could do a leak down test as is and see if there's any air coming out each cylinder around the head gasket.
 

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Discussion Starter · #43 ·
Ideally a leak down test is to check your valves and rings to make sure they're sealing when the engine's all together but in this case I'm pretty sure he could do a leak down test as is and see if there's any air coming out each cylinder around the head gasket.
As is without the intake installed? Thanks
 

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Stick a mirror with a flash light down in the lifter valley to look up along the bottom side of each of the heads to see if the head gaskets are distorted or sticking out into the lifter valley indicating a blown head gasket.
 

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Discussion Starter · #46 ·
Stick a mirror with a flash light down in the lifter valley to look up along the bottom side of each of the heads to see if the head gaskets are distorted or sticking out into the lifter valley indicating a blown head gasket.
Tried this and didn’t notice anything. Local part store doesn’t have anything for rent so I’m waiting for one to be delivered. Thanks
 

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Looking forward to the leak down results. If the head gasket failed, I guess the coolant could seep out into the lifter valley or would it be more likely to seep into the oil from within the head? Due to oil pressure being higher than coolant, not sure coolant could seep into the oil from the head.
 

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Any time I’ve had lower intake gasket leaks I’ve been able to “see” a problem upon disassembly. I can’t tell from these photos due to the light or resolution if there were any small tell tale signs or not.

The damage that happens to bearings over time with antifreeze in the oil is REAL, so don’t mess around here with “most likely I fixed it”. That was my error 20 years ago and it but me in the azz big time and ultimately cost me an engine.

Gaskets are comparatively cheap. Take it all apart and do it right if your not sure. Be SURE that your sure is my two cents.
 
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Discussion Starter · #52 ·
Any time I’ve had lower intake gasket leaks I’ve been able to “see” a problem upon disassembly. I can’t tell from these photos due to the light or resolution if there were any small tell tale signs or not.

The damage that happens to bearings over time with antifreeze in the oil is REAL, so don’t mess around here with “most likely I fixed it”. That was my error 20 years ago and it but me in the azz big time and ultimately cost me an engine.

Gaskets are comparatively cheap. Take it all apart and do it right if your not sure. Be SURE that your sure is my two cents.
Agreed no more rushing it, going to wait on the leak down tester and go from there. I’m just trying to research what I should be listening to or looking for when doing the test and how it correlates to the root cause.
 

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Agreed no more rushing it, going to wait on the leak down tester and go from there. I’m just trying to research what I should be listening to or looking for when doing the test and how it correlates to the root cause.
Have a look on youtube for "Eric the car guy" and "leak down test". He has a good video explaining what to look for and what are the causes. I think he did the leakdown on a 5.3 V8 GM motor but it's still relevant info.
 
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Got the leak down tester and it’s damaged.
Damn! In your case you probably don’t care what the % of air loss you have but you want to simply pump the cylinders with air and see/listen as to what is going on. Can you use the line at least to connect to an air line and the other end into the cylinder bypassing the gauges? I’m assuming the gauges are the ones damages. The more prudent thing to do would be just to send it back and get another.
 

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Discussion Starter · #57 ·
Damn! In your case you probably don’t care what the % of air loss you have but you want to simply pump the cylinders with air and see/listen as to what is going on. Can you use the line at least to connect to an air line and the other end into the cylinder bypassing the gauges? I’m assuming the gauges are the ones damages. The more prudent thing to do would be just to send it back and get another.
I know it’s too bad that the gauges don’t work on the leak down tester but I’m thinking along the same lines as you are. Regardless of the gauges working or not I can run air through the cylinders to listen/see.
 

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Discussion Starter · #58 ·
I know it’s too bad that the gauges don’t work on the leak down tester but I’m thinking along the same lines as you are. Regardless of the gauges working or not I can run air through the cylinders to listen/see.
I’m just trying to think about this, what would be the results without having everything buttoned up. Where should the air that’s being pumped into the cylinder exit?
 

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I’m just trying to think about this, what would be the results without having everything buttoned up. Where should the air that’s being pumped into the cylinder exit?
With a motor in good condition, air should ONLY get past the rings in a small percentage. You will hear that as leakage into the crankcase, and since you have your lower intake off, you will hear it coming into the valley from the crankcase.

If its leaking compression thru a head gasket bad enough, you will see air or bubbles seeping from somewhere between the block and the head around that cylinder. If its intercepting a coolant jacket you may even see coolant bubble out.

Since you have the lower off, it makes it even easier to inspect both the intake and outer block side while you do this. Make sure the piston is at TDC so the valves are closed and so the pressure doesnt rotate the motor easily. If you hear leakage out the intake or exhaust valves your probably not on the right stroke. If youre certain both valves are closed and you still hear leaking thru the valves you discovered a new issue lol.

I usually also put a breaker bar and socket on the crank or accessory to prevent it from turning when pressurizing the cylinder.
 

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Forgot to mention, if compression is leaking into the coolant you may hear air bubbling in the coolant ports of the heads.
 
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