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Discussion Starter · #61 ·
Forgot to mention, if compression is leaking into the coolant you may hear air bubbling in the coolant ports of the heads.
Thank you so much for the details and information. It was really helpful in understanding what I should be expecting by running this test.

I quickly went out and tried this out on cylinders 1 to 3. I made sure that I got the cylinders on TDC on the compression stroke. When running the tests on these cylinders I heard the air hissing in the crankcase around the distributor. For cylinder 3, I noticed it coming from the dipstick. Once I get more time I will redo the tests.
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Discussion Starter · #62 ·
Update, waiting to get the intake gaskets. Completed the leak down test on all of the cylinders, and noticed the following:

  • noticing hissing from the crankcase/dipstick on all the cylinders.
  • no bubbling noticed from the coolant ports or rad.
  • no coolant leaking out of the drain plugs during the tests.

I’m going to try out redoing the intake gaskets and hope that’s it. Any other suggestions?
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It sounds like head gaskets are ok. Did you see anything seeping between the head and block? Leak % seems ok?

How confident are you in the timing cover/ water pump gasket job? Thats another place where coolant can get into the oil.

If all the gaskets are sealed, then another possibility be a cracked block...lets hope its not that bad.
 
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Discussion Starter · #64 ·
It sounds like head gaskets are ok. Did you see anything seeping between the head and block? Leak % seems ok?

How confident are you in the timing cover/ water pump gasket job? Thats another place where coolant can get into the oil.

If all the gaskets are sealed, then another possibility be a cracked block...lets hope its not that bad.
Nope nothing at all, I was wondering if there is anything I could do to amplify a leak. I know for tire leaks you could put some dish soap on it to a find a leak.

The leak down tester I had purchased came in defective. I ended up just pumping in air through a compression to listen and check for leaks. Prior to doing a leak down test, I had completed a compression test. 125~ across all cylinders

I was thinking about the timing chain cover but I think I did a decent job with the point of failure in the gasket being limited.

How would I be able to check for a cracked block?
 

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Good job on the investigative work!

Make sure the block, heads and intake mating faces are perfectly clean. Don't go crazy with the RTV on the water ports of the gasket (very thin on both sides). Use alignment studs to help center the lower intake. If you have a friend that can help lower it, extra set of hands makes it much easier (one grabs the thermostat housing, other grabs the top rear). Put the bolts in place until the heads touch the intake. Wait for 15-20 minutes and then give them each a 1/4 turn in the correct sequence (helps seat intake flat). After that using same sequence, 8ft-lbs, 15ft-lbs, 22 ft-lbs. After an hour, final torque in sequence. After 24 hours, final torque in sequence. Once you've had a couple of heat cycles on the engine, remove the upper and torque in sequence one final time.

Since you had quite a bit of coolant in the motor, make sure to perform a couple of oil/filter changes to make sure it's all out (any cheap oil/filter will do). Monitor your coolant level to make sure all is good. If you don't live too far from Nepean, I can pass you my mitivac pressure tester in case you want to pressurize before firing it up.
 
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Discussion Starter · #67 ·
Seems like it was your intake gasket(s).
Good job on the investigative work!

Make sure the block, heads and intake mating faces are perfectly clean. Don't go crazy with the RTV on the water ports of the gasket (very thin on both sides). Use alignment studs to help center the lower intake. If you have a friend that can help lower it, extra set of hands makes it much easier (one grabs the thermostat housing, other grabs the top rear). Put the bolts in place until the heads touch the intake. Wait for 15-20 minutes and then give them each a 1/4 turn in the correct sequence (helps seat intake flat). After that using same sequence, 8ft-lbs, 15ft-lbs, 22 ft-lbs. After an hour, final torque in sequence. After 24 hours, final torque in sequence. Once you've had a couple of heat cycles on the engine, remove the upper and torque in sequence one final time.

Since you had quite a bit of coolant in the motor, make sure to perform a couple of oil/filter changes to make sure it's all out (any cheap oil/filter will do). Monitor your coolant level to make sure all is good. If you don't live too far from Nepean, I can pass you my mitivac pressure tester in case you want to pressurize before firing it up.
Thank you, that was an awesome breakdown with some great information. I think one of the failing points the last time I did it was the overkill of RTV.
Thank you for offering the mitivac pressure tester, will keep you posted if I need to borrow it.
 

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That's the one I just used, it better be the right one! LOL
 
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Discussion Starter · #70 ·
Started to scrape off old gasket/rtv. There are some stubborn areas which are not coming off around the coolant ports, seems like build up that has hardened over time. I don’t want to start digging into the heads or Intake which could potentially lead to other issues. Any suggestions? Pics added to show what I mean.
Automotive tire Motor vehicle Bumper Automotive design Tread

Automotive tire Motor vehicle Vehicle Bumper Automotive exterior

Automotive tire Motor vehicle Automotive design Hood Automotive exterior
 

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Dura-Gold 6 Piece Abrasive Filament Nylon Wire Bristle Drill Wheel and Cup Brush Set - Coarse Sanding Scuffing, 1/4" Drill Shank - Remove Rust, Corrosion, Paint - Surface Prep Truck Bed Liner Coating https://a.co/d/0V3hIku

I love these for getting old gasket material off.
They can also be bought at harbor freight.
 

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On the heads, since they’re cast iron don’t worry about using a razor blade. I also use scotchbrite pads and acetone (cotton rag not shop towels as they leave fibres). Cover the lifter valley to catch any debris. For the lower, since it’s Al, very careful with a razor not to dig material out. Scotchbrite pads are safe. Acetone and cotton rags to wipe clean. Careful on the lower if you’re going to use a drill with abrasive pads. If they’re nylon pads you should be fine but I’ve always done them by hand and they will come clean, just takes a little more time.
 

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Discussion Starter · #75 ·
I can admit I definitely didn’t spend this much time during my first couple of attempts. I’m finally getting close to doing the gasket install.
 

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Cleanliness is key. Any debris left in place may result in a leak. It'll be worth it in the end!
 

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Discussion Starter · #77 ·
I’m finally there, should I smear gasket sealer directly on the gasket around the water ports? Or place it instead on the head and intake?
 

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Very light coat around the ports on the gasket (head and intake side) is plenty. No need to also coat the head and intake itself. Do you have your alignment studs made?
 

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Discussion Starter · #79 ·
Very light coat around the ports on the gasket (head and intake side) is plenty. No need to also coat the head and intake itself. Do you have your alignment studs made?
Thank you, yes alignment studs are available. Going to see if my wife can assist with lowering it with me.
 

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I’m finally there, should I smear gasket sealer directly on the gasket around the water ports? Or place it instead on the head and intake?
Yes, small amount of silicone on both sides of the gasket around the water ports.

If you have studs to align it, you really won’t need a helper. Just drop that baby on there
 
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