Antifreeze and oil

[cwilkie]

I think I have a problem. I was pushing snow this week after th big North Dakota blizzard and I thought it would be a good idea to check the oil and antifreeze. Both are a little low. No biggie. I decided to add oil and antifreeze. Today I started the truck to go fill up on gas and I decided to pop the hood when I got back. On the intake by cylinder 1 there was a small pool of oily antifreeze. Near cylinder 5 & 7 there was a small pool of oil. Now my questions is does this mean I have a bad gasket or could the intake be cracked. The truck has a fresh 427bb where all the cast iron was checked for cracks by the machine shop before assembly and it did not leak for almost a year until now. I can change an intake without too much trouble but I do not have another cast iron intake lying around. Thanks guys.
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[geezer#99]

Did you use sealer on the intake bolts?

[TBONE1964]

The most likey cause of your oil on the intake is from oil seeping past the threads on the intake bolts. some of the intake bolts thread though an open hole right into the lifter galley and it is common for oil to work it's way through the threads of the bolt and into the valleys near the bolts.

The fix is to remove each bolt, clean and apply a small amount of high temp rtv onto the threads.

The antifreeze near #1 may be a t-stat gasket or upper radiator hose leak. If you can get your hands on a pressure tester, you can pump it up to 15 psi and see where the leak is coming from. Maybe just a loose hose clamp.

I don't think you need to worry about replacing the intake unless it is cracked somewhere and from what you stated, yours should be good.

[7dee2]

Originally Posted by TBONE1964

The most likey cause of your oil on the intake is from oil seeping past the threads on the intake bolts. some of the intake bolts thread though an open hole right into the lifter galley and it is common for oil to work it's way through the threads of the bolt and into the valleys near the bolts.

The fix is to remove each bolt, clean and apply a small amount of high temp rtv onto the threads.

The antifreeze near #1 may be a t-stat gasket or upper radiator hose leak. If you can get your hands on a pressure tester, you can pump it up to 15 psi and see where the leak is coming from. Maybe just a loose hose clamp.

I don't think you need to worry about replacing the intake unless it is cracked somewhere and from what you stated, yours should be good.

Some of these intake manifold bolts also go into the coolant passages so do what TBONE1964 suggests with the thread sealer but I would start in the middle and work your way outward then re-torque the intake manifold bolts (cast iron head) 25 - 30 ft.-lbs. in the correct sequence. If it still leaks water check that the thermostat housing is sealed as suggested. Should not be a biggie!

[cwilkie]

I do not recall if the engine builder used sealer. Do you know the torque setting for the intake? My book is packed away.
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[TBONE1964]

Intake bolts for a BBC are 30-35 lbs torque. I would start in the middle and go in a circle until you reach the ends.

[cwilkie]

Awesome. I just went out to check and the thermostat housing is leaking so that explains the antifreeze. It has an o-ring so I will take it off to clean it and put it back on. I will follow your instructions when I re torque the intake bolts.

I guess it looked worse at first site than it really is.

Where I live a plow or a bobcat is a must in the winter. Thanks for the great advice.
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[cwilkie]

Awesome. I just went out to check and the thermostat housing is leaking so that explains the antifreeze. It has an o-ring so I will take it off to clean it and put it back on. I will follow your instructions when I re torque the intake bolts.

I guess it looked worse at first site than it really is.

Where I live a plow or a bobcat is a must in the winter. Thanks for the great advice.
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[Sammy]

If your using a aftermarket intake that isn't cast iron make sure you check the torque from the manufacture's chart. Eldebrock aftermarket intake torque sequence and specs are much different than your stock cast iron.

[cwilkie]

I have a standard cast iron intake.
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[piecesparts]

Here is something to think about, You need to wipe down the intake and make sure it is clean, start the truck on a cold morning and watch the T/stat housing to see if it leaks when the metal in the intake and the housing are cold. There tends to be leakage around these connection points, due to the dissimilar metals in the two item and that is where your antifreeze is coming from.