Water in crankcase

[steGTO]

Hello Guys,
i write from Italy and i am the proud owner of a 1968 GTO. Stock 400 cid, auto trans.
I have rebuilt by pros the engine 2 years ago . At that time i had water (cooling circut) into crankcase.
Last sunday i was driving my car and i noticed a lot of white smoke from exhaust and very hight temperature; another time water in oil.
Sameone tell me about cracked block or heads, but i think it is a remote possibility because the engine has only 60.000miles on it and i live in a warm place (never frozen water). It is also strange that for 2 years everything was ok. Anyway is it a thing i can see easily?
Next sunday i will start to work on my engine but before disassemble everything i'd like to have suggestions just to make things in the right way.
Thanks a lot and scuse my poor english.

[BoxWrench]

Your english is excellent, we're glad you stopped by.

First, are you absolutely sure that it's white smoke (might even smell sweet like anti-freeze) or maybe it's a blue looking smoke that would mean oil is buning.
If the "smoke" hangs around a bit and acts like steam from a kettle, it's water burning.

As you disassemble, start with the spark plugs to see if there is any sign of water or rust on the plugs. If you find some there, it could be a cracked block or head, but also could be a blown head gasket.
Then pull the intake and inspect the places where the intake gasket was supposed to seal the intake to the heads. It's possible to have a seal between a water port in the head or intake go bad and let water into one of the intake ports of the head.
On a Pontiac, you'll have a valley pan covering your lifter gallery. This is an extra barrier against water from the intake getting into the lifter gallery, it's common to see Chevy and Ford engines leak from intake to lifter gallery, but not in a Pontiac. However, pull the valley pan and check that seal as well.
Also on a Pontiac and many other makes, the bolts that hold the intake to the cylinder heads should have been sealed before they were installed. This keeps oil from creeping back up the bolt onto the intake and the opposite if an intake gasket starts leaking water. It is possible for water to seep through a gasket and then travel downt an intake bolt into the lifter gallery.

If you still haven't found anything, you could pull the water pump next, but it's more likely that on a Pontiac, the seal against the block face and the timing cover went bad. That would let water directly into the crankcase where the timing cover and oil pan meet in the front. You can leave the water pump bolted to the cover and pull the cover and pump together. Pull the bolts that go through the cover into the block and then the 4 bolts that go from underneath through the oil pan lip into the bottom of the timing cover.

If you still hadn't found a water leak, the next thing to do would be pulling the heads to check for a blown head gasket.

After that, you'd need to have block and heads checked for cracks. Don't forget the intake manifold internally too. Water passes through the front portion of any type of Pontiac intake.

Let us know what you find.

[steGTO]

Thank You very much. I will you know.

[steGTO]

So, yesterday i drive my car to my garage to disassemble the engine.
When the engine was hot i noticed that the hose from radiator to manifold was expanded ( i thought about the termostat didn't open; is possible not to use it?).
I put out the sparks: they were brown at the bottom (water) but when i turned the key to move the engine no water outside sparks holes.
So I started to remove the valve covers : internally they were covered by a lot of muddy oil and water! Then the manifold, and the gasket seemed a little out of order near the water hole.
Then i removed the pan cover, inside seemed all ok.
I removed the timing cover, i can not tell exactly the condition of gasket there because this is very thin and when you dissassemble it breaks.
I could also see at the bottom of the chain the first part of the inside of the pan; there was muddy oil also in it.
Now i don't know if it is necessary to remove the heads...

[BoxWrench]

If you didn't find a clear water seepage point where a gasket was letting water into the oil, there is always a possibility that an internal engine plug could have popped out or corroded through. There's a chance that a crack or corrosion in the block or head castings could have occurred as well.

If there is no sign of gasket failure, it would be a good idea to completely disassemble the engine and have the parts checked for cracks or corrosion at a machine shop. They can magnaflux the parts to determine if there are any fractures or other problems.

[steGTO]

I have just finished the GTO. Thanks Guys for the support.
Now i'll assemble the 350 sm for my chopped 47 coupe.
I have vortec heads on it and i have bought the new manifold gaskets with the orange rubber. It seem it does not need a sealer.
I have to use it or not?
Thanks

[BoxWrench]

You shouldn't need sealant on the intake ports, but just for good measure, put some around both sides of the gasket where the water ports are.

Use RTV silcone, but only a little bit. Spread it very thin.

[97AUTO]

Hi. I just read your post. If you have a blown head gasket, you will usually find one or sometimes two spark plug that are very clean. Also on the cylinder where the leak is the piston will be very clean on top with litlle or no carbon bulid up. It will appear noticeably different from the rest. You will quite often see this on two adjacent cylinders if you have a blown head gasket as the gaskets most often fail in the area between the combustiion rings on the chevy small blocks. I hope this is of some help in assisting your diagnosis. When I read white smoke from exhaust I immediately thought head gasket failure.