This might be a long one, but hang in there, I need your help.

My Y-block was running just fine. when I bought it. I promptly tore into the truck for a restoration. The oil drained was black and the antifreeze looked like it should.

After opening up the engine for a timing chain and intake replacement, I buttoned it up and got it running. Pulled the dipstick and noticed the oil was white-ish. Figuring that I made an assembly error, I took it back apart and made sure all the seals were sealed correctly (a litte extra silicone in all of the suspect areas) and I again used thread sealant on all the appropriate threads.

Once assembled, I again have water in the oil. It runs great, idles just fine, but the oil still has a little white tint to it. Keep in mind I just put it back together so tomorrow, it might be worse.

When it was idling, I looked in the radiator for bubbles, thinking it could be a head gasket. No bubbles. I'm fearing a cracked block but I don't know how this could happen between the time I bought it, tore it down and reassembled it. Remember, the oil originally drained was black - no hint of water. The bolts used on the timing cover weren't too long, I didn't notice any resistence and they were torqued to the appropriate ft/lbs. There are no external leaks.

Is there anything obvious I am overlooking before I tear it down again to replace the head gaskets? Is there a bolt that plugs the coolant passage that intersects the oil passage that I could've missed (the two in the back on each side of the head?)

Is there any test I can do to narrow it down? Should I just say screw it and run it and see what happens? I'm getting frustrated. It was fine before tear down - now it's not. I just can't see blowing a head gasket (though I did have a wicked backfire when starting it up) or a cracked block.

Any help would be appreciated.

 

Not sure how long you had it down. Could be nothing more than a little condensation. I'd change the oil and see if it cleans up a bit. Are you losing any water?? That's what would get me more concerned.

 

If your engine is stock, it doesn't have PCV, and depends on the draft tube to clear condensation out of the crankcase. If you are just sitting in the garage idling in cold weather, it will build up condensation until it is completely warmed up, then it will start to vaporize, but will re-condense if not drawn out by draft. Have you driven it on the road and gotten it really warm?

 

Ross has a good point. It may well clear up by just driving it a bit. Again, look for lost water.

 

What if you have oil in your antifreeze?

 

If you are sure it is coolant getting into the oil and not condensation, before tearing it back down to inspect, try dropping the oil pan and pressuring the radiator with a tester and look for where the coolant is comming from. This will give you an idea of where to look instead of trying to find the proverbial "needle in a haystack". Hopefully it is just condensation and not something serious.

 

If you are getting oil into the coolant, it depends on what engine you are running as to how serious this can be. If it is an overhead valve engine, it could be a head gasket or a crack in the block or head. Usually, a crack will allow water and oil to go both ways, while a gasket will sometimes only let it go one way.

 

I agree, it sure sounds like condensation.

I would start with a pressure test of the cooling system to see if you are losing pressure and then go from there.

Bobby

 

The condensation is a plausible explanation. I haven't ran it more than a few minutes at a time and I cannot drive it down the road. Today, I'm planning on firing it up (after I clear away the 12" of snow we got last night!) and allowing it to reach operating temperture. It was also suggested to me that areation of the oil could be a possibility. In either case, I think allowing it to run may clear up some of my confusion.

If that doesn't help me out, maybe I'll try dropping the pan and pressurizing the system. That's a good idea.

Thanks to all for your help. I'll update later.

Todd

 

Before I pulled the pan I would jsut pressurise the system and see what happens. If its not losing pressure then theres no call to drop the pan (what can I say?...I'm lazy)

Bobby

 

All of the respondents above know more about Y-blocks than I do. However, when I first read your problem, I was thinking water pump gasket. There may be some obscure bolt or plug missing, or the gasket might be wrong or in backwards.

I could be completely off track here.

 

Ok - Here's an update and it doesn't look good.

I fired it up today and allowed it to reach operating temperature. Out of the driver's side exhaust (I have open headers on it right now) white-ish smoke was billowing out. Out of the passenger's side, nothing. Closer inspection revealed oil spatterings on the concrete under the driver's side exhaust. When I finally shut it down after about 20 minutes, a trickle of oil (mixed possibly with water) came out. I looked at the dipstick and it was hard to tell. It didn't settle enough but it didn't look as white as before.

Could I be looking at a blown head gasket here? Would the symptoms be the same if my block was cracked?

Now that I think about it, it did smoke quite a bit on startup - the previous owner said he replaced the valve seals on one side but not the other. However, when I opened it up, the seals looked new on both sides. Now it makes sense (the jackass was covering it up).

Looks like I have no choice but to open it up again. Any thoughts? (aside from I'm a sucker).
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Welcome to fun with Y blocks .... I had a similar experience with my F600 when I first got it. I found that with a compression test, and then a "Cylinder Leakage" test, I was able to locate the offending cylinders ... #6 & #7 .... the head gasket had failed between those two. I initially thought that just replacing the head gaskets would do the deal. Wrong!! As I tore down the motor I discovered that two head bolts had been installed wrong. The Y Block motor has two end head bolts that are different length, and if one is put in an inner hole, it will bottom out and not torque correctly. Too little torque equals a failed head gasket. Fortunately mine had no other damage ... such as a block crack which I've been told can happen in this situation. Food for thought ...... The engine in my F600 had less than 500 miles on it after a full rebuild .... but obviously the mechanic wasn't aware of the head bolt differences.

Bob in Spokane

 

I wouldn't doubt you could have a problem, but are you sure the spatterings were oil, and not carbon mixed with condensate? If one side is running real rich, it will tar up your driveway with a black stain, and drool out of the tailpipe. Worth checking the plugs to see if there is a sooty covering on the driver's side and not the other.

 

Here's the latest - I pressure tested the cooling system. It held pressure just fine and I didn't notice any coolant loss. The oil cleared up after idling for about 25 minutes.

However, the oil spattering out of the driver's side header?... I did a compression check and they were noticably down on the front three on the drivers side (last one was at spec - 150lbs). The lowest measurement was about 60lbs.

The passenger side was better but one was way down (like 90 lbs).

Sooo, is it safe to assume that this engine needs t rebuild? Is there any way it could still be a head gasket. I'm holding out hope. I don't want to shell out 2k for a rebuild.