Coolant in oil on a 430

Looking for some suggestions here. The 430 was rebuilt and has been running since July of 03. First oil change after break-in was fine and the last time I ran it the oil looked fine. Am fairly sure there wasn't coolant at the time. But not sure at this point.
Today before I fired it up I looked at the oil and it was cloudy. Sure enough, I drained a good amount of coolant from the pan. Removed the valve covers and there was some white sludge on the heads. No green.
Ran a pressure test on the radiator and at 15 psi, the water pump started to seep. Once it dropped to around 13-14 psi the leak stopped and the pressure did not go down. Nothing bubbled from the heads, so I don't think there is a crack there.
There is no oil in the coolant in the radiator and the motor ran smooth and fine with no misses or white smoke from the pipes. I don't think it is a cracked head or block nor a bad head gasket.
This is a standard rebuild with stock pistons, steel head gaskets (coated with coppercoat which I have done for years) and the metal intake which was sealed as usual with hi-tack and rtv around the water ports.
Obviously, I don't want to fire it up again but am looking for an idea of where the leak is coming from. My only other thought is a bad timing cover that is leaking from a crack or from a porous area.
I am sure it will have to come apart again, but am looking for a most likely starting point. I have been doing motors for years and this is the first one (0f course) that has ever leaked coolant into the oil.
Any ideas are greatly appreciated.

Thanks!

 

What about a leak at the intake manifold gasket? I just went thru the same thing. turned out to be incompatibility between 71 block and 73-74 heads ou:

 

Am going to go through a couple of things tomorrow. I know the heads/block/intake all match up. Don't think it can be a head gasket as there is no white smoke when running. If this motor has 3 hours of running time it is a lot. Of course anything is possible.
The only thing that is leaking is the water pump and then only at 15 psi. It will need to be replaced, obviously. The strange thing is that at 14 psi the pressure tester stays there with no drop. A head gasktet, intake gasket or crack in the block/heads should show a pressure drop. Fun Fun!
It is probably some bizarre thing like the pump leaking and the coolant is getting past the front seal or the oil pan gasket and then into the pan.
Thanks for the replies. I will keep what happens posted.

Mark

 

Did you modify water pump housing?

If you drilled a holes in water pump housing to install cam bumper as some enthusists do this may be a problem as well.

I did this to minimize camshaft oscillation and stablize timing. Even though I used JB weld to seal the threads and housing this is always a concern to me.

weekender

 

Here is the latest update. I spoke too soon when I said there wasn't a pressure drop. After draining another quart of coolant from the pan, I drained the radiator and then pressured it up with just air. Well, this made a big difference and it goes to "0" in about 5-10 minutes.
Removed the valve covers and did the old listen through a hose trick. Sounds like there is air escaping from the drivers side rear from either the head or intake gasket.
The plugs looked ok and were only wet from gas. Really don't want to spin the motor over to do a compression test just yet as the oil is very cloudy and I don't want to chance getting coolant sucked into the oil pump. As it is I am not too happy with the thought that it may have run the last time on contaminated oil. If I can fix the leak, the oil will be changed a couple of times to flush any coolant from the system. Hopefully the bearings will be ok.
At this point the next step is to pull the intake. Am considering going with composition gaskets when it gets put together again though I have never had a problem with the metal ones (always a first time). While the intake is off, the heads can be checked to see if the gaskets were leaking. Sure don't want to pull the heads on an a/c car. :ball:
Enough for today.

Thanks,
Mark

 

Finally got the heads off and this is a real winner. Pics are attached, but not too clear. May try to get some better ones.
The drivers head was leaking from the gasket area, but from a really strange reason. The drilled water passage in the cylinder head was not centered and drilled properly when the head were made. :shock: Have never seen this before on dozens of heads, but the center hole that is sealed by the gasket at the scallop in the block did not mate properly when using the steel head gaskets. The hole was just off enough that it began to leak after wearing away the sealer that was used.
It looks like composition gaskets might solve the problem as long as there is still enough casting on the scallop to seal off the off-center hole. Here is a pic.
Mark

 

It is a shot of the cylinder head and the head gasket which clearly shows that the coolant hole did not seal over the bead in the steel gasket. Copper coat was used on the gaskets and eventually wore away and leaked. There is barely 3 hours running time on the motor. I can just imagine what would have happened if the car had been driven for a prolonged period and the coolant started pouring into the oil. :jd:
Just wanted to pass this along in case anyone else runs into this head defect. They were replacement castings (the ones with the S1 on them) and not original 430 or 455 heads.
Now to figure out how to solve the problem on them or use different heads.

Thanks,
Mark

 

Coolant in oil

I just put my engine back together after it overheated and blew a head gasket. Now water is getting in the oil. When I drain the oil more water comes out than oil. Blowing on the radiator makes water come out. I don't know if the liar, drunk, mechanic I first took my car to actually had the heads pressure tested or not. Can a bad water pump leak coolant into the oil? This is frustrating. Oddly, one my 73 heads have a casting number that doesn't match the one used for 73. The casting number corresponds to a 72 casting number but it has a 73 stamped on it. If I overtorqued the bolts will this cause it to leak oil? I thought the torque wrench was set 100lbs but later found that when I was torqueing the intake bolts I had the torque wrench turned the wrong way(has a metric side-JC Whitney crap).

 

You should have prolly started a new thread with this problem........but without actually seeing the motor it's hard to diagnose this problem. The intake gasket is a good start, but cracked heads or block are also a possibility. That overtightened bolt is stretched and should be replaced, and I hope you didn't warp your intake manifold. Try pulling the spark plugs first and do a compression test.........a dead cylinder is a good clue to where a crack may exist. :bglasses:

 

Thanks,

I re-torqued the intake manifold and it still does it. I'll have the compression checked in a couple of days.