Milky Oil

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Feb 2, 2016
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Alberta
My Car
71 Mustang 351C C6
Well guys, I fear the worst at this point. I got everything put back together and started up the engine. I could hear a bit of a ticking on the passenger side so I decided to check the oil (It has hydraulic lifters so could just need valve lash). I had changed the oil a couple weeks ago in preparation for this thing running. Remember this engine hasn't run for a couple years. When I checked the oil it had a thick milkiness to it. The engine had only been idling for 5 minutes, so that is total run time on the oil. Thoughts?

 
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Milky oil usually indicates antifreeze mixing with the oil. Did it seem like there was more fluid in the oil pan than when you started? IE was it over full on the dipstick? Did you get any white smoke from the tail pipes? Could be a blown head gasket or worse a cracked head.

 
No white smoke out the exhaust, but lots of white smoke out of that side of the engine. I'm guessing it is just drops of trans fluid from filling it so many times due to leaks. But what I'm really fearing is a cracked block (no real reason, just worst case scenario). A cracked head I can deal with cuz that will just give me an excuse to put some trick flow heads on.

 
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Oh and thinking on it. When I changed my oil I did notice for a split second it was clear, smelt like gas though so I just thought gas had settled in the bottom.
I had that problem and feared the worst but it turns out,if the temps are cooler and you run the engine for a short time,condensation builds up and it mixes with the oil causing a milky look.See if you can let it run for a bit to get up to operating temp and then check to see if it clears up,that worked for me.Good luck.

 
The split second clear when draining the oil was probably water.

The fuel smell could be from the fuel pump contaminating the oil.

I would pull the heads and have them checked you can usually spot the

cylinder that has been burning water.

Check for a bad head gasket.

If you have a cracked cylinder it will be apparent with the heads off.

Good Luck

Paul

 
A cracked block may look something like this.

Some ***** bored a Cleveland to 0.060!!!

Note the piston to the right, 0.040 yikes!

How could anyone abuse a Cleveland like that?

There otta be a law.

mike

HPIM2913.JPG

 
Are you losing water, take your radiator cap off and watch for bubbles.

If you don't see anything buy some cheap 10w40 and run it awhile and drop the oil again, see if it clears up. Your mechanical fuel pump could be pumping gas into the crankcase, good luck.

 
Thanks guys, I think I have a plan of attack. I watched a video where a guy used compressed air in the spark plug hole and watched radiator coolant level. I realize you need to turn over the engine to get the intake and exhaust closed, but thought this was a good idea to test head gaskets anyways.

I've always had to add coolant every year but I don't have an overflow so I figured it just bubbled out. I really think it has to do with sitting for so long. All gaskets in the water pump/timing chain were replaced when I put in the cam but I never did pull the heads. So those gaskets are probably pretty old. Plus I can't remember if I had single keeper valves or not so may be a good time to change them if they aren't.

Fuel pump was also replaced in the last couple years, so for that I just wonder if a float bowl stuck or when I had issues starting it that let all the gas in the oil.

I'll keep you guys updated when I get at it, all I'm hoping is that it isn't a cracked block but a friend made a good point that none of my frost plugs pushed out.

 
milky oil means it has a LOT of water . if it was leaking that much into a cylinder it would usually steam out the exhaust..

 
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vozaday, did you pull the plugs and were any 'wet'? Rather than messing with the compressed air, I would try a compression test first. If you find a cyl or two is low then you pretty much have to pull the heads no matter what the issue might be. Remove the spark plug wires, crank it for about 10 seconds and then pull the plugs and see if any are wet.

Barnett keep in mind it is a Cleveland, no water passages in the intake.

 
Not much to add tonight. I pulled 7 plugs and they all looked the same. A lot of carbon build up and 2 had slightly wet oily threads but other than that nothing out of the ordinary. I replaced the battery (old one was failing) and realized the cables were stuck on the posts. So no compression test tonight.

 
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So, sorry to see this and a few comments and thoughts.

The "frost" plugs as you called them, or "freeze" plugs as they are often called are really not as their name implies. They are part of the casting process to remove sand from the finished casting- the fact they didn't pop means nothing.

Antifreeze is extremely hard on bearings. If you haven't drained the oil and put in fresh oil already, it is your next step unless you are going to tear the whole thing down. Determing whether it is gas or antifreeze contaminating your oil is the determining factor for the next step.

If Gas, rebuild the carb and check the fuel pump for leaks.

If it is antifreeze-you can try a block seal product, or you can go straight to pulling the heads and looking for head gasket issues.

If the heads haven't been rebuilt before, it is probably a good idea to get some modern 1 piece valves with single groove keepers and get them rebuilt.

Good luck

 
Ok update.

Compression test. This was done on a cold engine.

1-135psi

2-140psi

3-141psi

4-145psi

5-140psi

6-137psi

7-135psi

8-137psi.

Other than cylinder 4 being a little higher than expected they don't seem too far out. Any other ideas?

 
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Did another quick test on cylinder 4 as it was the first one I did and was curious why it was so much higher. Well it came in at 151psi the second time. Could it be that the cylinder is filling and since it didn't have a spark plug in it to push fluid past the rings it filled up and increased compression?

Edit: thought about it a bit. Could also have been fuel that made a better ring seal.

 
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Decided to take off the valve cover to find the ticking noise. Found this. IMG_6604.jpg

So theres that.

I hooked up an air compressor to a couple cylinders but no coolant rose. So coming from a limited understanding of the cleveland and never taken the heads off before. Can the coolant mix with the oil at the head gaskets without involving the cylinders?

I tried to take off the spring to check what type of valves I had but my spring compressor would not work for multiple springs..... since I already had the air hooked up, guess i'll have to find another one.

 
if those are chinese rockers i would replace them all.

turn the engine over and see if the rockers are hitting the springs or retainers.

.

 
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They are Comp Cams, found a couple that broke like this online. It's a simple fix but thought I would post it anyways. Glad it wasn't rod knock.

Trying to decide if I should just use coolant stop leak and try it out or just say screw it and change out the head gaskets and timing gasket.

 
They are Comp Cams, found a couple that broke like this online. It's a simple fix but thought I would post it anyways. Glad it wasn't rod knock.

Trying to decide if I should just use coolant stop leak and try it out or just say screw it and change out the head gaskets and timing gasket.
ok, well those rockers are made in india.

if it did not leak water before and all you did was change the head gaskets, the logical place to start would be there but there is no indication of them leaking water.

i have had a few timing covers leak water into the oil . the last one had a hole eaten thru the steel plate.

 
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