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Discussion Starter · #1 ·
I just got an engine running that I rebuilt a few months ago. I just put oil in it a couple weeks ago. I fired it up tonight and ran it for 30 seconds or less, at which point I noticed my oil was the milky color of water and oil mixing. I want to know from the experienced builders if running the engine for this long will have damaged the engine already? I'm going to drain the oil and swap the filter tomorrow... But, am I going to have to pull the whole thing out again?
 

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Did you clean the block with anything during the build? Something worth trying would be to change the oil & filter and give it another short run to see if it happens again. It may have been foreign fluids in the block from the rebuild. If you get the same result, then you may have a headgasket issue. An oil change would a lot cheaper then pulling the motor apart to diagnose. I dout any damage occurred during the motor warm up with no load on the motor for the short run time
 

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Discussion Starter · #3 ·
Yeah, I will be trying fresh oil tomorrow, or Sunday. I don't see how water could have gotten in, unless there is a bad head or intake gasket... I can't imagine that it was condensation build up over the winter.
 

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No i would not think that it would hurt your motor. Like josh89 says, just change the oil.
And when you say rebuilt, do you mean, just replaced all the gaskets?
Im sure that you know that when you replace a headgasket you really should check the heads for straightness and make sure they aren't warped. Usually a machine shop is A-lot more accurate then the naked eye or basic stick ruler.
 

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Discussion Starter · #5 ·
This isn't my first time. I stripped this thing to the ground and built it back up. Crank was good, heads were cleaned, magnifluxed, and surfaced. Valves were ground, new guides were installed. New cam and lifters. New bearings all the way around. New freeze plugs. New rings. New timing chain and gears. New gaskets. This is my 4th build.

I drained the oil last night and put fresh oil and filter in today. Started it back up and milky oil all over again. This isn't an LT1, it's an old engine with the standard manifold water crossover ports. I'm hoping it isn't cracked. But, now it's time to tear into it and find out what the culprit is. Hopefully, it's just a slipped gasket.
 

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I bet one of the gaskets slipped like u said. And yes that does make since.
Just when u put it back together, be sure to use the torque wrench and follow The right torque patterns for thr heads and intake. ( im sure you know all ready )
 

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Discussion Starter · #7 ·
Yeah. I'll pop the manifold off tomorrow night. If that doesn't yield any info, I'll pull the heads the next day... Or perhaps that night. With airtools, it doesn't take long to remove 7 bolts.
 

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Exactly haha. Just let us know whats up.
 

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Discussion Starter · #9 ·
Pulling off the intake didn't reveal the leak. The mating surfaces of the head and intake were still pretty clean between the coolant ports.... There is still a noticeable mix of water in the oil, even though the engine has sat for a few days. The cam and lifters look clean as could be... No rust forming from the water that was being mixed with the oil.
 

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Discussion Starter · #11 ·
It's not even a Gm vehicle. It's an old dodge truck engine. I'm just looking for general knowledge from other, more experienced engine builders.

On that note, I pulled off the driver side head. There was only an indication of water and oil mixed in one of the head bolt holes. But, I couldn't tell that any water was getting through the ports... And the gasket was fine. I'll take a look at the other side tomorrow.
 

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Discussion Starter · #12 ·
Well, after looking around, I haven't noticed anything indicating water getting into the engine. Last night, I started really thinking about it. I never even ran the engine long enough to allow the thermostat to open... So, it's unlikely water was getting into the engine anyway. Not only that, but there is no oil/water separation that should be occurring after once the engine is turned off for a while... I'm starting to expect the red lithium grease that was used on the cam lobes and journals when I installed. Why did I use this, you may ask? Because, after I ran out of assembly lube I got online to look up grease usage on bearings and read information that people have been successfully using lithium greases for cam break in for years. I also found people saying it caused problems. The cam looks good as it sits in the engine. I've seen lots of lubricant squirting atop the lifters and up the sides of the pushrods. However, I haven't seen any coming up to the rockers. When I pulled the pushrods, I didn't see any holes. They are solid tips. That can't be right, could it?
 
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