Why oil seems to be almost "milky" after EFI swap?

[monk302]

So I have be running my engine after having just completed my EFI swap. It appears as if the oil on the dipstick appears to be "milky." What would make this happen. Would it be from antifreeze somehow getting into the oil? I would appreciate any opinions.

 

[gsxrken]

yes, water from the intake is likely getting in. You probably need to reseal your intake manifold. Also make sure your thermostat is allowing the engine to come up to temp, around 180-190 F degrees or so.

 

[krash kendall]

What year heads are using? If pre-1976 you will have to use early 302 intake gaskets. They should work fine with the later manifold, but the later gaskets will not work with the early heads.

Hey, 1000 posts!

 

[66StangFastback]

I had a milky substance in my oil after rebuilding the engine. It was only the lube used on the bearings,cam and such though.

 

[monk302]

What year heads are using? If pre-1976 you will have to use early 302 intake gaskets. They should work fine with the later manifold, but the later gaskets will not work with the early heads.

Hey, 1000 posts!

Hey Krash,

I am using re-1976 heads. So you are saying I need pre-1976 gaskets huh. That may be the problem then. I have had issues with leaking antifreeze this entire time. I thought I solved it last time by repositioning the gasket but now I think the fluid may be instead going into the lifter valley.

Thanks,

Mike

 

[krash kendall]

When you lay the later gaskets on the head they look like they are lining up with the end cooling journals, however there is less than 1/16" (if any) coverage. They will leak at the driver's side rear or passenger side front, most likely. My neighbour and I both made this mistake on our cars within a month of each other. He did it first, so he knew exactly what my problem was when it happened to me after putting a new intake and carb on.

 

[monk302]

When you lay the later gaskets on the head they look like they are lining up with the end cooling journals, however there is less than 1/16" (if any) coverage. They will leak at the driver's side rear or passenger side front, most likely. My neighbour and I both made this mistake on our cars within a month of each other. He did it first, so he knew exactly what my problem was when it happened to me after putting a new intake and carb on.

Precisely what happened to mine the first time I installed. Was leaking on the rear driver side. I guess now it is just flowing into the lifter valley area. Off to get new gaskets this week I guess.

 

[krash kendall]

Well, its been a few days now. Any progress?

 

[monk302]

Well, its been a few days now. Any progress?

Actually going to take the top end of the engine off this afternoon with the gaskets hopefully arriving around 4:30. Should have it back together sometime tomorrow. I will keep ya filled in.

 

[monk302]

So today I bought a case of some generic motor oil and Marvel Mystery Oil. Got home and drained my oil pan and immediately antifreeze came out for a few seconds followed by my "milky oil." Took off filter, put new one on, and then put five new quarts of generic oil in along with Marvel Mystery Oil. I ran it for about 15 mins and tomorrow I am going to drain oil, put another filter on, put good Exxon Oil in and hope for the best.

 

[krash kendall]

But you didn't change the gaskets?

Pouring some magic elixer into the sump won't "fix" anything. If there is enough coolant getting in the pan for it to stratify in the manner you describe then you run a high risk of hydraulic-ing the motor and destroying it.

 

[66moneypit]

That mystery oil probably isn't going to fix the problem.

Now it is possible that you got alot of antifreeze in the lifter valley when you took the old intake off. It's definitely a good idea to change the oil when you change the intake for that reason. I don't know if you could get enough to cause the milky oil though.

I would definitely redo the intake. It's a pain but worth it. My concern with that mystery oil is.....if it's stopping the leak...what else is it stopping ?

 

[Steve69]

Did you get your engine up to temprature. Mine had the same thing
And I thought it was the manifold also. It was just alot of cold starts
and Idle time that caused my problem. As soon as my Mustang was road
worthy I changed the oil and ran it on the highway and never had the
problem again. I would try this first before taking the manifold off.

 

[66moneypit]

That's a good point, you might try getting it up to temp and then retorque your intake bolts. Mine settled and needed to be retightened a few times.

 

[krash kendall]

Guys, he had a stratified layer of antifreeze under the oil that took a few seconds to pour out before he saw any oil. This is not a condensation issue. I guarrantee he has the wrong intake gaskets for those heads!

 

[monk302]

Guys, he had a stratified layer of antifreeze under the oil that took a few seconds to pour out before he saw any oil. This is not a condensation issue. I guarrantee he has the wrong intake gaskets for those heads!

Sorry for being unclear. I did take off the manifold and replace the gasket with a pre-1976 gasket. Then, from that point I have run the oil and plan on replacing it again this evening. So far I have not seen any indications of coolant leak since I have replaced the gasket. Krash was right on the money.

 

[krash kendall]

Phew! You had me worried there!