emulsified oil

Ok, here is the deal. I have a '90 Renix rig. I just put a '93 HO, head on it, and installed new injectors. Verified the torque settings on the head bolts and have run it now for about 500 miles. I have checked the oil every 100 miles or so and it has always checked out clear. At the same time, I have been keeping an eye on the coolant level and it hasn't moved, even a little.

So, I check it today and there is a slight white layer at the bottom of the dip stick. Coolant level is the same, I took off the oil fill cap and there is no sign of emulsified oil under the valve cover that I can see, so I am kinda stumped. The only thing I can think of is I recently took it through a car wash. Other than that I dunno what could be the source of the moisture.

Will gas in the oil cause emulsification? Could it be a bad injector? The only thing that would cause me to think its not the injectors is that the idle is super smooth. No hiccups or skips, just smooth, and I don't think there is a leak from the coolant to the cylinders. Cause there is no white smoke in the exhaust typical of burning off glycol.

Any ideas would be appreciated.

well with how cold it has been in your area recently, it might just be moisture from the cold. does it disappear after you run it and warm the engine? how much are we talking about here? if you had more than just moisture and a full on leak of coolant in the oil, the oil would turn to milk shake very quickly.
and gas would just mix into oil and thin it out. you would never see it.

The amount i noticed is about an 1/16th to an 1/8th of an inch at the very tip of the dip stick and today is the first day I noticed it so I just need to run it and see if it drys out.

Check to see that the CCV system is working correctly. No cracked hoses or stopped up tubes.

Good advice.

Cold weather, short trips and amount of miles on the oil can all play a part. Although you said you only have 500 miles after the head job, so that really isn't in play on this one.

Keeping CCV system clean on a RENIX is a must as they are more prone to blockage. Did you replace the two CCV hoses coming and going from your air cleaner when you did the head?

Car wash should have no relationship to this; no way for water intrusion into the engine with a simple wash. If you have a leaky injector, oftentimes you can smell the gas in the oil.

Run a simple compression test on all cylinders if you see any coolant loss. Keep an eagle eye on your coolant level of course.

That's initially how I saw the emulsified oil, through the CCV. One of the plastic hose pieces had cracked and when I was inspecting it I pulled off the rubber hose to the aircleaner. As I was pulling off the rubber hose the plastic hose broke into pieces and I saw a layer of emulsified oil inside the CCV hoses. Which lead me to check the dipstick and subsequently find the emulsified layer on the end of the dipstick.

I am assuming that the crack in the plastic hose on the ccv was there when I went through the car wash and thats why I was thinking that is where the moisture could have been introduced when I went through the car washes under carriage spray cycle.

So I will be replacing that entire plastic assembly anyways and probably change the oil after that is done and recheck often to see if it happens again. Or I could just by pass that plastic and just run a hose straight to the air cleaner.

Keithmania said:

So I will be replacing that entire plastic assembly anyways and probably change the oil after that is done and recheck often to see if it happens again. Or I could just by pass that plastic and just run a hose straight to the air cleaner.

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Just replace BOTH of the ccv hoses. And both grommets If one is failing, the other is surely not far behind it. They are not expensive; about $45 either from the dealer or aftermarket like NAPA. Don't bypass. Stay with oem engineering on this system.

By-passing the factory CCV hose, grommet system can cause never ending idle issue headaches. Stay with the OEM layout and tubing/hose sizes.

I have seen condensation from the dip stick tube do that, but it was not repeatable more than 2 or 3 times.

Did you notice that one head bolt has a different torque rating and is supposed to have sealant put on it's threads?

Draining the oil out is the best way to see for sure if there's coolant in it or not. If its fine you can just pour it back in, nothings lost but you'll know for sure one way or the other rather than guessing. If there is coolant in the oil it will burn up the bearings very quickly so dont mess around.

cruiser54 said:

Did you notice that one head bolt has a different torque rating and is supposed to have sealant put on it's threads?

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yep, its been awhile since i did it, but i believe its the exposed head bolt closest to the water neck that covers the thermostat. I might pull it and see if i put enough sealant on it...

robsjeepxj said:

Draining the oil out is the best way to see for sure if there's coolant in it or not. If its fine you can just pour it back in, nothings lost but you'll know for sure one way or the other rather than guessing. If there is coolant in the oil it will burn up the bearings very quickly so dont mess around.

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was planning on that this weekend, i gotta be sure that its not coolant related...

I think pulling that one head bolt may be a bad idea, since it violates the torque sequence rules?

Ecomike said:

I think pulling that one head bolt may be a bad idea, since it violates the torque sequence rules?

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If that head bolt is at the end of the head, I do not think it will affect the torque. Remember, the head is usually torqued from the center out in a circle usaually starting in an 'X' for the center 4 bolts then finishing at the extreme ends of the head.

Anyway, I have never looked at the torque procedures of the 4.0L so I may be way off base here.

That is a good point and true, but IIRC there were at least 2 if not 3 torque sequences, from about 30 to about 60 and finally to 110 ft-lbs, IIRC, that went from the center to the extremes in that circular path. I am no expert, but I know enough to ASK the question, can it lead to head gasket failure later, by removing and reinstalling just the one bolt. 5-90 might know?

Did a double check on the torque sequence and the exposed head bolt near the water neck, or bolt #11 in the sequence, is the bolt with the special torque rating. Here is the basic torque specs: First you torque all bolts to 22 ft/lbs, start the sequence over and torque to 45 ft/lbs, start again and torque to 110 ft/lbs, except for the #11 bolt which is only torqued to 100 ft/lbs. I believe it has a lesser torque rating because the head at that point is weaker with the bolt going through the water jacket.