TR4/4A Oh crud - coolant in the oil

[sp53]

So the oil did not look like a milk shake after all? And there was no crud in the oil? I would take the thermostat out and see what happens and I would look for a plugged radiator. At 200 miles the oil should still be clean.

 

[tdskip]

Good morning and thanks for the help.

So the oil did not look like a milk shake after all?

Turns out no milkshake. Oil was dirty looking but this was a fresh rebuild and not sure if that was just initial assembly lube.

And there was no crud in the oil?

no crud

I would take the thermostat out and see what happens and I would look for a plugged radiator.

Radiator was re-cored prior to being installed, but worth checking since maybe something came loose in the block water passages. There was some red-ish pebbly material on the radiator cap.

 

[2long]

Any chance that some form of red sealing material was used for the head gasket, and some extra oozed out and into the cooling system? Just a WAG.

Dan

 

[tdskip]

Aloha Dan. Might be, didn't seem metallic.

In doing some research it seems that antifreeze won't necessarily milkshake like water will. Is that accurate?

 

[JerryVV]

I've had it happen in 4.3 Blazer and yes it does look like a milkshake when mixed with oil. And hard to drain out as well. You are fortunate it did not get into the oil. How did the combustion gas test turn out. That test will confirm very quickly if the head gasket is leaking and over pressurizing the cooling system.

JVV

 

[tdskip]

Hi guys - slow in providing an update on this but the news is not good.

I finally got around to pouring the oil I drained out of the 4a and after it had sat for last 45 days or so it clearly separated and there was crud in the bottom of the trays (I used several to drain the oil into) and there was a clear separation of the oil and coolant in the last one I poured into the larger tray.

Apparently the oil will not always froth, so be aware.

Sigh.

 

[JerryVV]

Maybe you caught it before the oil and coolant had a chance to mix and milkshake. That would be good news for your bearings, you never said how the combustion gas test turned out. That may be moot now that you found water in the oil. Pull the head and replace the head gasket.

 

[tdskip]

Maybe you caught it before the oil and coolant had a chance to mix and milkshake. That would be good news for your bearings, you never said how the combustion gas test turned out. That may be moot now that you found water in the oil. Pull the head and replace the head gasket.

Hi Jerry - thanks for the note back. Hoping I caught it in time, going to start tearing it down later today. Nothing to do but dive in I suppose.

 

[sp53]

I re-read your thread, and I would have the head checked for cracks while it is off.

 

[tdskip]

Good suggestion - thank you.

Should of been done at time of rebuild - only hundreds if miles ago - but who knows...

 

[TuffTR250]

BTW, the original aluminum plug in the top of the head, per Moss Tech Support, is 1 inch diameter and has 14 threads per inch SAE, and is 3/8 inch thick. It is not pipe thread.
Bob

 

[TR3driver]

Maybe not, but a 3/4" pipe plug will screw in and seal. The head on my previous TR3A was done that way before I got it, and never leaked again.

 

[Deleted member 8987]

If the oil drained as just oil, why did you think you had coolant in the oil?
Just asking, as there is probably more to this story.

 

[mrv8q]

I hope it hasn't taken Tom 13 months to diagnose the problem...