Oil in my radiator

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Dartsun

Dartsun

Mopar Dude
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After initial engine and cam break in on my 66 273 hipo rebuild I noticed that there is oil in the radiator. Can this be caused by an intake leak or is it more likely a head gasket failure. It doesn't smoke but it did smoke for a few minutes out of the passenger side on initial break in. Thanks Dustin
 
Auto or stick? If auto could be the cooling line inside the Rad. Common.
 
It is an auto. My tranny fluid has stayed pretty level but my engine oil is always at or close to the fill line.
 
how does your tranny oil look like ? like Strawberry milkshake ? Then the tranny is involved.... If the engine oil looks like capuccino.... then you have a gasket problem in the engine.... or even worse a crack..
Greetings Juergen
 
Pressure test it to 15psi, or more if you dare.
If it holds, flush the system, refill with water, drive it for a few hours. Let her cool, pop the cap blot the crud out, cap it and more run-time. Repeat as often as necessary to get the crud out.
But if the oil remains or gets worse, then you will have to do a cylinder air pressure test (about 80 psi) with the pistons at exactly TDC.
And if that fails to prove anything, then that test will have to be repeated, but with the pistons at BDC. To do this the rocker arm shafts will have to be removed, or the bolts at least completely backed off, so the valves are closed.Also,in this position you can crank the pressure to the moon! If you find a leaker, check the rad.........
After the problem is repaired, don't forget to dump the water out of the cooling system,before winter....
 
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how clean were the engine & radiator when the motor was reinstalled? you could try flushing the cooling system clean and starting over.
how much oil are we talking? clean oil? dirty oil?
 
vitamindart said:
how clean were the engine & radiator when the motor was reinstalled? you could try flushing the cooling system clean and starting over.
how much oil are we talking? clean oil? dirty oil?
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The engine was quite clean the radiator came out of the car to begin and was fairly clean daily driver. I'll post a pic of the coolant tonight after work. Thanks for the advice and tips. Dustin
 
Does the engine oil level go down? Does the trans oil level go down? If not I would think it was in radiator before. Oil is lighter than water or coolant so it will be at the top. Also I would suck it out of the top instead of drain radiator so you don't get it in whole radiator. Doesn't take much oil in top to make you nervous so you might not have much contamination. You can buy suck gun from parts store pretty cheap.
 
Too long a bolt in a rocker arm stand could have caused a crack that slowly feeds oil into a cooling passage.... just a SWAG.
 
gnr said:
Does the engine oil level go down? Does the trans oil level go down? If not I would think it was in radiator before. Oil is lighter than water or coolant so it will be at the top. Also I would suck it out of the top instead of drain radiator so you don't get it in whole radiator. Doesn't take much oil in top to make you nervous so you might not have much contamination. You can buy suck gun from parts store pretty cheap.
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Trans level is good engine oil goes down but I'm chasing a oil filter adapter leak also. And your exactly right it's not a lot of oil but it does make me nervous. Good idea about not draining the oil all they the system suck it out of top. Thanks Dustin
 
Try doing the flush thing see if it goes away, was the block fully cleaned/hot tanked when the engine was rebuilt? If not there could have been oil that dripped down into the cooling passages when the block was turned over on the engine stand... kind of a "left field" cause but it sure would be nice if that was the case!
 
Yes the block was cleaned and hot tanked. I ran a compression test and it was 135 across all 8 which doesn't seem to high for a new engine. Did a leak down test on the radiator for exhaust gas and it was good. That's what my finger looks like when dip it in radiator. Dustin
image.jpeg
 
Although that does not look good, do a GOOD cooling system flush, including the engine and radiator. Remove the thermostat so that you can flush with no restriction. FLush the entire system until it is sparkling clean. Put water back in and start it up. It's possible it was left in the radiator and or in the crevasses in the block's cooling passages. Flushing the system costs nothing and may fix it.
 
RustyRatRod said:
Although that does not look good, do a GOOD cooling system flush, including the engine and radiator. Remove the thermostat so that you can flush with no restriction. FLush the entire system until it is sparkling clean. Put water back in and start it up. It's possible it was left in the radiator and or in the crevasses in the block's cooling passages. Flushing the system costs nothing and may fix it.
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Thanks Rusty it's worth a try. Dustin
 
RustyRatRod said:
Although that does not look good, do a GOOD cooling system flush, including the engine and radiator. Remove the thermostat so that you can flush with no restriction. FLush the entire system until it is sparkling clean. Put water back in and start it up. It's possible it was left in the radiator and or in the crevasses in the block's cooling passages. Flushing the system costs nothing and may fix it.
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X2!!!
 
Does not look good. That is not from a tiny amount of oil. Drain the oil pan right away and see if any coolant comes out with the first stuff that drains. You may needs to let is set for a while and then slowly pour the oil off a bit at a time without shaking the pan to see if some coolant is residual in the bottom.

If no coolant in the pan, then I would be suspecting a crack from a pressurizing oil passage into the water jacket.

But do the drains and cleans first. I'd use some Calgon dishwashing detergent in water in the cooling system a couple of times and flush it clean with water afterwards to get the oil all out.
 
When a engine is running the higher pressure oil would go into the lower pressure water. When a hot engine stops the residual pressured water goes into the zero pressured oil. Soooo, the very first thing I would do is drain the pan and look for water in the oil.
Now me... I recycle to reuse coolant whenever I can. My very best method/effort doesn't always get 100% of the oil out of that coolant. What oil that does remain ends up in the coolant recovery bottle. After pulling it and washing it out a couple times, its all clean again. Of course the small amounts added are always virgin stuff.
If you didn't reuse coolant, didn't use a oily funnel, don't have any other explanation, I don't have one either. good luck though.
 
Dartsun said:
After initial engine and cam break in on my 66 273 hipo rebuild I noticed that there is oil in the radiator. Can this be caused by an intake leak or is it more likely a head gasket failure. It doesn't smoke but it did smoke for a few minutes out of the passenger side on initial break in. Thanks Dustin
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It's been a while back, but I had that happen to me twice, I think I only had the timing cover off both times. But I don't know what I did wrong either.
I drained the oil and put it in empty clear one gallon water jugs and checked it out. No antifreeze in the oil both times.
Added coolant and soaked the oil off the top of the radiator coolant with a rag.
Fired it up, no more oil in the coolant, and no problems. And the awful feeling of Panic was gone too.
 
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