The Stovebolt Site Forums The Shop Area Engine Shop Oil in the radiator

This week I purchased a 60’ Apache fleet side short bed with what I assume is the original straight 6. The truck is the same age as I am and it looks like it might be in a little better shape. The extent of my experience with old trucks was owning a 49’ Willys flat grille pick up back in high school so forgive me if the questions are a bit basic.

After 10 miles of driving I have discovered oil in the radiator. Back in 05 there was one string posted here on this subject with lots of possible causes but the owner didn’t post the outcome. There is no water in the oil and it has what looks like a new water pump so I’m hoping it is something related. Any one out there have this come up before?

This truck was also lowered in what I expect is the normal fashion. Blocks and shims between the rear axel and springs and in the front, the nut on the stud retaining the torsion bar lever arms have been backed off almost to the end of the thread. I had intended to simply remove the blocks and tighten the torsion bars back down. Is there a spec for this or anything I should look out for?

Thanks,

Bob J

Bob, welcome to the bolt, I am sure someone will help,, I have never seen this problem with oil in the radiator........but... I am sure even at 66 they are a lot of things I have not seen..

sure wish I was in Huntington, Beach. we had a chance to visit there about 2 yrs ago.. what a great place.. would love to live there.

Joker,
Mesquite has it's moments. Every couple of years we go back to Comanche for the family reunion (this weekend I think) and a few years back my older brother moved to Decatur.

Bob J

If it,s an auto trans. it could have a leak in the cooler. Other then that, with the original type 6 cyl. it would be very rare. Being you just got it I would flush it out real good & refill it & see what happens. It could have gotten put in by mistake. If it has the later model 6 cyl. (63 up) they are noted to crack in the lifter gallery & cause that.

It is a 3 speed manual. We have not ID the motor yet but plan to do so today. I think we will be flushing the cooling system today rather than removing the drop kit.

Thanks,

Bob J

Have you changed the oil and inspected it? If not, how do you know there is no water in the oil? I'd pull the valve cover and see if the inside of it is milky looking and if there is a build up of greasy crud. That would indicate a leaking head gasket which is what I suspect you have.

How do you know there's oil in the coolant? Is it frothy? I've never seen oil go to the coolant on a manual trans. Coolant pressures would push it into the oil,
Scott

I checked the dip stick and the oil was not contaminated. I know there is oil in the coolant because when I was checking the coolant levek it looked odd. I stuck my finger into the coolant and it came out covered in oil.
I had the radiator flushed this afternoon and am waiting for it to cool off a bit before checking the coolant again. If in fact there is still oil present how on earth do I definitively isolate the cause of the problem?

Thanks,

Bob J

Don't know if this will help, but I found what appeared to be engine oil in the coolant recovery tank on one of our ranch trucks. Turned out a bottle of Barr's Leak had been added to cure a pinhole leak in the radiator and it wound up in the recovery tank. It looked and smelled like cruddy engine oil.

A radiator pressure test might help shed some light on the situation.

Dave

Dave,
I just checked it again after having the coolant changed and there is still oil although it seems there is less now. Sounds like I'm off to the radiator shop! There is a new water pump, hoses, and the radiator is freshly painted black so Barr's Leak might be consistent with someone trying to fix a leak.

Thanks,

Bob J

Bob,

As Wrenchbender alluded to, there are almost no scenarios that would introduce oil into the coolant other and a leaking transmission cooler, and yours isn't a automatic.

The most likely cause would be a greenhorn adding oil to the engine, and mistakenly dumping some into the radiator!

For any internal oil exchange to take place, oil pressure would have to be greater than coolant pressure. When the rig was shut off, oil pressure drops to zero while cooling system pressure remains. This would result in coolant being forced into the engine, and the resulting milkshake would be a dead giveaway.

Taking your radiator to the shop when it doesn't leak coolant won't prove anything. The block has nooks and crannies that will hold junk, so you will probably have to flush your system a few more times.

As I recall, Bars Leak looks nothing like motor oil in the radiator. Its initial color is white..like soluble oil, but then that dissipates as the pellets are dissolved.


Stuart

I beg to differ with some of our more experienced contributers. Though it was not a 235, but a 292, I had a crack between #3 and #4 cylinders above the oil gallery that put oil in the cooling system, no water in the oil. I drove it that way for a few thou. I don't remember how I determined exactly where it was, unless it was after the thermostat stuck, then there was water in the oil.

It maybe rare but

Larry

The stuff in my coolant isn't any type of soluble oil that I've ever seen. It beads and floats and looks just like motor oil. I think a little more aggressive pressurized flush of the coolant system may be the next step.
Thanks for all the input. I can see that stovebolt is going to be a valuable resource for us while we (we being my 16 year old daughter and I) play with this. The down side to this little father daughter project is that she already has designs on the beast. My office is 1.8 miles away and this truck was intended to be my every day driver but I'm betting I'll be driving her Volvo as much as she does.

Your right Griff. That,s why this old timer mentioned the 63 & later 6,s were noted for getting oil in the coolant. It comes from a crack in the lifter gallery & there is no cure except replace the engine.

I bought a 1953 chevy 1/2 ton parts truck that had a lot of oil in the radiator like you describe. When I took it apart, I found the copper tube that goes from the bottom of the engine to the rockers had been routed between the top of the block and the head. Of coursed this "squished" the oil line and let the oil flow through the water jacket. I replaced the oil line, flushed the water and it ran nicely. I don't know if your motor has this oil line, but strange things happen to these old machines. Good luck!

Hey, Wrenchbender missed that OOOpps.

Larry

My '67 250 with manual 3 speed trans started pumping oil in the coolant. Globs of oil and whiteish foamy stuff floating around in the coolant. I continued to drive it everyday for a while, but eventually had too much trouble with the thermostat plugging up. Radiator was plugging also. Absolutely no signs of coolant in the oil.

Old time mechanic who was also my next door neighbor upon hearing my description of the symptom, right off the bat said cracked oil galley. So I bought a rebuilt and plopped it in.

If it still has the original engine, it should be a 235. But it will be the later 235 without the oil supply tube to the rockers. There was a design change (I forget exactly what year, '58?) that eliminated the line with a drilled passage in the block. I could see where one could have the same problem if the gasket failed beetween where the oil passes to the head and a water passage.

Cylinder wall crack? Any steam out the tailpipe?
A great mystery. When you figure it out let us know. Some of us may go down that road ourselves some day.

I had an '82 GMC 1/2 ton manual trans with a 250 six and the integral manifold head that developed oil in the water and water in the oil (butterscotch stuff clinging to the oil stick) But it never lost any oil from the sump or water from the radiator.

I was only driving it a short distance daily in a high humidity area (New Orleans) and almost never long enough to warme it up. And it still was running fine. Although I swapped it out for a 283, I always figured that condensation might have something to do with it.

It seems that the problem is either totally innocuous or totally catastrophic. Either way, it isn't likely to get worse. Since the oil in the motor is clean and the oil in the radiator doesn't seem to be bothering anyone, and the fact that my office is 1.8 miles from home, I'll just ignore it for now and revisit the issue if it gets worse. Thanks again for all the input and I'll update the post when/if I discover the source of the mystery oil.

Bob J

Many people would add oil to the coolant for lubrication of the water pump bearings. Are you sure it isn't just that. You may want to contact the previous owner just to ask if he may have added oil to the coolant for that reason.

If that is the case, I wouldn't worry about it.