Oil in Coolant

[david85]

A bit disappointed today when I checked the fluids on my truck. Oil was fine but when I popped the rad cap, I saw even more oil! Oil in the coolant is very black, so not many places that could come from.

The truck still runs fine and no bubbles were seen after 20 min of idling with the rad cap off. So it looks like an oil cooler failure. The weather has been cooling off lately and I suspect this may have been the last straw. The O-rings currently in the cooler are as old as the engine rebuild (10 years ago, was it??), and came with the felpro gasket kit. All four of them were black, IIRC.

Anyway, I've been scouring the forum and have narrowed it down to two repair methods:

1. Remove the cooler as an assembly: Steering shaft, front drive shaft, inner fender, crossover pipe, driver's side exhaust manifold and anything else in the way will have to come out first. This allows the cooler to be easily removed and installed as an assembly. It also allows better access to prep the gasket surfaces on the block, particularly for the front manifold.

2. Remove the rear manifold and bundle only: The front manifold stays in place. Supposedly this eliminates nearly all of the extra dismantling with method 1. Assembly is done by prying with a 2x4 to compress the assembly back together onto the side of the engine. Seems like a nice alternative, if it works.

Does anyone have any nightmares to share about aftermarket parts on a job like this? I see that Dorman makes a new bundle and it comes with a gasket set. Open to suggested vendors from the forum as well. I like to support the community if I can.

 

[chillman88]

I bought my seals from Russ. Admittedly I haven't installed them yet, but they look good and I trust him to sell the good ones. He includes US shipping in his prices, not sure how much more it would cost to Canada though.

Oil Cooler Seal Kit

russrepair.com

 

[hacked89]

I use the felpro kits. I wouldn't do what you said in #2. Pull the cooler off, pry the heads off with flat heads, re assemble with a press preferable if you have one or access. Make sure it's straight. If there's a bunch of resistance and then a pop and it goes together that's the orings being damaged. The cooler heads can rotate doesn't really matter if you lose the position.

Also, don't let this go for any longer than necessary. Generally because the oil pressure is higher than the coolant system pressure you won't get coolant in the oil but it depends on how the rings fail I've seen it it go both ways. I just stripped a motor to the block and found water/oil mix under the crank to bearing even with the rest of the motor flushed out.

 

[quickster]

When I did my cooler I pulled the wheel, inner fender. Undid the motor mount, jacked up the engine, and with a few socket extensions removed the bolts. Might be a little tough to get it out. If so jack the engine a bit more. You'll need plenty of light to see what you're doing..

 

[gnathv]

Quickster has the right idea. I buy my oil cooler seals from Rockauto.

Victor Reinz gaskets
Mahle o rings

 

[Randy Bush]

I got mine Fel-Pro from Napa. Need need to make time and change them out. Any good ways to get rid of the oil in the radiator? Dawn soap?

 

[david85]

Its true that oil pressure will generally be higher than cooling system pressure. However, once you shut the truck off, you have ZERO oil pressure but still have cooling system pressure. So it's entirely possible for coolant to migrate into the oil during the cooldown period. The oil in my case doesn't look milky but that doesn't mean zero coolant made it into the oil.

That kit from Russ (@typ4 ) looks pretty good. I'm a big fan of viton, due to its thermal and chemical stability. I've seen how it holds up against automotive and industrial applications. The only failures I've ever seen were from a scratch or cut.

I'm not too worried about oil in the coolant, since it tends to end up in the overflow tank anyway. But yes, I have heard of running water and some dish soap to flush it out. Never tried it, but dish soap does work well as a hand degreaser, so I don't see why it wouldn't clean the cooling system out.

Alright, I'm not hearing much enthusiasm for the shortcut method. Not a big surprise, I suppose. Did any of you have to remove the exhaust manifold?

 

[chillman88]

Any good ways to get rid of the oil in the radiator? Dawn soap?

I've heard of lots of people running powdered cascade as a flush, then flushing it good with water. Your results may vary, but that's what I would try from what I've read.

 

[Old Goat]

When I did my cooler I pulled the wheel, inner fender. Undid the motor mount, jacked up the engine, and with a few socket extensions removed the bolts. Might be a little tough to get it out. If so jack the engine a bit more. You'll need plenty of light to see what you're doing..

This is sort of the way I did mine.
There is no reason to remove the Exhaust manifold.
Remove the front wheel.
Battery, Coolant bottle, window washer Bottle etc...
every thing on that side.
remove the 2 bolts for the Engine mount.
Jack up Engine and set on 2x4 block.
Remove the Cooler bolts front and rear.
Slide the Cooler out to the rear.

As far as the oil in the coolant. I used dawn Dish washing soap. I did 6 flushes, forget how much, maybe a cup each time.
Drive the truck getting it up to operating temp.
Drain Radiator, and the 2 Brass plugs on each side of the Engine.
Then once no oil was detected, I did 6 flushes with Distilled water. Each time getting her up to temp and drain.
Be sure Engine is cooled down before adding any cold water for a refill

Replaced the Heater Hoses and both Radiator Hoses. Also replaced the Block Heater, as I noticed it was green and oily around where it fits into the block.
When I removed it, the rubber "O" Ring was way past it`s life, and maybe the original 30yr old one.

With everything remove, good time to rip off the old fiberglass insulation on the inner fender, probably oil soaked and nasty. Also easy to replace the rubber Fuel hoses that run up to the original water separator which may have been replaced with another type, or the 2 hoses have been just connected together.
Be sure to wash out the Coolant Bottle.

Installing the Cooler "O" Rings, gave me the excuse to buy a 20 ton Press.
Make sure there is no nicks on the cooler headers. I polished mine with 1k, or 2K wet dry sand paper, and maybe WD-40 or something like that.

Good luck which ever way you go.
Here is to a leak proof Cooler...


Goat

 

[Big Bart]

I used the Mahle kit, the o-rings seemed well made. 2 years later no issues.

I have a 2wd drive, so yours will be a little different. I did not have to do much at all, I had to Jack the engine a little and loosen the brake line splitter. With some turning and trial and error I got it out.

In my case I noticed a little coolant came out (Couple of tablespoons.) on 2 different oil changes, but no oil in the radiator. The coolant would come out last, if you were not looking you would not even have seen it. So be careful you may have coolant sitting in your oil pan but it has not mixed together with the oil yet.

Gently clean the oil cooler ends and caps so the dirt and corrosion is gone but without putting deep scratches or nicks that will prevent the o-rings from seating and sealing. Use a o-ring lube to help them slide in place.(Help prevent pinching the gasket.) Some use Vasoline I use Dow Molykote. There are several other brands you could use. It likely also helps seal the o-rings.

Many of us use a hydraulic press to carefully push the two caps onto the oil cooler at the same time. I believe it was IDIBronco as I recall, had luck with a ratchet strap squeezing the ends on. They don’t easily go in, thus why leaving one cap on the block would be harder to do.

But a shop press is a very useful tool. (Wheel bearings, driveline bearings, u-joints, pulleys, et., etc., etc..) You can go with a cheap HF one that uses a bottle jack, but for a little more you can do one with a hydraulic ram with a pressure gauge and side pump. (Dake or Strongway for example.) I bought a higher end unit off an auction just to have a 40 ton. Not that I need that much but it’s there if I ever do.

I used some permatex high tack gasket sealer to help seal but also hold the paper block gaskets in place while I put the oil cooler back in.

Send some pics, let’s us know how it goes, and we are here if you need help!

 

[david85]

Thanks for all the support guys. Russ already contacted me in an Email so I'll probably go with his kit. It also looks like there won't be any shortcuts on this job.

 

[Old Goat]

I guess it is coming up on 3 years ago I did my Oil Cooler.
I searched to find a new Motor Craft Cooler. Lots of Dorman Chicom stuff. Found Rock Auto and Parts Geek had a remanufactured Motor Craft. Went with PG which seemed like the better deal. Picture showed Cooler with the gaskets.
came with no Gaskets or "O" Rings. They said it was a random picture. Had to search to find the parts.
Last time I bought from them.

I used Syl-Glide for the lube to get the rings to slide together.

Advance Auto Parts - Down for Maintenance

Goat

 

[Jim993]

Oil cooler failure is often the first sign that coolant has gotten acidic and corroded the relatively thin oil cooler tubes. A bit late, but start monitoring coolant condition with coolant test strips so that you do not have to do head gaskets. Consider adding a coolant filter with coolant adjustment chemistry or periodically adding supplemental coolant additive based upon test strip results.

 

[david85]

Oil cooler failure is often the first sign that coolant has gotten acidic and corroded the relatively thin oil cooler tubes. A bit late, but start monitoring coolant condition with coolant test strips so that you do not have to do head gaskets. Consider adding a coolant filter with coolant adjustment chemistry or periodically adding supplemental coolant additive based upon test strip results.

I'll check that when I tear into it. The seal kit is in the mail, courtesy of @typ4.

 

[david85]

According to the tracking number Russ sent me, the parts have arrived in Canada, so it shouldn't be too much longer now. With that in mind, I pulled the cooler this evening. Long story short, I'm not sure if I have a smoking gun just yet...

As for physically removing it, I was able to get access by removing the steering shaft, power steering pump and lifting the engine slightly. My truck is now basically an F350 4x4, so there was enough access through the wheel well without having to remove the wheel. Overall, it wasn't too bad, but lifting the engine was necessary. I also opened the drain plug on the rear header, rather than remove the block drain plug. Seemed to work well enough but there's always going to be something that spills.

The smaller O-Rings (that separate oil and coolant) are still pliable and not cracked. However, they are pitted from what looks like a buildup of deposits, so maybe this was a potential leak path.

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The larger O-Rings are heat cracked, but these only keep oil from leaking out onto the ground...which they weren't.

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Here you can see some of that corrosion that may have marred the smaller O-Rings. Similar pattern was found on both ends of the bundle.

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