Radiator fluid mixed with oil and major repairs lately

[RS4]

Long story:
Replaced main radiator 2 years ago after seeing white smoke from the tail pipe. SC radiator still good.

Recent: Check engine light twice: one was SC Gaskets that were shot. Other time was O2 sensor. Replaced entire rear differential which was annoying with only 55k miles. Maybe too much wheel hop over the years. Need to get better springs eventually! Had to replace all the heater lines which was weird. Need to rebuild the shocks next.

So back to the radiator. Flushed it 3 times and still oil in the radiator. Mechanic checked engine block and head gaskets and seem solid. Main oil is not contaminated and it clear thankfully. Engine temps remain stable but we can’t figure out the problem. Maybe just replace the heat exchanger or coolant tank? Gonna flush it again but hoping i don’t need a new radiator. Mechanic says to keep flushing it and it’s okay to drive as long as temps are good. I frantically check the oil to make sure it’s not contaminated but it’s good.

Any ideas and wtf is with this crazy maint on truck with 55k miles? Bought the truck 7 years ago with 3k miles.

 

[FordTechOne]

Most of your issue can be attributed to your modifications. Factory engine has no SC gaskets to fail. The factory axles are not designed to handle the additional power that the supercharger adds, and wheel hop only makes it worse. O2 sensors can also be carbon fouled if the tune isn’t perfect, especially if it’s tuned to run rich.

The most likely source of oil contaminating the coolant is the oil cooler. Oil pressure is typically higher than cooling system pressure, so oil will end up in the radiator. It’s also possible that the radiator has failed and is leaking transmission fluid into the coolant; you may want to check your transmission fluid level. The other possibility is an internal cylinder head or block crack that is allowing pressurized oil to enter a coolant passage, in which case the head or engine would need to be replaced.

How did the mechanic check the engine block and head gaskets? It is not a good idea to continue driving it, the oil will cause the hoses to disintegrate and swell, which eventually leads to failure.

 

[letsgetthisdone]

As ford tech one said, likely culprit will the oil cooler (mounted on the engine, the oil filter spins onto it) or the trans cooler inside the radiator.

 

[Canuck714]

Was it a factory Roush truck, or did somebody add the supercharger?
If its a factory radiator the Power Steering lines are also subject to failure at the tip of radiator, then the trans lines. As FT1 pointed out the oil cooler may be the culprit.
Question, how much oil is entering the coolant. Is it a noticeable drop in volume when you check the dipstick?

As for the rear diff. You have to keep in mind, when its unlocked its basically an open carrier that you are trying to push 600hp through! I had to replace mine at 80k, the shafts that the spider gears ride on showed excessive wear. I can only imagine it is from one side taking the force and the other spinning free most of the time.

 

[BoostedToy]

I have a 2013 Roush Raptor Stage II (serialized) that has 157k and counting and have experienced none of these issues. Other than an issue with the tensioner, which was resolved with a tune from VMP performance (you can search and read about my issue on that), the truck has been extremely reliable. That said, as you will also see, I agree with FTO on the fact that this 6.2, nor the drivetrain components, were not designed for forced induction.

With that, with diligent routine and preventative maintenance and importantly, not abusing the truck, it can be a reliable truck. I have a 22’ TRX as well that just arrived three weeks ago. Its obvious the truck was designed for a 700+ hp application with the engine and drivetrain components. The EB, as much guff as it catches, can make a lot of power and likely has a much higher margin of safety in its engineering than the 6.2.

Best of luck with your issues!

 

[1BAD454SSv2]

Oil cooler was leaking into coolant on my 2010 at 20,000 miles , softened up all my hoses. All Replaced under warranty in 2012. No issues since. Funny same type of oil cooler leaked on my 02 Lightning as well at same mileage new . Had droplets of oil floating in coolant .