GEN 1 Coolant Color - Is this Normal?

[Ikarah]

I bought this 2011 6.2L Ford Raptor about a month ago. I noticed first that the coolant had a brownish color to it in the reservoir but it didn't look like oil if I were to guess. Ford recommended I do a coolant flush, so I took it to the dealer and did exactly that. I've only driven about 200 miles since then. I looked at the reservoir again and it still looks brownish to me? When i look in the radiator though it looks green? Not sure what's going on. I added photos, any idea? I dont see any leaks coming from the car of any sort.

 

[Ikarah]

This is what I see on the radiator cap

 

[FordTechOne]

If the coolant is being contaminated with engine oil it will tend to accumulate in the expansion tank. Since they flushed it and the brown color has returned, it’s most likely still leaking. The most common location for oil to get into the coolant is the oil cooler, which is located at the oil filter.

 

[Ikarah]

What should I check for in this case? Is there a good route to diagnose this?

Edit: could it be also that the cooling system was just too dirty and one flush was not enough to clean it out?

 

[FordTechOne]

What should I check for in this case? Is there a good route to diagnose this?

Edit: could it be also that the cooling system was just too dirty and one flush was not enough to clean it out?

Not likely, coolant should never turn dark and oily. You can remove the coolant hoses from the oil cooler and see if there is oil buildup from it leaking.

 

[Ikarah]

So I just went to Ford, they claimed that the last technician did the flush incorrectly.. they cleaned everything and replaced the coolant. It looks clean now, I'll observe it over the next 200 miles again..

 

[Ikarah]

I took another look after driving around for a while. When I look in the expansion tank it looks clean but, the bottom is dark/black. Is the base of the expansion tank a darker color where it gets attached? I don't think there is oil there when I siphon coolant out its yellow and clear in a cup..

 

[Ruger]

I took another look after driving around for a while. When I look in the expansion tank it looks clean but, the bottom is dark/black. Is the base of the expansion tank a darker color where it gets attached? I don't think there is oil there when I siphon coolant out its yellow and clear in a cup..

Did you check the bottom of the expansion tank before driving it around? If not, it may be some residue from before.

 

[Ikarah]

Did you check the bottom of the expansion tank before driving it around? If not, it may be some residue from before.

I did, it looked the same it's like a dark base, I'll go back and ask the technician maybe there's residue there he couldn't clean off?

 

[Ruger]

I did, it looked the same it's like a dark base, I'll go back and ask the technician maybe there's residue there he couldn't clean off?

Get a pistol or rifle cleaning rod, and swab the bottom of the reservoir and see if that stuff comes away on a piece of old tee shirt.