I have recently bought a 2005 F350 XLT 6.0L diesel with 330,000 kms on it to pull my 6700lb camping trailer. When I test drove it, it ran very well with no leaks, no excessive black smoke and no white smoke, it has great power so I thought I had a winner.

The first time out hauling my camper and it blew a hole in the Coolant reservoir. The coolant is also brown with an oily emulsion. I checked the engine oil and their is no evidence of coolant there. The sprayed coolant smelled like varsol and had a really oily feel.

I replaced the coolant reservoir and filled it with water to get me home. The engine still makes great power and engine temp stayed in the normal range even while towing the trailer against the wind and up and down big hills.

Now I am trying to find out what is causing the brown slurry in the coolant? I understand it could be the oil cooler or the head gaskets. Is there a sure fire way to check if it is either one?

Does anyone know if there is a good diesel repair shop in Calgary Alberta that I can take the truck to, that is competent in dealing with Ford diesel trucks?

Thanks in advance for any help here.