my vehicle is overheating, I have exhaust pressure in the radiator, the coolant is being forced out threw the overflow tank. Does anyone have any ideas what might cause this and the fix for it.

 

Sorry to say but I think you might have a exhaust leak in to your water jacket. You need a new engine. Please give us the history on your car. The service it's had and parts replaced. Miles..etc

 

85,000k, could it be a blown gasket, hate to think it might need a new engine

 

Where are you? There is no "location"....What is the warranty of the engine in your country....call your local dealer. It most likely is a gasket or seal the problem is it requires much labor and parts to fix. I see you put 85k so I would make a guess you are not in the U.S. In the U.S. Mazda gave us a 8 year 100K miles warranty on the engine.

 

US, Texas spoke with a dealer and no warranty, thanks for your inside.

 

Mazda warranty covers the engine 8yrs 100k. Now you said 85,000K, so what you ment was 85K miles. Call Mazda North America and see if you are covered. You should be....they will need your Vin#.

 

Agreed. Unless somehow the car got flagged for not being able to receive the engine warranty, but I can't see that being the case. MNAO will be able to sort this for ya.

 

sounds like your engine is pretty much toast.
be prepared to have the dealership ask you for service records / proof of maintenance. You might need to show that maintenance was performed at regular intervals (ie' every 3,000 miles)