My 86 Mazda b2000 is HEAVILY spraying coolant/water out of the radiator with cap off and out the reservoir with cap on, AS SOON AS I CRANK IT! Like there’s A LOT of pressure! About a week ago I saw a hole in a coolant hose. (The one that goes into the back of the motor) so I replaced it. Then I was driving and stopped because I noticed it was running hot. I then figured out that it was out of water. So I went and got water from the gas station and started pouring it in and OMG! I’ve never seen anything like it. It like exploded with steam! It just kept coming out! It did this for like 3 minutes solid. Then, not sure if it had anything to do with it, but I couldn’t get it to start. (My starter was going out) so I towed it home. I replaced the starter and got it to crank, but AS SOON as I did, it started exploding water/coolant from the reservoir. Took the cap off and it comes from the radiator. I’m at a loss cause there’s not much about this problem on the internet. The only thing I can guess is that air got in the hose. Can someone PLEASE help???

 

Welcome to the forum.

You overheated your engine, and the cylinder head is warped and the head gasket is blown......more than likely. You need to have a Mechanic's Shop remove the cylinder head and have it straightened & rebuilt, or, buy a new or remanufactured cylinder head and have it and a new head gasket installed. Do yourself a favor.......when this work is being done, replace ALL of the rubber coolant hoses with genuine new Mazda replacement hoses! They are worth the few more dollars they cost, compared to the China made rubber hoses that the normal parts stores carry.
Probably want to replace the Timing Belt, Idler, & Tensioner, as well as a new water pump also.

 

Doesn't sound good, carrying out a combustion gas test of the cooling system is the first step of diagnosis.