poor 7, puking out its coolant guts
 

So, yesterday I'm driving back from Philly, and the coolant buzzer starts going on and off. The temp gauge is still reading normal, though, so I don't worry about it.

So today I turn the key in the "on" position to turn on the heater. Coolant buzzer is going off. I fill up with coolant, and the buzzer stops ringing. All is good, so I start driving.

About a block from my home, the buzzer goes off again. I look in the rearview mirror and don't see any coolant. Strange. Then I notice my temp gauge is like 3/4. Pull over, pop the hood, and I see coolant pouring out of the engine (seemed pointed downwards, not gushing out the side). There's water sprayed all over the driver's side of the engine like there was some kind of explosion of water (I guess coolant).

What do you think is wrong with my engine? I'm going to get under her and take a look later, but I just want some initial thoughts. Maybe a coolant hose just exploded or maybe my coolant seals are done? I have no idea.

I would say double check your old coolant lines, there should be a couple on the drivers side running from the back of the engine. That or go have your coolant system pressure tested.

first thing to do is check all the hoses. it is most likely a leak at a fitting or a hose has failed.

it doesn't sound like an internal leak from what you have described, so troubleshoot all the exterior coolant components first and let us know what you find.

the FSM has pretty good cooling system diagrams, check every single part you see and then mark it off on a printed diagram.

- Aaron

my best guess is that a coolent hose burst, these engines do run quite hot.

internal leaks dont show themselves until your car explodes and goes up into flames with you in it

Don't internal leaks show through bubbles in the coolant system? He might as well double check that while hes at it.

The heater hose coolant line on the drivers side of the engine is right underneath the oil filter pedestal. This line usually gets saturated in oil due to the aging o-rings that seal the pedestal, the oil leaks down onto the hose.
Point being, it gets weak, and with the coolant under pressure it will leak due to a crack or split.
Fill that bad boy up once more with coolant and run the engine to normal operating temperature with the hood up and just watch it. You can get the hose through mazdatrix or your dealer.

Ah, thanks everyone. I feel a whole lot better now. Back to the garage.

edit: But first, some vodka. ;)

yup...i went through 3 of these one time because of that...and the fact that it wasnt all the way up on the nipple on the engine, so the clamp kept tearing it. :rolleyes:

blackplague wins the prize for correctly diagnosing my problem. The hose had a nice little crack in it pretty close to the engine. Turned on the engine and saw coolant dripping out of there. Hope that's just it, but that still doesn't explain what looked like coolant just gushing out of the bottom of the engine. It literally looked like someone just took a bucket of coolant and dumped it out.

Also, anyone know of a better replacement hose? Like one resistant to oil. This coolant hose is $30 on mazdatrix and I would rather replace it with something that's not going to fail on me again if I'm going to have to spend that much money.

Same EXACT thing happened to me a month or 2 ago, it looked like a huge water balloon went off inside the drivers side. I would've put money that it was that hose too, but you've already confirmed it to be so.

Mazdatrix is the best place to get that hose, I looked all over and couldnt find much luck elsewhere. On quality the hose is OEM spec I believe.
The only thing you can do to prevent it being eaten by oil is be careful with your oil changes and fills, and make sure the filter and fill seals are fresh and good, or try and make something like an oil umbrella to prevent it from dripping on to the hose.

Maybe you can wrap the hose is something that will cause any oil spilt on it to run off?

Just throwing out ideas.

If you want to protect the hose take off the oil filter, and unbolt the oil filter pedestal and change the o-rings to brand new ones. Honestly, those two components when replaced will last another 20 years.

While your coolant system is drained, you want to change the coolant line that runs underneath the UIM (Upper Intake Manifold). You don't need any special line for this, just take it with you to an auto parts store. This goes from the firewall down to the top of the engine block, and it will be the next one to go. It will look like a coolant seal or something is leaking from the rear of your engine. Pain in the ass to diagnose. Now is the time to be pro-active! :)