I just went for a "spirited" ride in my S4 and about 1/2 mile from my house the "add coolant" warning buzzer sounded. I limped her in and smelled coolant burning, opened the hood and there was coolant spray over the driver side engine bay.

While I let her cool down before getting in there to look....do you know what may have happen? The engine has 203,000k on the engine. Just got her about 3 weeks ago, did a tune up (oil&filter, fuel filter, plugs&wires, O2 sensor).

Thanks for looking.

Dave

 

Find where the leak came from. Based on the little info you gave, an S4 NA will have coolant lines for the heater and BAC on the driver-side of the engine. If any have burst, do not drive the car until they can be replaced. Top off the coolant and bleed the system of any air with the screw on the radiator.

 

Once I got in there, I figured there was a busted hose right underneath the temperature sender by the oil filter.

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The previous owner used a copper "U" shaped connector. I'm not sure mazda used copper parts? hehe anyways I replaced the hose and added coolant and took her for a spin.

That problem is corrected but, now when I open up the radiator filler cap there is a steady leaky stream of coolant coming from the middle of the engine bay. I haven't lifted the car up yet but, has anyone or does anyone know why releasing the pressure would cause a big leak and where?

Thanks for your help.

Dave

 

So I lifted the car up and noticed the steady leak coming from underneath the water pump after I open up one for the coolant filler caps. After lots of thread surfing here on our forum, I believe the leak is coming from the water pump "weep" hole. This is a new development occurring after the hose under the temp sensor bursted open and refilling the coolant.

I was wondering if I refilled the system coolant improperly causing air bubbles in my system and possibly exiting through the "weep" hole or did my water cooler just take a dive? I did refill the coolant at the radiator side and not by the throttle body. I'm not sure if there was a certain way to go about refilling the system with coolant.

Any help and/or ideas will be greatly appreciated.

Thanks again.

 

You're right, Mazda did not use that piece of copper pipe. Someone added that.

Coolant will only come out through the weep hole in the water pump if the bearing/internal seal has failed. It shouldn't be dependent on the cap being opened either. You should see a leak from the location at all times, and it can be anywhere from a slow drip to a steady stream. If the pump is in good shape, there should be no reason for coolant to come out of this hole. You can't cause it by improperly bleeding the system.

 

Thanks for your time RR88. I'll be ordering a new water pump and follow the instructions from my Haynes manual.

 

Success. Thanks again for your help RR88. I really appreciate it.

Dave