Mazda Repair: water pump leak, coolant leak, mazda dealership

Question
QUESTION: I moved last year so I have not found a good miata repairman here yet and decided to go to the local Mazda dealership to let them swap out the plugs & wires and re-tune calibrate my '02 Miata if necessary. Right before doing this my check engine light came on so decided to go for it. 1,400 dollars later! bad secondary 02 sensor and they told me I might as well go for a Timing belt since it had 55K on it and when they got into that they found a leaky water pump and swapped the computer on warranty recall while it was in the shop. They did suggest a few other items I deemed unecessary that either I can do myself or already did to the car. Not too upset at this point but I brought the car home and in a day noticed a slight coolant leak on ground near right tire or what seemed like oil and coolant mixed. Returned and they told me bad O ring on the new water pump overnighted one and replaced it under warranty. Four days later I now have a much worse coolant leak and told them to take the car next week as long as they need until they can fix it right as I need to make a long trip soon and would prefer my engine not overheat or seize up. What else could be wrong besides a bad factory part? The first pump was leaking by 55K and now the new ones aren't sealing or something.Thoughts?

ANSWER: The secondary O2 sensor has been a common failure with the 01 to 05 models.

As for the water pump.  Extremely rare to see one leaking upon a first timing belt though not impossible they are man made.

More comment later.








---------- FOLLOW-UP ----------

QUESTION: Thanks, I thought it way too soon to be seeing a leaking pump at this point myself but since I got it back from the dealers I could smell and then see coolant. Anyway, I was wondering if there were any other known problems regarding the pump connection or another part that could be causing the leak. I like to have as much knwoledge as possible when talking to a repairman about my cars.

Answer
Be sure it was replaced with a Mazda pump.  Some places (dealers included) use aftermarket pumps which can be either rebuilt or built to a slightly different specification.

Additionally a leak could be from the heater side pipe which connects via a small manifold to the side of the pump.  It has a metal embossed gasket there.  In addition the heater pipe itself uses an simple o-ring to seal the tube to this manifold that delivers coolant to the heater.

Beyond that, a thermostat not properly seated can cause a leak at the thermostat housing, or it could be hose related, several are disconnected and re-fitted as part of the service.  A damaged bypass hose or main flow hose (3 in total, two lower one upper).

If you want to get a second opinion on the coolant leak, take it to another shop and ask to have a pressure test done on the system to locate the leak.  This will tell you in advance of going to the dealer where the fault is and could prove to be a means of checking their integrity.  

In short the only thing a 55k Miata should have needed is a timing belt which in hind sight could have gone another 8-10k without an issue.  Bearer of bad news, yeah shot in the foot, yeah.  Sorry for your experience.  

On a plus note a Miata is good for over 300k and 20+ years when properly maintained.  When you get past this fiasco drop us a line before you get sucked into another vortex.