2017 CX-9 Overheating Issue

[tonyfigueroa]

I have a 2017 Signature AWD CX-9 and it began over hey. Took it to the dealer for diagnosis and after 7 hours, without locating a leak or damaged head gasket, and a consultation with Mazda or North America, it was determined that a water pump was the culprit. That “fox” worked for one month, now the overheating issue has resurfaced with a “sloshing” sound behind the dashboard. Any thoughts before I take the car back to the dealer for another diagnosis?

 

[yrwei52]

How many miles does it have on your 2017 Signature AWD CX-9? When you said “overheating”, what is the symptom? Was there overheating warning on dash and the coolant temp gauge went to the red zone? Have you ever checked the engine coolant level when the engine is cold?

After a month with a new water pump the overheating problem came back? I’d say it’s very likely you have a cracked cylinder head、bad exhaust gasket、or bad head gasket with a slow coolant leak. When coolant level became very low due to the slow leak, you have overheating problem.

Water pump itself can never be the cause of overheating problem unless the Impeller has physical damage (very rare except it’s made of plastic) or the bearing and seal has worn causing the coolant leak. These problems on water pump are very obvious and the tech didn’t need to consult the MNAO corporate hotline to figure those out!

The 0sloshing” sound behind the dashboard could be the coolant is “boiling”, or too much air in the cooling system.