Hi there, My 2015 Mazda CX5 2.2DE Akera AWD Auto was and is out of warranty and had a new engine fitted 2 years ago by a Mazda Dealership in South Africa and has done less than 6500 miles. The vehicle had a water leak late last year and the dealer said that they only replaced the engine block, cylinder head, injectors, turbo's after the engine failed following another Mazda dealers negligence. Their feedback is that the water pipes and water housing were not quoted/replaced on the original engine replacement as there was no visible defects on them and tested fine after the engine replacement in late 2019 the water leak that was attended to in late 2020 was due to a hairline crack along the water housing and that this crack could have developed overtime and is impossible to ascertain when or how the crack occurred. The vehicle was returned to them in March 2021 with no water in the radiator and check on vehicle smoking. After re-filling the cooling system and getting the vehicle up to operating temperature frothing/bubbles the coolant was observed and according to the dealer this could mean two things, either a blown Cylinder Head Gasket or the EGR Cooler could be leaking. The dealer requested authorisation to remove and pressure test the EGR Cooler as that would be the 1st place to start. The EGR Cooler did initially test ok by their Vender but the dealer wanted to do more testing to 100% eliminate the EGR Cooler, hence requested more time to do further testing. As explained we by-passed the EGR Cooler and swapped out another EGR Cooler and at both times the vehicle tested fine(no frothing/bubbles). For one final test we re-fitted your EGR Cooler and again the frothing/bubbles of your coolant could be observed and then based on this according to them, 100% confirmed that the EGR Cooler was indeed leaking and needed replacing. After the fitment of the new EGR Cooler the vehicle tested fine on idle and stopped smoking and only after the road test did the coolant push through the expansion bottle illustrating that not only was the EGR Cooler leaking but that there was now clear evidence that the Cylinder Head Gasket was also leaking and would need to be stripped to establish what the extent of the damage is. My argument is why was the water pipes not replaced when the engine was replaced and secondly how do you diagnose something and then suspect its that and them replace it and then the vehicle provides the same symptoms. As mentioned this engine was fitted in late 2019 and the vehicle drove less than 6500 miles following lockdown. I have received the quote to replace the EGR which in my opinion was never the issue and then a quote to strip and assess and fit new gasket or possibly a new cylinder head and worst case another engine. Any advice? I’m trying to establish what is Mazda’s guarantee on fitment of a new engine and also whether if this occurred on a vehicle which was under warranty, would Mazda replace all water hoses to avoid a pipe perishing so quickly on a Newley installed engine.