Just took my mechanic my '01 122k MAX SE to replace the alternator and had an interesting discussion with him about the problem with leaky heads in 01 - 03 maximas, leading to coolant leaks that get into the combustion chamber and throw O2 sensors and CAT converters out eventually. He says this has been admitted by Nissan, and they have new dye casts for the heads now for those vehicle years that don't have that problem. I guess the metal had little holes in it.

He explained this is why the CEL light is such a nuissance in those models, why they sometime miss and sputter in the morning upon first ignition, etc.

Anyone agree?

 

Not that I've heard, plus I'm not even sure the heads on the 5.5 gens are the same as the 5th gens.

 

Sounds made up

 

That's happens when you don't change your coolant annually or even once every two years! The aluminium will corrode heavily and deeply if the coolant system maintenance is neglected so this is a word to the wise...Just do it!