T6 cfca overheating issues

[kampi1]

Hi all, I am currently working on a cfca engine that is having overheating issues. Issue only arises down the highway when you start to push it. It has recently had a new water pump and thermostat before it landed into my hands. I have tested the cooling fan operation, pressure tested the cooling system, tested cooling system for combustion gas with out any success. I am suspecting it has a cracked head regardless of the sniff test of cooling system results as these are indicative only but in starting removal of cylinder head noticed it has a egr coolant pump. In further research I have learnt that these can also contribute to overheating issues. Has anybody struck this before, does anybody know if these pumps run all the time during operation or is it temperature based? Its runs on a bench test but does make a bit of noise (chatter) from time to time like the bushings are wearing out. Any help very much appreciated

 

[Big Al]

Have you scanned it for a fault code? The pump is PWM controlled if i`m correct and doesn`t run all the time.

 

[Loz]

Is it losing cooling fluid? If so how much (You didn't say)

 

[DXX]

There are known issues with the CFCA EGR unit aside from the cooler corroding and putting alum’ oxide debris into the induction.
The EGR cooler corrosion can also perforate the cooling circuit within the cooler resulting in coolant loss into the engine, in theory it is possible for exhaust gas to enter the cooling system.
The cooling system requires vacuum filling as does not self bleed well.