today i wanted to clean my EGR.

but when i disconnect below hose (picture) , coolant water splash out from there enter image description here

is it okay this? why we have water in EGR?

  • Which car is the EGR valve off? Where does the pipe go to?
    – HandyHowie
    Oct 16, 2018 at 10:56
  • The pipe go to head cylender. I will check it for sure. (I must remove the battery box)
    – Mostafa
    Oct 16, 2018 at 21:57
  • Mazda 3 - 2008 2.0
    – Mostafa
    Oct 16, 2018 at 22:06

1 Answer 1


No, it is certainly not okay, but I doubt it's coolant. It's probably condensation...


HandyHowie and the OP (Mostafa) are indeed correct. Now that I know what vehicle we are speaking of, I went to AllData and found this:

2008 Mazda 3 2.0 EGR

It is coolant, and for exactly the reason Howie suggested. EGR reduces combustion temperature with a "cool" non-combustible gas (exhaust), which leads to lower NOX emissions as well as the ability to increase timing advance without damage. In some vehicles, ostensibly this exhaust gas is cooled even further with engine coolant.

I done learnt something.

So, the good news is that it is exactly as it should be, and there may be some residual coolant if the hose is removed.


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