EGR cooler leaks again.

[amailloux]

It seems like every 6.4 that rolls in has coolant crust on the gasket between the coolers and on the erg temp sensor b. These fleets want to be proactive, but do you guys replace coolers for just having coolant crust on the gasket and temp sensor. I for sure don't want to be called out for replacing parts that dont need replaced, but again, I don't want a bent rod from a cooler failure after I inspect the vehicle and give it an ok. Just want to know what you guys consider failed for the horizontal cooler.

 

Thanks a lot.

Alan

[Matt Saunoras]

That's a tough call. The temp sensor is a good indication and it's what I go for first. I have quickly pulled EGRT2 temp sensors out of a hot engine to confirm that the carbon is wet with moisture and pretty quickly lightens up as it dries out. It also stands to reason if a vehicle has coolant loss, no external leaks (we know where to look by now), no elevated oil level or intermix, then the coolant has to be going somewhere.

 

Another thing I am noticing is a bright shiny blotch on the cooler tubes that seem to indicate coolant has washed the carbon from the core. similar to when you find a suspicious clean spot on a 6.0 cooler. You've gotta watch just looking at staining on the outside of the cooler. There are many other external leaks that can leave stains on the cooler body. The rad hoses and even coolant tube between the coolers can leave dried residue around.

 

If I think about it tomorrow I'll snap a pic of a horz cooler I just did that has spots washed clean on the core. cust complained of coolant loss and that was it

[lmorris]

You can always loosen the connection between the 2 coolers and pressure up the system when its hot to see if you get any coolant leaking out. Hotline told me to run the engine at around 1500 RPM with the EGR valve commanded open to get the coolers good and hot first.