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vett747 · 01-10-2020, 09:20 PM

I have a Cummins ISL 8.9 in a SportChassis and have owned it since new. This is our second year of ownership and the truck has over 50,000 miles on it currently. However, I've had repeated EGR cooler failures. The first one took place last year and the truck had around 25,000 miles. Freightliner replaced cooler and cleaned out the EGR value. They were completely filled with soot. This last month, we again had the EGR cooler fail and the truck had 50,000 miles on it. We also went to a different Freightliner than the one before. From the day we picked it up, we put a 10 minute idle shut-off. So, we have never allowed the truck to idle for extended periods of time. So, my question is if anyone else with a Cummins ISL 8.9 had problems with their EGR cooler? If this happens again, my plan is to go to a Cummins shop and see what they have to say.

Wild Card · 01-11-2020, 05:17 PM

There were early design egr cooler problems, but nothing new that I have heard of especially not 2014 era. This was water side rupture dumping coolant into engine

How is it failing? Rupture on water side or just full of soot?

If it's clogged with soot most likely it's an engine performance issue. I would involve Cummins about the issue for sure.

vett747 · 01-11-2020, 06:56 PM

When the first failure happened, they put the upgraded cooler in. Our truck is originally a 2014 and we brought it as new-old-stock. So, we have the new style cooler, but still has happened again. Both times the cooler was completely filled with soot and had to be cleaned and replace. This last time, Freightliner stated that it was leaking coolant.

Wild Card · 01-12-2020, 04:37 PM

What's your idle time? I know you stated that you put a 10 min shut down control, but that 10 min here and there adds up quick. Any time it has to idle you should bump it to high idle.

Any cold non complete combustion crates soot, these engines use alot of egr during idle. Soot clogs cooler creating hot spots, hot spots crack the brazed welds in the cooler thus it starts leaking coolant into the egr intake side.

I know the 1st cooler design wasn't vented properly and supposedly could create an air pocked on the cooler side which would overheat and crack. Are you sure you had an updated cooler installed? You can go to Bullet Proof Diesel and see what the updated cooler looks like. It requires re piping the water connections. The factory Cummins updated cooler looks the same and requires the same piping mods.

Did they check your egr valve and controlling sensors, how about your intake grid heater? That much soot in that short amount of time could plug your intake.

Cummins will pull your engine data and compare idle time, so should Freight Shaker.

I am interested in this topic and I thought these issues were a thing of the past, still can cause issues but egr in diesels has been around for 18yrs now. I have and 08 ISL and I have searched this topic specifically as EGR is a bad thing if things aren't right and even then it's not ideal. The little I have learned is the engine temp must be up and combustion pressures must be up for a complete burn with minimal soot produced.