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EGR Cooler?
So one of my Aqua Hot customers broke down not a (Prevost) on his way to meet me for his service on his Aqua Hot, But anyway his Red check light low coolant light came on, so he pulled over and added 4 gallons of coolant and took off a few miles later lights came back on, so he pulled over in Templeton right around the corner from me. I drove over there expecting to see a broken hose, he was in a 2009 Alpine with a Cummings it looks like new. So no sign of any leak just signs under over flow hose, 4 gallons is a lot of antifreeze loss, so we topped off fluid 2.5 gallons, and he was going to limp down the road to park and following him it blew out white smoke or steam bad. I had checked oil it looked good not white. So my neighbor is a Cummings dealer and he said leaky head gasket is not common on that motor But the EGR cooler is more likely to be it. So a EGR filter cooler he said exhaust goes through the cooler to cool exhaust and when cooler lets go all the antifreeze blows out the exhaust like I see. What the heck kind of a emission thing is that, Antifreeze in your exhaust system? So he is in my neighbors shop parking lot waiting for repair.
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6 Replies
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I’m not sure an EGR intercooler leak will push coolant directly out the exhaust.
It is true exhaust from the engine is routed through the intercooler but from there it goes directly into the intake manifold where it is introduced to the cylinders.
If it truly went out the exhaust that would be far better than being ingested by the engine. I hope the engine was not damaged because it sounds like a large amount of coolant was carried into the cylinders.
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Jon is right usually the cooler leaks into the manifold and into the cylinders thus the white smoke and sometimes hydro locking the engine and or bent valves, I have some experience with this. I have worked on many modern diesels with these systems in places they are terrible many failures and most modern diesels won’t make it past 500k with out an inframe because of all the emissions pumping into the motor. Best thing your customer can do is remove all the emissions that’s the Egr, dpf, def, scr filter it’s a Cummins so there is programming to eliminate those systems out there,or trade it in for a vehicle with no emissions on it.
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it was EGR after engine it cools exhaust after engine, I talked to buddy at shop and antifreeze blew out exhaust after engine, He said it’s not a inner cooler
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Anybody have any experience with by-passing the EGR? I heard it will improve fuel economy as well as eliminate future problems. Also heard some shops will not work on the engine if this has been done. Thanks
2000 Featherlite H3-45
2024 Jeep Grand Cherokee
Leesburg, FL -
Your coach will not have and EGR engine. I am confident of the following information which does apply to Detroit engines equipped with an EGR.
The EGR engines have the ability to pass some exhaust gas through a cooler prior to it entering the intake manifold. The purpose of the cooler is to drop the temperature of the exhaust gases which can easily reach 1100 degrees to a temperature much lower. The exhaust gases are mixed with intake air to lower oxides of nitrogen.
When the EGR is passing exhaust into the engine the the turbo boost is increased from a maximum of about 30 PSI to about 50 PSI. That will not show on a dashboard gauge, but with a reader attached to the coach it can be seen. When the EGR is passing exhaust it also is enriching the mixture to provide no loss of power.
At one time there were unsubstantiated reports of EGR equipped Series 60 engines having early problems with the #6 cylinder.
There are ways to defeat the EGR. One is to install a device called Ugly Fix. If the default programming of the DDEC is to not allow EGR operation at altitudes over about 11,000 feet above sea level the Ugly Fix will make the engine believe it is operating above 11,000 feet and the EGR will not work.
Not all coaches are programmed to disable the coach above 11,000 feet so if that is the case the program has to be modified. An alternative is to program the parameters of EGR operation. The EGR is programmed to operate within a certain RPM range. It can be reprogrammed to operate within any RPM range, such as a range above the engine RPM limits.
As to mileage the likely improvement in mileage is going to be in the range of .5 MPG or about 10%. There is a side benefit as well. With a functioning EGR the oil gets black almost immediately after an oil change. Without the EGR the oil will retain its clear golden color for as long as 2500 miles.
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Spot on
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