Or the liners or the seals or the coppers in the heads or the oil cooler etc. Lots of places for coolant to get into on a big diesel
Yes, this is a Mack engine. Because this was formerly a concrete mixer it got tremendous amounts of hours put on it. That's why it has 26,000 hours with only 262k miles. A head gasket is a possibility(bear in mind this is an inline 6 but has 2 cylinder heads) but on these engines liners are more likely. I will do diagnostics as necessary before totally tearing it down though. The liners are surrounded by coolant and the sealant degrades over time and thousands of hours.For all those folks on here that deny what a UOA can show about engine issues show them this.
Anyways, it appears this was confirmation from the last test that showed elevated Potassium/Sodium. Pardon my ignorance but Mack built this engine? Looks like you got over 250k out of this engine so a rebuild may get you another xxx miles? Is the engine itself ok just needs new head gaskets? Sorry about my questions but I'm a sponge by nature. Thanks!
I will be pulling the pan to pressurize the cooling system however on these engines with the amount of hours it has, liner sealant failing is way more common. These have wet sleeves(surrounded by coolant) but don't use liner seals. You seal the sleeves into the block with Mack Silastic. Head gaskets are rarely a problem on these.
Great info! Another aspect is that if it was the oil cooler there would be coolant in the antifreeze so perhaps there might be a way to test the antifreeze for that? Outside of a visual inspection? I don't know if a test lab would or could do that. 2 heads on the inline..interesting! 26k is a lot of hours for sure. Hope you get it narrowed down & put it back to work.
Caterpillar did that too. Cummins used 3 heads.
Wow, That is wild. I don't know a whole lot about these HD engines to be honest. All I know is that Mack has really started to push more into the OTR segment over the last few years.
@Creekside truck was a concrete truck in its former life. I’m guessing it averaged no where near 42mph.
Re-read the post. It compares the engine hours in a construction application to the same number of hours on a highway tractor. The application is different but the run time on the engine is comparable.
But 25 mph avg is probably a better guess to compute mileage. Based on 25 mph, since it's a concrete truck & not an OTR truck, it would be around 650,000 miles equivalent not 1 mill.
T2070 is what mine has also. Mine is a T2070B with multispeed reverse meaning you select reverse via an air selector switch on the shift lever. I can shift 1-5 speeds in reverse same as you can going forward.
usually with an oil cooler issue, the oil tends to go in the cooling system, simply because it is under higher pressure than the coolant.. doesn't mean the stuff wont drip back into the sump if sitting, but will be at a slower rate.
