X15 Random Coolant Loss

[Rawze]

(05-14-2023 )BobbyTTour Wrote:  The truck is still 100% compliant. The shop pressure tested the system and did find two very minor leaks which were resolved, but didn’t pull the pan. Oil is not cloudy nor is the level rising.

2019 Peterbilt 579
330 original miles
525/1850
18spd
3.25 rears
LP22.5

First of all ... The statement "oil is not cloudy or rising" means absolutely nothing at all and is no indication of anything. A failing head gasket typically does not do this to the oil... though it might show some small signs of coolant intrusion on an oil sample from a lab... and sometimes not even then.


Next.. is that fact that it is 525hp,1850trq combined with horrible 3.25 rears in it. - That is absolutely a terrible setup that will definitely cause that engine to suffer a shortened lifespan, eventually blowing a head gasket (dropped liner) due to it lugging its whole damn life below 1500rpm.

- That spec is set up for pure engine torture like that, I would not give that engine more than about 500k miles before an inframe as it is, set up like that, ... so it certainly would not surprise me if it blew out at 330k miles, especially if someone is driving it hard (foot to the floor all the time + too lazy to down shift on hills half the time).

You could not give me that truck ... it has taller rears than my S.U.V. ... ready to lug the engine its whole life into an agonizing death. I would have had to change out the rears to something made for hauling freight, the day it was purchased.


If it is not simply some weak hoses/coolant leaks .. which you say, were fixed.. then the next step is to drop the pan and do what I said above, to find it.