A little history first. I am a fleet manager for a company in central Florida. We have a 2015 Ram 2500 4x4 automatic that had a reman Mopar 6.4 installed about 20k miles ago. This was done a few years ago before i started working for the company. I do not know the story behind the previous engines failure and was not involved in the install of the reman engine. The truck has about 135k on it. I received a call Friday from the employee driving the truck that he was stuck in an intersection and the truck would not move. I sent a tech to the scene because the local police department was there directing traffic around him and he was within a few miles of the shop. When he got there the truck was shut off and now wouldn’t crank. There was coolant all over the right side of the engine bay but the coolant was full and so was the oil. I had it towed back to the shop and upon further inspection we found that the engine is seized up solid. scanned for codes and there is 11 transmission codes that are related to a transmission that was slipping. Everything from gear ratio to pressure codes. There was no engine codes. We got the truck on the lift and pulled the serp belt and starter hoping for the answer to the engine was simple. No such luck. Drained the engine oil and its black but was full and did not see any signs of metal that would lead you to a mechanical failure. I talked with the driver and he proceeded to tell me in broken English how he kept trying to get the truck to move. With giving it gas. Not sure how long he tried that before we arrived or if the engine stalled or was shut off. I inspected the mopar installed overheat tab on the left rear head freeze plug and its pink. That now tells me that the engine got to 255 Deg.
Now the question, has anyone dealt with a 6.4 that overheated and locked up. Has anyone seen a transmission lock up and keep the engine from turning at all? If this driver ran this truck to a point that after the transmission failed he took out the engine to is a very bad day.
I do know what types of damage overheating an engine to the point of seizing are for the everyday engine but is there anything about the 6.4 that is more specific to it.
Of coarse the owner is hoping that since they just paid crazy money to buy the reman from Chrysler during covid that it is Repairable If it’s the motor locked up Also. As the fleet manager i really don't want to pull the motor and transmission and tear it apart if someone has been there and can give me what they found a 6.4 overheat sieze destroys. Used engines are a fortune with little if any warranty, reman with the strike will most likely be hard to find and cost some big bucks then ad a transmission to the mix it turns into a WOW. New trucks a through the roof and the driver really doesn’t deserve a new truck the way he toke care of this one. The best case is the transmission is keeping the engine from turning but I have never seen it.
Thanks for spending the time to read this long post and any ideas would be appreciated.
Since I was and am a child of the General going way back, (GM) I'll share this with you about GM's tech on a current vehicle and how it WILL surprise folks:
First off, these technical issues are likely shared across brands, in that the automotive world has become "Globalized".
The 8L90 automatic transmission used in the Silverado/Sierra/ Escalades, et. al. is a very different trans.
This unit has no bands, has no accumulators, and has a remote pressure pump which is incorporated into the valve body and chain driven from torque converter.
This tranny has ACL pressure directed to ALL of the clutch packs at 8PSI upon initial start up. This purges the air from the hydraulics to ensure smooth, trouble-free initial operation when one uses the vehicle after being parked overnight.
Moreover, the shift solenoids are controlled during both clutch application and deactivation to make both upshifts and downshifts seamless.
In the event of a start-stop system, the trans has a powerful accumulator which keeps trans pressures up to operating levels for a seamless transition once the vehicle restarts.
The ATF is of a specific and VERY expensive type; and the fluid service procedure rivals an appendectomy!
I'd think that RAM and others are in the same league.
