2018 MX-13 T880 oil pressure and temperature issue
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Hello all, first post, not a trucker rather a Cessna driver and aircraft mechanic.
I was asked by a very dear friend of mine to assist in searching for and checking out a truck for his new O/O operation and long story short... after purchasing the truck, a 2015 Kenworth T660 almost 600,000 miles with the Paccar MX13 EPA13 engine, on his way to his home base 2 hours away, it was clear that he had a high oil temperature issue. It blew my mind because all of the indications show that his engine is barely breaking in (almost no crankcase pressure at high idle, clean breather tube... compared to the Volvo he was also looking at where the breather was almost dripping oil at 400k+ miles) and his coolant temp was not passing 180* on the road home.
The reason I am tagging onto this post is my way of saying thanks to many of you on this board who contributed in helping me help my friend resolve his issue and I would like to share what I learnt with y'all.
After searching all sources of information concerning this issue, which are numerous, I was able to get the flow chart of the Oil Module on the right side of the engine and it is clear that ANY oil temperature/pressure issue can be pinpointed to that module. Very nice piece of technology.
First, the oil is picked up from the oil pan and is pumped directly to the module and goes to the top of the oil thermostat housing. From there it goes to 3 different routes:
-one branch goes to the Main oil filter which sends clean-cool oil to the engine to lubricate/cool.
-another branch goes to the oil cooler although when the oil is cold, most of the oil goes directly to the Main Oil Filter and little goes through the cooler. From the oil cooler it goes to the Main Oil Filter to deliver cool-clean oil to the engine to lubricate/cool. When the oil starts to get hot, the thermostat closes the direct path to the Main oil Filter sending all the oil through the oil cooler to maintain the oil temperature in range.
-third branch which is the excess oil goes to the secondary rotating oil filter, uncooled then back directly to the oil pan.
What can go wrong and what did my friend end up doing, after reading all the horror stories of the dealer's service departments and mechanics and discouraged Paccar Operators? He went on a dyno to put a load on the engine (unfortunately KW dealer did not have dyno), he confirmed that the oil temperature would have passed red line and derated had he taken a load on the road. He went to the KW dealer's service department who were told of the issue to troubleshoot. After having put the truck on their Davie4, they said that they could not say what was wrong but the truck would have to come back to examine the oil module more closely the next day. My friend paid the bill, went home and took all the mechanical knowledge he could muster from wrenching from an early age and decided to do the job himself. After reading all the threads on this site and on others, it became clear to me that after a certain amount of miles, the oil module needs to be restored. The issues are:
-First the thermostat which can be checked by putting in a pan of boiling water with a thermometer. It should start activating at 215*
-Oil cooler which gets cruddy from use on the oil side and on the coolant side. If the truck showed symptoms of a cooler leak (oil in the coolant radiator), "stop leak" is sometimes used to cure the leak but ends up clogging up the coolant passages in the cooler impeding heat transfer (his cooler definitely had a restricted passage on the coolant side).
-last but absolutely not least (least understood and most critical) is what is referred to on these threads as the rotating oil filter bottom bearing. Actually the bottom bearing is also a rotary seal which makes sure ALL the oil coming through this passage goes THROUGH the filter, thus regulating oil flow through the module. IF that seal is not sealing, oil flows through the bottom of the filter WITHOUT going through the secondary filter which has the consequence of dropping the oil flow trough the Main Oil Filter/Oil Cooler arrangement, thus less oil cooling to the engine and more uncooled oil going directly back to the oil pan and the heating cycle begins. One reason for a leaking seal is the use of multiple filter brands at PM time. As I was informed on one of these threads in my research, the Paccar filters spin in one direction. To bypass the patent on those filters, the other brands turn in the opposite direction. My friend found an off brand filter which had the pipe going through the seal deformed (absolutely was a source of leak). Rubbing mechanical assemblies like to maintain their same position to develop a wear pattern. If you change rotations a couple of times on that seal, that is enough to disturb the wear pattern and make that rotary seal leak which affects the oil temperature, even though the drop in pressure on the system is minimal.
My friend replaced his thermostat (old one was still working but he figured if the first one gave 590k miles, this one will last the next 590), his oil cooler, his bottom rotary oil filter bearing and the oil filters with Paccar filters. He also replaced the coolant filter which he found corroded and questionable.
Result is that the system is operating IAW (in accordance with) Paccar Standards:
- On startup, Oil and Coolant temperatures start rising together. The coolant temp stops at 180* and the oil gradually continues to 210* (without a load). Once the oil reaches 215*, the coolant temperature starts to climb a few degrees and the oil temperature drops below 215* (very difficult to reach 215 without a load). Before the repair, there was no relations between the oil temp and the coolant temp, indicating that there was no heat exchange happening at the cooler when the oil got hot. Now my friend is ready for the road... waiting on a few more red tape items to get his Authority and he's out on the road, confident that his engine is working as it should and looking forward to the next 600k miles. Nice truck!
One: I understand why mechanics don't like to work on these engines and rag on them. You need a different set of tools (metric) otherwise you are going to get yourself in a lot of hurt if you try to work with your US wrenches.
Two: For those users and operators of a Paccar MX13 engine, apart from the lemons (which all brands have), this engine requires to be operated, not driven. I think that operating an MX13 truck draws the line between a driver and an operator or if you prefer, that's what separates the men from the boys (I have not read one lady/operator complaining of the Paccar engine). I'd take a Paccar any day over a Cummins for that model truck.
Last note: if any of you feel I can help you understand your Paccar, please feel free to ask. I will do my best to troubleshoot from far away (I'm in Haiti), just like I did for my friend. As long as your questions don't go into the after treatment system. Sorry, my Cessnas don't have after treatment.
...icing on the cake... Arrow of Cincinnati ended up footing the bill since they were advised immediately upon taking possession of the truck, at which time my friend was told to get an estimate for any necessary repair.
My buddy did the error of not keeping them in the loop after the Dealership told him to come back the next day for diagnostics after spending 2 hours on the Davie4 (that's why he was there in the first place). He just did not feel comfortable with those horror stories on posts concerning "high oil temperature on Paccar engines" and felt more comfortable understanding, diagnosing and fixing his lubrication system problem himself. He now knows exactly what he has under the hood.
The guys at Arrow were great. Since my friend had documented his repair, starting with the Dyno test where the engine derated a bit above 250*, both the salesman (Jamie) and the manager were able to go at bat for him and got him reimbursed for the repair even though this was not covered under the warranty. I had heard of these guys but now they just proved with actions that they DO CARE about the little guys... the first time O/O... their CLIENTS. I highly recommend them for those in search of a used truck. Ask for Jamie (knowledgeable, has his CDL and has been on both sides of the aisle plus keeps his word).
Again, respect for all of you on the road behind the wheel and my hat's off for the Top Notch Techs keeping them SAFE on the yellow brick road.
KEEP ON TRUCKIN' GUYS AND GALS.
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