lagerstout
Senior Member
- Joined
- May 15, 2015
- Posts
- 168
- Reaction score
- 79
- Location
- Somerdale, NJ
- Ram Year
- 2017
- Engine
- HEMI 5.7
When I ran 5w30 I only saw slightly higher Oklahoma temps.
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Was this on the RAM?I wanted puro to work because it was cheaper, had to take one off my engine, so I gave up on them. Maybe that filter is just fine, but I'm staying with my RP.
Anybody know what code will it will actually set? I mean is there even a code for wrong oil viscosity?
My plan & thoughts exactlyThe code is P1521. At least is used to be back when I worked at the dealership. Never saw a Hemi engine with that particular stand alone fault code. The 5w/30 RL is still purring along in mine with NO fault code! The 5w/30 PUP from Gina will be going in this spring. My only concern will be the return of the noisy knock/tap I had before using the RL 5w/30. As far as setting a code I'm not worried at all about that.
Ha well guess that answers that...Yes, the only time I had any tick whatsoever with redline in, was blue puro synthetic. I had no issues with yellow Puro, but if course that is their paper. I put RP back on, the tick was gone immediately. It seamed like it was choking off the engine, weird.
So this code would set with other codes?The code is P1521. At least is used to be back when I worked at the dealership. Never saw a Hemi engine with that particular stand alone fault code. The 5w/30 RL is still purring along in mine with NO fault code! The 5w/30 PUP from Gina will be going in this spring. My only concern will be the return of the noisy knock/tap I had before using the RL 5w/30. As far as setting a code I'm not worried at all about that.
So this code would set with other codes?
RT: Will these codes be more prevalent to show up during cold startup (when the oil is possibly @ it's thickest viscosity)? OR when the MDS system first tries to engage & encounters a oil psi issue?
We all know as an oil reaches operating temp the viscosity becomes thinner compared to cold startup.
I have read many BS opinions/guessing on this scenario!
I guess what i'm trying to figure out is---->if the MDS system is going to malfunction (due to a so called Thicker Viscosity of oil) at what point in time would this system more than likely encounter issues?
This is the post I've been looking for!!Not sure how to link an old thread onto here, but a thread started by FLRAM on 4-12-14 has a great explanation of the requirements the pcm needs before it will allow mds to kick in or throw a code.
Here's a quote in that thread by Ramzaq....
When MDS engages your rpm's do not drop that is the transmission going into one of its overdrives, also the difference in sound when the rpms drop is the same thing. Gear change different exhaust note.
With that being said, when the truck is actually in MDS mode the exhaust note will change which is more noticable at the lower speeds, something of a 'fitty' sound.
Also check around on this forum or do a search. You will find plenty of discussion on this topic.
Matter of fact this is one of the most consistent topics discussed going back probably to 2006 on any (Dodge) Ram forum.
I posted this elsewhere but should answer many of your questions.
Some say they can tell by the change in the exhaust note that it is active, others say they don't hear a difference.
The "Fuel Saver" indication means you are driving in a fuel efficient manner. The MDS mode may or may not be active while in FS mode.
The only true way to tell is to hook up an external indication to one of the cylinders that goes inactive. One individual hooked up an LED indicator and ran it to up to his dash. He now had a light that told him when it was active or not.
"From AutoInc.online:
How Chrysler's Multiple Displacement System Works
Posted 10/12/2009
By Greg Montero
In 2005, the Multiple Displacement System (MDS) version of the 5.7L HEMI engine was introduced on the Chrysler 300C and Dodge Magnum. This engine can deactivate four of the eight cylinders, and operate as a 4-cylinder engine during periods of low load, improving fuel economy and emissions. The MDS provides the 5.7L engine the fuel economy of a V6 while maintaining the performance of a V8. The fuel economy improvement is estimated to be up to 20 percent, depending on driving conditions. The MDS operation, invisible to the driver, is fully integrated into the fuel injection system.
"In 2005, the Multiple Displacement System (MDS) version of the 5.7L HEMI engine was introduced on the Chrysler 300C and Dodge Magnum. This engine can deactivate four of the eight cylinders, and operate as a 4-cylinder engine during periods of low load, improving fuel economy and emissions.”
When the MDS engine switches to 4-cylinder mode, the powertrain control module (PCM) controls solenoids that manage special "dual mode" lifters, allowing the intake and exhaust valves to remain closed on cylinders 1, 4, 6 and 7. There is one solenoid for each cylinder (two lifters). The PCM also deactivates the fuel injectors for these cylinders when in the 4-cylinder mode.
When the MDS solenoids are in the "off" state (8-cylinder mode), they supply oil pressure of approximately 3 psi to the lifter bores. This lifter oil keeps the bores lubricated and prevents air from entering the system. When the solenoids are activated, oil pressure of 16 psi or greater is supplied to the lifters and the engine enters the 4-cylinder mode.
When the special lifters are supplied high oil pressure by the solenoid, pins inside the lifter move inward. This unlocks the outer portion of the lifter and allows it to move independently from the center portion of the lifter. The camshaft can move the outer portion of the lifter without transferring motion to the inner portion of the lifter.
8-cylinder mode: Solenoids are in the "off" state (de-energized). Minimal oil pressure is applied to the special lifter. They are working normally in this mode.
4-cylinder mode: Solenoids are in the "on" state (energized). High oil pressure is applied to the special lifters and the lifters become inactive and essentially the four pistons are along for the ride. Both valves are closed.
The PCM will activate the 4-cylinder mode when the following enabling conditions are met:
Low engine load
1200 to 3000 rpm
Vehicle speed between 12 mph and 90 mph
Battery voltage from 9 volts to 15 volts
Oil pressure from 15 psi to 147 psi
Oil temperature greater than 120 F
Engine coolant temperature from 158 to 248 F
Ambient temperature from 14 F to 248 F
No throttle position sensor or MDS faults
The PCM deactivates solenoids one cylinder at a time in the firing order. If the system is "on" for long periods of time, such as a long flat road with no stopping, the system will return to the 8-cylinder mode approximately every six minutes to maintain engine temperature. The PCM will also unlock the torque converter before the transition, to minimize the effect on driveability.
The oil temperature sensor used for this system is a two-wire sensor, negative temperature coefficient, like the sensors for engine coolant temperature or intake air temperature (IAT). The PCM uses this input - along with oil pressure, load and rpm - to calculate oil viscosity and flow rate. This information is critical to MDS operation.
It's important to know this engine uses 5W-20 engine oil. If the wrong oil is used, fault code P1521 can be set, and the vehicle may show symptoms of a shudder - similar to a torque converter shudder - when the MDS system is activated and deactivated. Other symptoms may include MDS performance codes or engine misfire codes.
Before spending a lot of time with these codes, use the vehicle service history to find out what type of oil is in the engine. Because this is not always possible, the next best thing is to replace the oil (and filter) with 5W-20. This may have to be done twice to fully restore the system back to normal. Oil sludging, restricted oil passages or lifter contamination can also cause problems with this system.
Quick facts:
Each MDS solenoid has about 12 ohms of resistance. When the solenoid is activated by applying 12 volts to it, an audible "click" can be heard from under the intake manifold. This test can be done with a jumper wire or by using the actuator test mode (ATM) mode of a compatible scan tool.
If the solenoid is mechanically stuck in the "on" position, the result will be one dead cylinder.
Hopefully, this information will be helpful if one of these systems shows up in your shop."
Years a go I had read an article by Chrysler saying that the MDS will not become active till you are traveling over 35 mph and will also drop out when you are around that range also.