Vibrations when running on 4 cylinders

Meradin

Member
Joined
Jul 3, 2021
Messages
7
Reaction score
6
Location
New York
Current Rides
2021 JLUR 392 / 2017 JKR
Have about 500 miles on the 392 now and was noticing some odd vibrations on the highway when cruising. It would come and go and I couldn't figure it out until I was sitting on the Fuel Economy screen. Every single time it went down to 4 cylinders, the vibrations would start. When it went back to 8, vibrations go away. Anyone else notice this. It is more of an annoyance then anything else but I think I will mention it to the dealer when it goes in for the first time.
 
Could it be bad gas? (Mine is on order, so I haven’t had the honors yet).
 
I am running 93 octane from BP in New York tri state area and have never had issues before so I I would hope that isn't the issue. We tend to have good gas here.
 
I am running 93 octane from BP in New York tri state area and have never had issues before so I I would hope that isn't the issue. We tend to have good gas here.
Oh! Your Jeep is telling you it is time to get out of NY!!! Lol (Ex NYer here, Westchester co.).
 
Have about 500 miles on the 392 now and was noticing some odd vibrations on the highway when cruising. It would come and go and I couldn't figure it out until I was sitting on the Fuel Economy screen. Every single time it went down to 4 cylinders, the vibrations would start. When it went back to 8, vibrations go away. Anyone else notice this. It is more of an annoyance then anything else but I think I will mention it to the dealer when it goes in for the first time.
you might want to look into that issue with your dealer asap. It sounds like there is a problem with the MDS system which is quite involved. the components are lifters, solenoids and programing. The solenoids are internal and basically control the oil to the lifters for the cylinders that go dormant during cruise speed. From my research, they could be the issue, or a possible lifter problem.
 
OP, my Challenger Scat Pack with the 6.4 and cylinder deactivation, also vibrated when in 4cyl mode. I think it is normal. I solved by running in sport mode which locked that feature out.
 
Is it possible to deactivate going into 4 cylinder mode? I am normally heavy footed but the vibration became rather annoying on a 2 hour drive to the mountains recently. It was noticeable even with the exhaust not in performance mode. I know you can disable it by manually shifting gears but was looking for a more permanent solution. The 392 seems more smooth and sounds better when not in 4 cylinder mode. I could care less about MPG. 😁
 
Have about 500 miles on the 392 now and was noticing some odd vibrations on the highway when cruising. It would come and go and I couldn't figure it out until I was sitting on the Fuel Economy screen. Every single time it went down to 4 cylinders, the vibrations would start. When it went back to 8, vibrations go away. Anyone else notice this. It is more of an annoyance then anything else but I think I will mention it to the dealer when it goes in for the first time.
I and another member have had the same issue. I started another thread because my original search involving vibrations yielded no results.

Any updates? I’ll be mentioning it to the dealer here soon. It’s annoying for sure!
 
Have about 500 miles on the 392 now and was noticing some odd vibrations on the highway when cruising. It would come and go and I couldn't figure it out until I was sitting on the Fuel Economy screen. Every single time it went down to 4 cylinders, the vibrations would start. When it went back to 8, vibrations go away. Anyone else notice this. It is more of an annoyance then anything else but I think I will mention it to the dealer when it goes in for the first time.
It’s the 4 cylinder vibration. Mine has had since new. Now 3000 miles and the vibe is still present
 
It’s the 4 cylinder vibration. Mine has had since new. Now 3000 miles and the vibe is still present
I looked up the MDS manual shift disable trick on YouTube. Will try that tomorrow and see if that fixes the vibration drone noise!
 
I thought someone on here confirmed the Tazer mini could disable the cylinder deactivation but I couldn’t find the post…
 
Livernois Motorsports does the MDS turn off feature which shuts down the 4 cyl mode!
 

Attachments

  • BF870771-2438-4379-A1D0-4F4B3D568953.png
    BF870771-2438-4379-A1D0-4F4B3D568953.png
    385.9 KB · Views: 126
I went on a 200 mile trip yesterday and did not notice any vibrations when running on 4 cylinders. The roads were smooth so I tried to pay close attention to any vibrations and couldn't notice any (active exhaust on and off).
 
I don't really want to disable the 4 cylinder mode as it does actually save gas. I will mention it to the deal but It might be a non issue before then because I am getting the Livernoir tune next week which might disable the function altogether. If not, I will mention it to the dealer on my 5k oil change.
 
I am getting the Livernoir tune next week
Keep us posted on the process, performance and of course, fuel economy. Are you going to have them leave the cylinder deactivation? I know they can do both, but more common for them to disable it...
(for process, I'm referring to the PCM swap, mod, unlock? Not sure how they perform it...)
 
I don't really want to disable the 4 cylinder mode as it does actually save gas. I will mention it to the deal but It might be a non issue before then because I am getting the Livernoir tune next week which might disable the function altogether. If not, I will mention it to the dealer on my 5k oil change.
Yes, please post your results after the tune. I've seen the dyno results, but it would be nice to hear how it "feels" to drive, etc.
 
Back
Top