Truck shaking at idle

[stroogs]

I've seen a few other threads on this but I've never found any resolution so I figured I'd ask and see if anyone else has similar experiences. I recently purchased a 2020 Ram 1500 big horn with the 5.7 hemi. The truck shakes very noticeably when at red lights or in park. I'm not new to trucks and I've owned many v8s that let vibrations through, they're big motors after all, but this is more erratic and feels like a misfire, however, the idle is rock solid at 500 with no variation. I had the dealer look at it and they said "they just do that" but I'm not entirely sold as I drove a few others and don't remember noticing it. With the hood up and the engine running I can see the whole motor shake a bit when it has it's "stutters". Would exhaust manifold issues (bolts or crack) affect back pressure enough to cause this or is it more likely a vacuum/throttle body issue?

 

[theblet]

Mine does this sometimes. I’m thinking it may be due to running 87 octane, but I haven’t tried 89 yet. Runs great when on the throttle. Another thought is to clean the throttle body.

 

[Scram1500]

Does it do it in park or neutral?

 

[theblet]

I notice it more in neutral.

Not sure what the camshaft specs are, but maybe there’s some overlap in the valve events which cause lope? Factory cams are usually pretty mild, just thinking out loud.

 

[Darksteel165]

Is it really 500 rpm at idle? Seems a little bit low. Maybe it's struggling to keep running.

Try a tank of 91-93 and see if it goes away, maybe throw a bottle of HEAT in too.

 

[User_3336]

in a Previous model year, mine short of shook a little upon startup for about 2-3 minutes.

Some were saying do a idle-relearn.

My 23 does not exhibit this annoyance.

Idle is about 750rpm.

 

[kdoublep]

I've never experienced this either. 500 is low.

 

[stroogs]

My idle is 500, and it only shakes when it's that low. Today I went to a Ram dealer and ran a few 2020 and 2021s. They all shook in a very similar way. Mine is a bit more pronounced, but it is the same thing. I also run 89 as recommended and it doesn't make any difference that's just the way it is. I'll try some 5w-30 next oil change and see if that makes any difference. Most likely though, 500 idle is too low and that's why it does it.

 

[madlouie23]

I've seen a few other threads on this but I've never found any resolution so I figured I'd ask and see if anyone else has similar experiences. I recently purchased a 2020 Ram 1500 big horn with the 5.7 hemi. The truck shakes very noticeably when at red lights or in park. I'm not new to trucks and I've owned many v8s that let vibrations through, they're big motors after all, but this is more erratic and feels like a misfire, however, the idle is rock solid at 500 with no variation. I had the dealer look at it and they said "they just do that" but I'm not entirely sold as I drove a few others and don't remember noticing it. With the hood up and the engine running I can see the whole motor shake a bit when it has it's "stutters". Would exhaust manifold issues (bolts or crack) affect back pressure enough to cause this or is it more likely a vacuum/throttle body issue?

I bought a 2023 and notice a similar idle issue but it seems to do right after I start driving and come to a stop after a short drive . Has a little over 1000 miles.

 

[madlouie23]

I bought a 2023 and notice a similar idle issue but it seems to do right after I start driving and come to a stop after a short drive . Has a little over 1000 miles.

I have 1500 miles on my 2023 and it does the same after a short drive. It doesnt do it all the time so its really hard to figure it out. I almost think it has something to do with the start/stop but who knows.

 

[theblet]

I have 1500 miles on my 2023 and it does the same after a short drive. It doesnt do it all the time so its really hard to figure it out. I almost think it has something to do with the start/stop but who knows.

Try disabling A S S and see what happened then

 

[JOzzz]

I’m getting the same and dealer said the same. My 2020 rebel didn’t do this. Tried cleaning the throttle body, replaced the MAF sensor, ran treatment and 93 multiple times, new plugs and insulators. I guess unless someone finds the culprit, I’ll just lived the cammed life feeling.

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[theblet]

I'm so used to it i don't even notice it anymore

 

[Darksteel165]

I’m getting the same and dealer said the same. My 2020 rebel didn’t do this. Tried cleaning the throttle body, replaced the MAF sensor, ran treatment and 93 multiple times, new plugs and insulators. I guess unless someone finds the culprit, I’ll just lived the cammed life feeling.

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What MAF did you replace?
The 5.7 HEMI doesn't have a MAF
I think you got duped...

 

[JOzzz]

What MAF did you replace?
The 5.7 HEMI doesn't have a MAF
I think you got duped...

My bad on the MAF. It was the air charge temperature sensor.


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[Cristyan]

Mine does this sometimes. I’m thinking it may be due to running 87 octane, but I haven’t tried 89 yet. Runs great when on the throttle. Another thought is to clean the throttle body.

Did you get a chance to try using 89 octane fuel yet, and if so, did you notice any improvement in how your vehicle runs during those times it acts up?

I've been experiencing a similar issue with my 2023 with around 12,000 km/7500 miles on it, and I'm curious to see if your experiments shed any light on the situation.

 

[theblet]

Did you get a chance to try using 89 octane fuel yet, and if so, did you notice any improvement in how your vehicle runs during those times it acts up?

I've been experiencing a similar issue with my 2023 with around 12,000 km/7500 miles on it, and I'm curious to see if your experiments shed any light on the situation.

I never did. I was thinking to try it when gas went back down to like $1.50 but that never happened.

Did you try it?

 

[Rick3478]

Weak injector? Differences or imbalance among injectors might have the most effect at extremely short pulse widths (idle). Just a theory.

 

[Cristyan]

I never did. I was thinking to try it when gas went back down to like $1.50 but that never happened.

Did you try it?

Got it, thanks for the update. I'll give the 50/50 mix of Costco's 87 and 91 a try. Appreciate the insight!

 

[23RAM]

Got it, thanks for the update. I'll give the 50/50 mix of Costco's 87 and 91 a try. Appreciate the insight!

I wouldn't bother. I've ran a few tanks of 89 to check mileage and performance and found a negligible difference, not enough to offset the extra cost. And it certainly didn't make the engine idle any "smoother".

If I was towing heavy regularly like 8k+, I might consider 89. But for daily driving and 5k towing on the weekends (twice a year 8k), I can't tell the difference between 87 and 89.