Shake/Vibration after CAI + Ported Throttle Body Install

Hi all,

New user and New Ram owner here. I purchased a 2017 Ram 1500 5.7l back in May. I've since installed an S&B CAI and a ported throttle body from Moes Performance.

I noticed a vibration/shake at idle after the install (not felt at other speeds). There is no check engine light on to help diagnose this.

I've verified the CAI is connected correctly with no leaks. The sensor is also installed correctly. I've unplugged the battery to reset the computer but no change.

Two possible scenarios that I can think of. I either need a tune to adjust the intake settings or I need to upgrade my exhaust to handle the increased intake.

I was wondering if anyone has any recommendations or further troubleshooting I could try?

Thanks!

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Did you make sure that rubber O-ring didn't get pinched under the throttle body?

I haven't checked that. I'll remove the throttle body and intake tube going into it tonight and see if anything looks out of place.

Is there anything else you'd recommend I look for when I'm in there?

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No 'gorilla' force when tightening the TB down, that's a plastic manifold and the threads can strip out.

Also, check that your crankcase breather isn't plugged. That is the hose from the driver's side that crosses under the engine cover into your S&B box.

If that were not drawing/venting it could mess with the function of your PCV which dumps into the manifold right at the base of your TB.

Thanks Casper, I'll keep that in mind too.

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It is strange to pick up any kind of vibration from these upgrades, so I would follow the advice posted above. Double check the O ring gasket under the throttle body and make sure the breather hose is secured both at the oil cap and on the airbox. I would also check the IAT sensor to make sure it was not damaged during install.

Thanks all, will look at all of these tonight after work and see what I find.

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Hey all, thanks for the tips. I removed the intake tube from both the TB and airbox and removed the TB to check the gasket, no issues there. I double checked the IAT and didn't see any issues there. I also verified that the breather hose is pulling air from the airbox.

Did this all with the battery disconnected. Didn't notice a difference after reassembling. Visible shake in the engine that shakes into the cab still.

Might be me overreacting/overanalyzing something completely normal, but it's still new and I'm getting used to the beast.

Follow-up question. Do any of you have a visible shake in the motor while at idle? If so then I'm just overreacting and it's probably normal. If not, any other suggestions?

Is it not throwing a check engine light? The hemi isnt the smoothest motor in the world but it shouldnt be shaking the truck by any means. To get the motor to shake would lead me to either a disconnected injector or coil pack.

Does the engine rev out properly?

This is the internet so we all see problems different. My truck will shake a little at a light when in gear but again I dont know what you are feeling.

You can ask the internet all day long.
You will probably get a hundred different answers and will be no wiser.
The easiest way to verify if your problem lies in your upgrades - go back to stock!
Airbox & TB change - 15-20 mins tops.

DavidN said:

You can ask the internet all day long.
You will probably get a hundred different answers and will be no wiser.
The easiest way to verify if your problem lies in your upgrades - go back to stock!
Airbox & TB change - 15-20 mins tops.

Click to expand...

Video helps a ton if the OP can get one up for us to see

Hey guys,

WilliamS - No check engine light and it revs normally no issue getting it to 5k+.

It's hard to explain the shake in words but it's noticeable in the cab and at the engine.

David N - good suggestion, if I can't figure it out here I can give stock parts a go.

2nd piece of possibly relevant info I didn't mention. I was rear ended first month of owning the truck. Possible exhaust issue as a result?

I do have a video although it's nearly impossible to see the shake in the engine you can get a listen. (Hopefully the link below works.)

https://drive.google.com/file/d/1WO7O5Gp-9s1xn9oSgd1wGq0z8-zXfwpUWg/view?usp=drivesdk

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bottbr said:

Hey all, thanks for the tips. I removed the intake tube from both the TB and airbox and removed the TB to check the gasket, no issues there. I double checked the IAT and didn't see any issues there. I also verified that the breather hose is pulling air from the airbox.

Did this all with the battery disconnected. Didn't notice a difference after reassembling. Visible shake in the engine that shakes into the cab still.

Might be me overreacting/overanalyzing something completely normal, but it's still new and I'm getting used to the beast.

Follow-up question. Do any of you have a visible shake in the motor while at idle? If so then I'm just overreacting and it's probably normal. If not, any other suggestions?

Click to expand...

I've had a very slight rpm variation at low idle since about 50K on the engine--less than 50 rpm--a "flutter," but PCM is obviously adjusting something. Recently it got more pronounced, but with over 57K miles and spark plugs due at 60K (older Hemis have shorter plug life) I guessed it was dirty induction. A can of Seafoam cleaned it right up. Now I'm back to the slight "flutter" at low idle and suspect the new plugs will be the answer (TB is spotless thanks to a catch can, plug wires and coil packs are all good and I've run a quality injector cleaner through several times).


One last troubleshooting thought, probably not cause, but easy elimination. Why not put the stock TB back on and see if anything changes. The CAI is just air, and you're still naturally aspirated so its unlikely to be an issue. But if the stock TB doesn't change anything, you probably had vibration all along and just didn't notice until you started modifying things.

Another thought, these are 400hp Hemi's, so there is probably a little bit of "cam bump" at idle? It's just kept under control with computers these days, unlike our old carbureted cars. Heck, my 400hp Ram Air GTO 400 really shaked and bumped!

bottbr said:

Hey guys,

WilliamS - No check engine light and it revs normally no issue getting it to 5k+.

It's hard to explain the shake in words but it's noticeable in the cab and at the engine.

David N - good suggestion, if I can't figure it out here I can give stock parts a go.

2nd piece of possibly relevant info I didn't mention. I was rear ended first month of owning the truck. Possible exhaust issue as a result?

I do have a video although it's nearly impossible to see the shake in the engine you can get a listen. (Hopefully the link below works.)

https://drive.google.com/file/d/1WO7O5Gp-9s1xn9oSgd1wGq0z8-zXfwpUWg/view?usp=drivesdk

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Click to expand...

You're zoomed in way to close to be able to see shaking. I don't see anything in that video that would cause alarm