The truck is shaking from 1000rpm to 1500rpm while in park or neutral. I am not sure what it is and before I take it to the stealer I want input from you guys. I found the shake/vibration about a 2 weeks ago when warming the truck up before work. It was too warm for the high idle so i held the engine at ~1200rpm. I immediately noticed the shaking. It only happens in that 500 rpm window, not below or above. I have since ran fuel additive thru a full tank, changed the fuel filter, and switched back to the stock tune. None of which helped. It is actually worse with the stock tune. I checked injector balance rates with the predator, and all are in spec, with a couple near +-4. Again worse with the stock tune. I am out of ideas. Thanks in advance.
Chris

Forgot to add that there are no codes setting from this.

Have you ever had the water pump, or the engine dampner off?

Have you ever had the water pump, or the engine dampner off?

No. The only maintenance I've done on it is change fluids and rotate tires.

As soon as the throttle pedal moves off idle the balance rates go away. Typically when you feel the shake off idle it is an injector issue. Scan the balance rates and see where they are,that should give you a good indication of what is going on.

Checked balance rates on predator. I am assuming the injectors are listed in order on the predator screen. Not real sure what I am looking at here.

with pred on 65 with stock tune
N D N D
1. -3.4 -2.5 -3.4 -2.6

2. -1.4 -1.7 -2.0 -1.95

3. 2.0 1.9 2.9 2.4

4. -.85 -.65 -1.15 -1.1

5. 2.8 2.5 3.7 3.07

6. -2.2 -2.35 -3.2 -2.8

7. -.5 -.95 .5 -.21

8. -3.2 -3.1 -4.1 -3.9

Sorry about the above post. I can't get it to line up properly after I hit submit. Anyway, I also have a CEL now. Comes up with P0299 code. Don't know what that would have to do with the shaking. Thanks for the replies so far. It's looking like I may have to go to the stealer.:mad:

Went to the dealer this morning. They say I have a bad turbo boost pressure sensor. That explains the P0299, but not the shaking/vibration. Oh well, at least it's under warranty.

Keep us posted, hope youf oudn a good dealer.

Dealer has to order the turbo boost pressure sensor so it will be dropped of Monday morning for the work. They are saying the shake is due to probable bad fuel and to run a few more tanks thru to clean the system out completely. I think I'll run as much fuel conditioner/cleaner thru as is safely possible and change the fuel filter again in a few tanks. I wish I could find some B20 around here to clean the system out. At least these guys didn't claim the problem was from my "larger than stock" tires.:rolleyes: This service department seems pretty good so far, although they say they can't calibrate for my 285's. I still don't understand how anybody with a $200 programmer can calibrate for this and they can't with their couple thousand dollar techII. I am amazed at how much quieter the truck is w/o the Predator 65hp tune. I'm thinking I might leave the truck stock and just adjust the tire size. Anyway, thanks guys.

They won't adjust for tire size because it could screw with your ABS system.

:RockOn: :rocking: "Stock Don't Rock"

They won't adjust for tire size because it could screw with your ABS system.

Has anyone heard of this actually happening?

Has anyone heard of this actually happening?


I cant say for sure, but I would think you would have more potential for problems with the ABS system if you DIDNT adjust for the tire size. JMO.

I cant say for sure, but I would think you would have more potential for problems with the ABS system if you DIDNT adjust for the tire size. JMO.

That's exactly what I was thinking.