Not to steal your thread buddy but I have this SAME issue. It's not idling roughly but it's just vibrating to all hell. It drives me insane haha

 

It sounds like you cleaned things properly. The MAF doesn't take much, just spray the element (if you sprayed the part that looks like a light bulb filament). There are one or two ports on the throttle body that I usually spray through.

It's nearly impossible (for me) to identify the nature of your vibration, but these trucks are not silky smooth to begin with. I feel it in mine but I haven't tried to isolate the exact RPM range of the vibration. Mostly because I know things aren't perfect and I don't care that it vibrates a bit.

As long as you were able to spray the throttle body and wipe the throat clean as well as the backside and edges of the butterfly. And that you didn't score the surface I think you probably did it right.

Have you seen any check engine light. I think he Camshaft actuator thingy causes vibrations too but if I remember right, it will throw a code when it's going bad.

 

At first I was thinking I was just spoiled with my previous V8, but this isnt a vibration due to the lack of smoothness. Its getting harder to overlook and ignore.

I assume the camshaft thingy you mentioned is Exhaust Camshaft Actuator Solenoid?

I read the how to for that yesterday as well. I would really like to take the throttle body off again next week and set it on my dining room table and really clean it. I also may just wait till I get paid and buy of of Supermods ported TBs. It just seems like a TB thing to me, but I'm not a mechanic(more along the lines of a ******* with a set of sockets). I just couldnt get the fuel line connector off. I was scared I was going to brake the pin.

I don't want to change the plugs unless its a last resort.

 

it could be the exhaust Camshaft Actuator Solenoid/Variable Valve Timing Sprocket i change mine on my 3.7 whenever they break.

Also, the grayish clips on the 5 ign boots tend to vibrate off a little, a push of them in could help correct it too... jusst something little to check.

 

Motor mounts maybe :shrug:

 

Yeah, especially if one of them is a hydraulic mount.

 

Go ahead and add some fuel system treatment, but higher octane fuel won't do anything, except cost more.

 

My mechanic told me that a can of seafoam and high octane gas is almost as good as having the injectors cleaned. I do that to a 2005 suburban I got seems to make a big difference, esp after long trips.

 

Had no luck with the fuel treatment.

Researched some Camshaft Actuator Exhaust solonoids.

In my town there was a dorman, a delphi and the chevy dealership had a OEM part. THe GMC dealership ( I dont think it should matter )didnt have one.

I unhooked the battery for 15 minutes, replaced the actuator, which was clean in the plug and around the outside. The inner portion was missing a screen.

I also found the right size torx driver and cleaned the MAF properly.

Started her back up, the vibration was still there but.... After driving for about 50-60 miles from home around town, to tractor supply and what not the vibration was steadily getting better. It is not gone, but the actuator definitely helped.

 

From my readings, the missing screens didn't help your matter any. Hopefully once the system has relearned (should be after 60 miles) your driving it will be as smooth as it should be. If anything, one step closer and the replaced actuator sounds like it was necessary anyway.

 

Bringing this back up.

This vibration has definitely gotten worse. Especially at cold starts. Yesterday when I left work, the engine surged for 20-30 seconds, then rpm came down and the vibrations came back. Checked for codes, there wasn't any pending....

I'm baffled. Would I notice if one of the cylinders wasn't firing correctly due to a coil pack or something loose? When the engine mis-fires does it always throw a code?

 

Everything I have read says yes, you'll get a light with a misfire. But I can't speak from experience. It has been true on another vehicle I owned though.

Does it run well once it's going or does it always run unusual? Is there anyway you can check fuel pressure? Surging could be a result of a vacuum or intake leak too but I wouldn't know where to start checking something like that. Sorry.

 

Once it gets about 1500 RPM, everything seems fine.

Doesn't matter if I drive for 20 seconds or 2 hours, it will still vibrate in any gear from 1000-1500 RPM.

My fuel economy is below average....

Mind you I have 235/75/15 tires on there, the stock being 265/75/15

Which techincally would make me seem like im getting better mileage, but I have put 1000 miles on it in the last 1.5 weeks, and barely made the 300 mile per tank mark.

 

I'd expect better mileage from the smaller tires too. As long as you're factoring in the properly traveled distance.

I can't think of anything else to cause erratic idle at low RPM.

 

Its more of the vibrations > erratic idle I'm worried about. I may try swapping 4&5 coils around when I have time to see if that makes any difference.

 

I was having this issue and one of my motor mounts was completely toast. Endend up changing all 3.

 

How much did that run you?

And how did you find out?

 

Any advice on changing motor mounts?

 

Check this link out.

http://www.355nation.net/forum/supersparkz-spark-plug-spring-upgrade/47581-supersparkz-spark-plug-spring-delete-upgrade-prices-ordering-info.html

I found my vibrations were coming from the low current transfer in the spring in the coil packs. Build them or buy, but they solved my problems.


T

:th_woot:

 

Might sound crazy but have you thought about something as simple as the heat shields? I once read a how to for removing them because my truck has a similar issue to yours. Havent removed them yet though...

 

If anyone is experiencing a tinny sounding vibration in their exhaust system at around 1800 rpms, which tends to get louder the longer you run the vehicle, the problem is the muffler. After three trips to the dealer to try to find the problem, I took the service manager for a ride and let him hear the sound for himself. He checked out the entire exhaust system, including all the heat shields, and found that the baffles inside the muffler had rusted and were what was vibrating. He replaced the muffler with a new one, and the problem is solved!!!