2008 5.3 rough 4cyl operation and transition

[akbrener]

running 192K miles on my 08 5.3. I have been noticing a ton more feedback through the body when the engine is cruising. when transitioning from 8-4 its pretty smooth, but when its running on the 4cyl mode it is very obvious and vibrates the truck and can feel it in my steering wheel. As I add throttle and it goes back to 8 its very noticable.. call it a "shiver". Trying to get to the summer before I have to tear into it or hopefully trade up to something new.. but still would like to sell with a good performing engine.

I had posted a while back about the truck hanging onto 4 cylinder mode at lower speeds when coming to a stop. this is still happening, I am sure it's all related.

Recently was up for its regular oil change and that had not changed anything, the cold start has maybe a very faint lifter tick but if it happens it goes away just as fast as I hear something.

Am I a candidate for a new VLOM plate? maybe time to change out the driver side engine mount? hopefully nothing internal (lifters, cam etc). There are no codes popping up, oil pressure looks real nice at all RPMS.

Thanks

 

[Jason in DLH]

Just curious the last time you changed spark plugs and wires?

 

[akbrener]

Maybe 10-15k miles ago.

 

[03catburban]

Load the engine up like in a brake torque but dont keep holding the throttle. You just need to blip the throttle while in gear to see you if feel a thud.

If So your driver side engine mount is broke ive replaced a many mounts for that issue

 

[iamdub]

running 192K miles on my 08 5.3. I have been noticing a ton more feedback through the body when the engine is cruising. when transitioning from 8-4 its pretty smooth, but when its running on the 4cyl mode it is very obvious and vibrates the truck and can feel it in my steering wheel. As I add throttle and it goes back to 8 its very noticable.. call it a "shiver". Trying to get to the summer before I have to tear into it or hopefully trade up to something new.. but still would like to sell with a good performing engine.

I had posted a while back about the truck hanging onto 4 cylinder mode at lower speeds when coming to a stop. this is still happening, I am sure it's all related.

Recently was up for its regular oil change and that had not changed anything, the cold start has maybe a very faint lifter tick but if it happens it goes away just as fast as I hear something.

Am I a candidate for a new VLOM plate? maybe time to change out the driver side engine mount? hopefully nothing internal (lifters, cam etc). There are no codes popping up, oil pressure looks real nice at all RPMS.

Thanks

I'd replace the VLOM as a relatively quick and cheap attempt. Be sure you get the updated one. You'll also need new intake manifold gaskets. When you have the VLOM off, you can get a few glimpses of the cam and lifters just to see if there's anything alarming.

If you find the engine mount is broken, I recommend replacing it with the Hummer H3 mount. I'd recommend replacing both, but it's likely the driver side that's really blown, at least for now.

 

[akbrener]

I'd replace the VLOM as a relatively quick and cheap attempt. Be sure you get the updated one. You'll also need new intake manifold gaskets. When you have the VLOM off, you can get a few glimpses of the cam and lifters just to see if there's anything alarming.

If you find the engine mount is broken, I recommend replacing it with the Hummer H3 mount. I'd recommend replacing both, but it's likely the driver side that's really blown, at least for now.

i think we talked about this last time I posted, i appreciate the advice again. The low speed thing kinda went away the last oil change but now it’s back and bringing more along with it. Hopefully just the solenoids and not anything more. Do not want to spend 200 on a AFM delete if there’s internal issues.

 

[iamdub]

i think we talked about this last time I posted, i appreciate the advice again. The low speed thing kinda went away the last oil change but now it’s back and bringing more along with it. Hopefully just the solenoids and not anything more. Do not want to spend 200 on a AFM delete if there’s internal issues.

AFM delete is way more than $200, unless someone is giving you the parts! The new VLOM and IM gaskets would be around $200. This is a cheap and quite probable fix compared to AFM delete or any internal work.

 

[akbrener]

AFM delete is way more than $200, unless someone is giving you the parts! The new VLOM and IM gaskets would be around $200. This is a cheap and quite probable fix compared to AFM delete or any internal work.

I meant the range module thing to just tune it out. If I wasn't pushing 200K I would probably look at the full cam swap and associated goodies.

 

[iamdub]

I meant the range module thing to just tune it out. If I wasn't pushing 200K I would probably look at the full cam swap and associated goodies.

Ah. I gotcha.

Hell, I waited until I hit 200K before I tore mine apart to delete it. Ended up doing a bunch of performance stuff to it and now drive it harder. Didn't disassemble the rotating assembly so all the bearings, etc. are original. Recently took it on an 1,800-mile trip with the fam to Tampa, Florida and towed a golf cart back.

"MileAGE is just a number"

 

[Dustin Jackson]

I meant the range module thing to just tune it out. If I wasn't pushing 200K I would probably look at the full cam swap and associated goodies.

@akbrener I am running the Range AFM disabler. Nothing fancy just keeps it in v8 mode. Works as intended.