Trying to resolve engine shake

SouthGeorgia · September 12, 2017

Not a prevalent poster here. Actually probably only posted once back right before I bought this truck. I have a 2012 GMC Sierra 1500 Z71 with the 5.3L. It has Around 76,000. Bought it basically new from original owner with 15,000. Haven't done anything crazy with it or extra mods.

I noticed a few other folks here posting about this issue, but I'm not a car guy so honestly I have no idea what people are saying in response. Ha.

About two years the entire engine began to rattle. Traction control came on, check engine light came on. Sound familiar? Code showed, I believe First Cyl. Took to the dealership and they just replaced the Cyl and sent me on my way. About 6 months later, same thing. This time it was a different Cyl. I go to my long time (20+ year; truck is out of warranty by now) mechanic and he pulls a bulletin which shows procedures for putting some plate in which resolves the issue. (Bulletin was in place when GMC dealer first looked at it when it was under warranty which is annoying) Paid $600 or $700.

Well, since then the engine issue has happened about twice more. Now, at idle, the RPM's just don't always quite seem the same. Needle moves up and/or down sometimes and the engine just doesn't feel completely in synch. Could the engine shake have caused permanent damage?

Any idea what to do? I drive a lot for work and honestly don't have time to send my truck to get fixed every 6 months. I'm also thinking of just selling it and moving on.

It's Tim · September 12, 2017

Has this vehicle had scheduled maintance in the past?

First it needs to be verified that the vehicle electrical system is functioning correctly. Then it needs to be scanned for pending/stored codes and a fuel pressure check would also be in order. Just guessing gets expensive quickly and rarely fixes the actual issue. If you don't have the knowledge and tools required it may be a lot less expensive in the long run to just take it to a trusted shop.

diyer2 · September 12, 2017

Has this vehicle had scheduled maintenance in the past? This.

Took to the dealership and they just replaced the Cyl and sent me on my way. Piston? Lifters?

I noticed a few other folks here posting about this issue, but I'm not a car guy so honestly I have no idea what people are saying in response.

So what are you looking for? You can't fix it, right? No one can tell you what the problem is exactly.

I go to my long time (20+ year; truck is out of warranty by now) mechanic

You answered your own question IMO.

My 2012 Sierra runs perfect. 60 k miles. Bought with 41 k miles. Maintenance better than manual suggests. Sorry you're having trouble.

SouthGeorgia · September 12, 2017

All fair questions. I have done regularly scheduled maintenance and get synthetic oil changed religiously.

Honestly, I do not know what I'm looking for, I'm just asking if anyone can provide some sort of insight. I don't want to get rid of it, but I'm also struggling to find a resolution.

I go to my long time (20+ year; truck is out of warranty by now) mechanic

You answered your own question IMO.

Not sure what you mean here. Are you suggesting dealership visit instead?

MaverickZ71 · September 12, 2017

Not a prevalent poster here. Actually probably only posted once back right before I bought this truck. I have a 2012 GMC Sierra 1500 Z71 with the 5.3L. It has Around 76,000. Bought it basically new from original owner with 15,000. Haven't done anything crazy with it or extra mods.

I noticed a few other folks here posting about this issue, but I'm not a car guy so honestly I have no idea what people are saying in response. Ha.

About two years the entire engine began to rattle. Traction control came on, check engine light came on. Sound familiar? Code showed, I believe First Cyl. Took to the dealership and they just replaced the Cyl and sent me on my way. About 6 months later, same thing. This time it was a different Cyl. I go to my long time (20+ year; truck is out of warranty by now) mechanic and he pulls a bulletin which shows procedures for putting some plate in which resolves the issue. (Bulletin was in place when GMC dealer first looked at it when it was under warranty which is annoying) Paid $600 or $700.

Well, since then the engine issue has happened about twice more. Now, at idle, the RPM's just don't always quite seem the same. Needle moves up and/or down sometimes and the engine just doesn't feel completely in synch. Could the engine shake have caused permanent damage?

Any idea what to do? I drive a lot for work and honestly don't have time to send my truck to get fixed every 6 months. I'm also thinking of just selling it and moving on.

Dealer replaced the Cyl?? Say what? Maybe the spark plug on the 'cyl' both times.

Sounds to me like you have the very common, infamous AFM oiling problem. Motor oil leaks past the piston rings and gets sucked through the PCV system into your intake, which fouls the spark plugs and leads to a rough idle. I believe the 'plate' you are referring to is a part of a GM TSB (Technical Service Bulletin) with procedures on how to mitigate this problem.

Read the "Is your truck using oil" poll that is pinned at the top of this forum for much more information on this problem and what you can try to do about it. This problem also can contribute to cam and lifter problems, which in conjunction with the AFM-altered firing order on these engines and today's poor fuel, can turn one of these GM small blocks into a real cocktail shaker.

I have to run the best premium I can find, along with Chevron Techron Fuel System (not Fuel Injection) cleaner all the time to keep mine running, and that's with the TSB procedure having been performed. You can clean the spark plugs or install new ones, and it is better for a short while, and then they get fouled, it runs rough, and starts throwing a CEL with misfiring codes.

If I had it to do all over again, I would have INSISTED on having the engine torn down and new piston rings installed. But I didn't trust my 'good' dealer to do that. They're good guys and they try hard, but it's kind of a dirt-floor operation back in the shop.

Here is an 'executive summary' on what you can look into doing:

http://www.gm-trucks.com/forums/topic/204412-rough-idle-and-engine-misfire-issue/?p=2025690

diyer2 · September 12, 2017

I go to my long time (20+ year; truck is out of warranty by now) mechanic

You answered your own question IMO.

I guess I missed something. You post about you're engine problems, admit you don't know much about engines. So what are you looking for from us to fix this. We can't diagnose it for you. If we could sounds like you can't do the repairs.

You're alternative is a mechanic.