2009 Silverado troubles

[Wayloncle]

I bought my truck new in '09, about 45k miles it started missing a little and the dealer replaced the spark plugs under warranty. I asked why a plug was fouled, there has to be something wrong for oil to get to a plug to foul it, eventually the tech said the active fuel management causes it (shuts 4 cylinders down when not needed) something about a little Unburnt fuel eventually fouls it. About 80k miles I changed them because it started missing again, now with 100k miles it's doing it again. I pulled the #1 plug and it looks terrible, #3 looks clean as can be.

I wish I could just turn off the fuel management crap, I can order a new tuned computer that will shut off, but that's about $600, and I don't think it will solve my issue. I got a couple new plugs this morning and borrowed a compression tester to test #1 cylinder, I'm thinking something is going on like needing a ring job or something, hope not but I'm about to go out and tinker with it and see what I can figure out.

If I had the choice, I would have opted to not have the active fuel management crap:-/ the system is the reason the engines around this model lose oil as well, but according to Chevy it is completely normal to lose a quart or so every 3000 miles

 

[Bruce]

Wow, that is a lot of oil loss!

Is it a 5.3?

 

[Wayloncle]

Yep 5.3.
This is the #1 plug, the rest look fine:-/
Compression test seems normal.

I learned something today, if you want to turn over your engine without it starting push the accelerator to the floor before turning the key, it shuts off the injectors.

 

[sbowles]

I have a 2010. Replaced plugs twice within a year for the same issue. Dealer finally installed a newly designed valve cover that is supposed to help with this a couple of months ago. He said there was a service bulletin on some of these. It's only been a couple of months but hopefully it helps.

 

[Bruce]

If you swap that 5.3 for a similar age 6.2 you will lose the active fuel management, gain hp and torque but start wondering where the fuel went!

 

[scot71]

I had a 2009 Sierra that didn't foul plugs, but was notorious for using a couple quarts of oil between changes (5000 - 6000 miles).

Have you looked into one of these? I didn't personally buy one, got rid of the truck before that. Might be an answer though.
http://www.autoanything.com/performance-chips/range-active-fuel-management-disable-device

 

[bronze_10]

The whole idea of the fuel management system.is to get better fuel mileage... it doesn't seem right that raw fuel and oil would end up in a cylinder shut down by the computer to have less fuel consumption. .... my 2005 durango has the same feature but I have never had an issue with it... 110 thousand miles and it still has the original plugs... now that I think about it..... it maybe time to change those.. but still.. something seems off there.

 

[Wayloncle]

If you swap that 5.3 for a similar age 6.2 you will lose the active fuel management, gain hp and torque but start wondering where the fuel went!

I would completely be fine with the extra fuel! If I have to do engine work I will probably go that route.

 

[Wayloncle]

I have a 2010. Replaced plugs twice within a year for the same issue. Dealer finally installed a newly designed valve cover that is supposed to help with this a couple of months ago. He said there was a service bulletin on some of these. It's only been a couple of months but hopefully it helps.

I had the valve cover replaced at around 20Kmiles for the oil issue, didn't fix a thing with mine....they said they replaced it anyway:-/
Hopefully it fixes yours!

 

[Wayloncle]

I had a 2009 Sierra that didn't foul plugs, but was notorious for using a couple quarts of oil between changes (5000 - 6000 miles).

Have you looked into one of these? I didn't personally buy one, got rid of the truck before that. Might be an answer though.
http://www.autoanything.com/performance-chips/range-active-fuel-management-disable-device

Thanks!
That's cheaper than the tuned computer that I was thinking about ordering.

 

[scot71]

I had the valve cover replaced at around 20Kmiles for the oil issue, didn't fix a thing with mine....they said they replaced it anyway:-/
Hopefully it fixes yours!

Everything that I've read. Says it's an accumulation of oil on top of the head (due to the FMS) that causes the oil consumption. It pools on the head and slowly gets burned off through the PCV. It's not enough to notice, but enough to cause a problem.

 

[veedubtek]

Really different, but likely the same - on direct injected cars, we have big problems with the pcv system and oil recirculation clogging up intake ports (because fuel is sprayed directly into the combustion chambers, so no fuel to wash the oily residue through and it cokes up on the backside of the valves). We can circumvent this problem with a catch can. Knowing nothing about your truck first hand, but reading through here, it sounds like a similar solution would be beneficial to you.

 

[Wayloncle]

@veedubtek probably is the same situation, I'll read more about that.

I figured out that if I put my truck in Manual instead of Drive it won't activate the AFM, as long as I leave it in 5th and don't shift into 6th.
I'm going to drive it like that for a while and pull the plug to see what it looks like.

 

[Bruce]

@veedubtek may have the best solution but I still prefer the .9 liter upgrade.

 

[jcsmith77]

I have a 2011 5.3 with 60k and the exact same issue that I got them to do the service bulletin fix for the new valve cover under the powertrain warranty that is about to expire. That was about 1k miles ago and it feels like it is starting to miss at idle again. I haven't had time to pull the 1 or 7 plugs to check. On mine the 1 cylinder plug was oily but not destroyed. The 7 plug was missing pieces of porcelain and looked like it had 200k on it. Is there anything else they will do? I am days from running out of PT warranty.

 

[Wayloncle]

I have a 2011 5.3 with 60k and the exact same issue that I got them to do the service bulletin fix for the new valve cover under the powertrain warranty that is about to expire. That was about 1k miles ago and it feels like it is starting to miss at idle again. I haven't had time to pull the 1 or 7 plugs to check. On mine the 1 cylinder plug was oily but not destroyed. The 7 plug was missing pieces of porcelain and looked like it had 200k on it. Is there anything else they will do? I am days from running out of PT warranty.

Funny you say that about your #7, when I changed all of mine in August one of them had a little chunk of porcelain missing, I can't remember which one it was now.

They wouldn't do anything else for me, if I had some warranty left I wouldn't stop trying!

If my little experiment of driving in manual to keep it in V8 mode works out I'm going to order the device mentioned above.

I thought it was only the '08-'09 models, I didn't think it went all the way up to '11s.

I haven't been on there in a long time but Chevy trucks forum used to have a whole lot of posts about this nonsense.

 

[jcsmith77]

It is pretty frustrating, only vehicle i have ever bought new and I am running out of time on the factory warranty, not miles. I seriously might consider that device as well. If I get some time this weekend, I will pull the plugs and look as they are basically new. Funny thing was that the guy at the dealership told me it was not a problem to get oil on the plugs......sigh

 

[Wayloncle]

Funny thing was that the guy at the dealership told me it was not a problem to get oil on the plugs......sigh

I couldn't believe it the first time I was told the oil loss was completely normal for 5.3's, I argued with the guy because I had a 2004 Silverado before this one and my wife still had her 2004 Tahoe both 5.3's and never lost a drop of oil. Then he said "well, normal for the ones with AFM". So there's a problem with the Fuel management system? "No, no problem, it's normal"

They were all very careful with their words to be sure to never say that it was a problem.

 

[2nazt]

My Ram works without the cylinder deactivation as long as it in manual mode 6 it won't shut down. I also have a catch can and amazed by the amount of oil it accumulates.