So I had a similar issue with my '09 Avalanche. I was at 70k miles and literally 1 mo. outside of the 5 year warranty. I detailed my post Page 12 of this thread (around October 2014). My truck was also babied (garage kept, never offroad, frequent washes). I did like to joyride in the snow, but outside of that just normal driving.

Since you have 100k, I'm assuming you purchased the extended warranty package. This did seem to have an impact on GM providing assistance. We are also family friends with the Dealership that did the fix, so perhaps that played into a bit as well.

My truck broke down in East Lansing, MI and the dealer there had quoted me a rather large amount...$5k exactly, which seemed strange it worked out to a nice even number. When I questioned them on the high cost, they said GM would cover 50% and brought it down to $2,500. If the original amount was $5,016.47 or something more normal I may have believed them and went with it.

I had also paid $250 up front for an engine tear-down and diagnostic, sent the analysis to our Dealer Friends and they said based on the report it should be approx $3,000 for the fix. They called up GM and were able to negotiate a 60% GM, 40% myself cost split. The $500 tow charge was also passed along to GM. So I ended up paying about $1,200 out of pocket for the repair. The cam and lifters were replaced along with a few other odds and ends.

Hopefully that gives you a good idea of the potential out of pocket costs if you go the Dealer option. I didn't have the time to attempt any of the SeaFoam fixes and had to go Dealer. I regret to say I haven't been able to drive it since the repairs, my grandpa has been using it though. I move back to the USA tomorrow and will be picking it back up, I'll let you know if there are any issues.

Best of Luck!

 

So I had my '09 Avalanche fixed up back in October, but am just now driving for the first time since (had lived in Singapore for a few months). The engine seems to be running fine, but there is a new noise and lower oil pressure on idle after hot engine.

New Noise
There is a new noise, not the loud clanking that was of concern for the engine problems. This a higher-pitched, but softer noise. It only happens when I hit the accelerator (not cruising or braking). It almost sounds like fluid flowing through some type of rotary wheel gauge. The sound is coming from the driver side and perhaps near the front wheel well. Going to schedule an appointment this week to see what that might be.

Low Oil Pressure
This is the one that really scared me as it was the indicator of the original problems. Basically when I first started running the truck, oil pressure was up around 40 psi on idle and pretty consistent. I had been highway driving for about 3 hours and when I got off the highway and came to a stop, I noticed my oil pressure dropped to 20 psi at idle (600 RPM). *key in the nightmare*

I checked my oil level in the morning and everything seems normal (clean oil and no loss).

I did a bit more forum searching and found that the late model Avalanches (11-13) also seem to have lower oil pressure on idle for hot engines. There has been some speculation that this was a fix to account for the AFM issues of the 07-10 model vehicles. A few posters have indicated that as long as a minimum oil pressure of 10 psi per 1,000 RPM is maintained, all is well.

I'm not that savvy with the truck to know if that rule of thumb is correct. I'm going to ask the dealer if they did anything here during the engine fix that would make this a normal operating mode. I have a 7 hour trip coming up this weekend and don't want the truck to crap out on me.

Has anyone else with an engine fix noticed lower oil pressure on idle with a hot engine?

 

thanks for the information and the pictures. I being thinking of adding a engine oil catch can on my 2010 tahoe (to prevent carbon build-up on my valves).

 

Unfortunately not true. My 2008 GMC Sierra crew cab has the L76 VortexMax aluminum Holden motor with AFM. And unfortunately again, last December at 97,000 miles the front left lifter collapsed. I had the dealer replace all the lifters and all the valve springs for $4300 hoping to get another 100,000 out of the engine.

Then yesterday, 4 months and 4,000 miles later, the same thing happened.

Frustrated? You bet! Luckily the dealer guaranteed the work for one year.

We shall see what happens. Love the truck, love the HP the motor develops, especially for towing. But the 10 MPG thing sucks. But I can't expect it to be a damn quick truck AND get good mileage.

 

Not sure if this is mentioned earlier in the thread. I've noticed recently that if I'm running in manual mode, if in 6th the AFM will still activate, but if I select 5th it won't come on. So, for around town driving up to 50 mph or so I've just been selecting 5th. On the highway I'm usually over 70 so AFM rarely comes on.

 

I noticed this as well, I am using this method until I figure out what to do next. My 2009 GMC SLT with 75000 miles (115000 km) started making "rubbing" noise 2 weeks ago, noticed it when I returned from a highway trip, needed 2 qts of oil, but oil pressure was still normal. Took it to GM dealer and without dismantling it, they say it needs new lifters and cam (indicates they have seen this more than a few times) to the tune of $6200 Cdn, new motor is $9100 cdn. I have changed oil and filter and I am monitoring oil usage, have not added anything yet 500 miles. May look at oil separator for PVC. Have contacted GM Canada and they have said they will not cover anything as I am over the 5 yr warranty (but significantly below 160000 km mileage portion, I have 115,000 km on truck. Also am looking at getting it repaired by 3rd party, not GM as it is significantly cheaper $5000 Cdn. The shop I talked to has 2 in now for this repair.

 

rufas11 welcome to the forum...
Sorry to hear you are having this issue... on my 2007 5.3l with AFM, at the first sign of oil consumption (about 97k miles) I added the Range AFM disable, this has stopped the oil consumption and the engine has been quite...prior to adding the Range device, I sent my oil in for analysis and it showed high metals....
I am about to send my oil in for a third analysis for the past 6000 miles ( now at about 109k) I have had not oil consumption and its all been with the range device installed so no AFM activity in the 6k miles... yes MPG is impacted but if the numbers come back good for oil results I'll be happy and confident she will go another 100k miles or till 2017 when I plan to get a new truck

 

Was wondering if others have had any luck in using additives to clean / coat (slick 50, XADO, etc) engine, i have tried seafoam in gas supply but not directly into oil yet. Noise seems to be the same, not getting worse (yet), looking at AFM disabler as well.

 

I was watching oil pressure gauge while driving and it seems to be lower at idle when oil is hot versus cold, also thought it was a little higher, also it seems a little higher in V4 mode than V8 mode when driving (at 1500 - 1800 rpm range), although it is just looking at the gauge on the dash (still between 40 - 50 psi)

 

I have a little over 125,000 miles on my 2013 Silverado I'm experiencing fuel management system failures my traction lights and check engine light come on and after taking it to get the code read it says I have o2 sensor issues. I took it to a mechanic and he said that's not the issue at all it is with the flawed engine design from the lifters not getting proper lubricant when switching over to fuel management mode. They gall and start sticking and It also causes motor Skip. It stalls and accelerates on its own. I have called and reported this to GM and I'm trying to get a recall setup for these motors. The mechanic has done several of these in the past few weeks on the same motor. How can a Toyota Motor last over 300000 miles with no issues and GM cannot build a motor that will last 120,000. Anyone else experiencing this?