AFM Problems

[StockHoe]

Is anyone else experiencing problems with their AFM engines. Every time the Tahoe is in V4 mode, it shudders and vibrates like crazy. It feels like I'm driving on gravel. If I put it into 3rd gear or step on the gas it goes away because its now in V8 mode. It's so bad and frustrating that I stopped by Nissan today to look at the Armadas. Can we disengage the AFM or shut it off some how? This is the worst engine design. Not to mention I have to drive around with oil jugs because this thing likes to eat oil like a fat kid eats cake.

 

[Vgreid]

Mine didn't shudder like yours, but I disabled it because of oil consumption issues. After doing that and a few other minor things, my oil consumption has stopped. I also got much better throttle response and improved engine braking. To summarize what I did:

- Range AFM delete stopped the 4cyl mode, probably the cheapest way to do this at around $200.
http://www.autoanything.com/performance-chips/range-active-fuel-management-disable-device
- Techron & Lucas Upper Cylinder Lubricant (use your favorite) in a few gas tanks to help clean the valves and cylinders
- AutoRx (use your favorite) in the oil for one cycle to break down sludge and try to free up the rings
- added a catch can for excess oil spray and vapors

It took about 5,500 miles of driving for everything to right itself, but now I am 1,000 miles into this oil change with no oil consumption. Obviously, ymmv.

For more details, see the thread I had on the subject ...
http://www.tahoeyukonforum.com/forum/showthread.php?t=64622

My recommendation is the same as what I did, but at a minimum, go the Range Delete route. This will solve your shuddering issue and get you headed down the right path to resolving your oil consumption issues.

PS: I thought it was funny you mentioned carrying around oil. In my other link I have a short video and one of the things you'll see in there is that I used to carry extra oil in the center console ... lol!

---------- Post added at 01:47 PM ---------- Previous post was at 01:30 PM ----------

Here is another thread on the topic, and no, you are not alone on this!

http://www.tahoeyukonforum.com/forum/showthread.php?t=64560

 

[992dr]

Is anyone else experiencing problems with their AFM engines. Every time the Tahoe is in V4 mode, it shudders and vibrates like crazy. It feels like I'm driving on gravel. If I put it into 3rd gear or step on the gas it goes away because its now in V8 mode. It's so bad and frustrating that I stopped by Nissan today to look at the Armadas. Can we disengage the AFM or shut it off some how? This is the worst engine design. Not to mention I have to drive around with oil jugs because this thing likes to eat oil like a fat kid eats cake.

How do you know its in V4 mode? This is something I never got to experience. Before I had work done to mine, it was a joy to drive. After the work, its never been the same.
Also, does this only happen when you cruise at the same speed?
I ask because I have very similar, hell identical symptoms but my DOD has been disabled for a long time. If I drive more aggressive or drop it into 3rd, as long as I get by it shifting into 4th in a hurry, nothing happens. Its very odd.

Disabling the DOD/AFM will help with your oil consumption. I just changed my oil last weekend and from the looks of what came out, it didn't consume much if any.

 

[Vgreid]

The instant fuel economy readout on the DIC shows whether it is running in V8 or V4 mode. (I know it was only reading 9mpg at the time but I was towing a 7000+lb trailer)

 

[992dr]

Gatcha, I don't have that option in my PPV. Its basically a stripped down Tahoe.
I'm not sure how else I would've been able to tell it was engaging or not.

 

[AZSCTACO]

Is anyone else experiencing problems with their AFM engines. Every time the Tahoe is in V4 mode, it shudders and vibrates like crazy. It feels like I'm driving on gravel. If I put it into 3rd gear or step on the gas it goes away because its now in V8 mode. It's so bad and frustrating that I stopped by Nissan today to look at the Armadas. Can we disengage the AFM or shut it off some how? This is the worst engine design. Not to mention I have to drive around with oil jugs because this thing likes to eat oil like a fat kid eats cake.

Mine did the same thing.....more prevalent in the mornings when it was cold. I got a BB tune and disengaged the AFM and now no more shudders/vibrations.