Doc's right about the 5cyl "idle-shake." My 5cyl Audi 5000 back in the 80's did the same thing as my H3. I notice it and my wife thinks I'm crazy when I ask her if she's felt it too. I wouldn't worry about it too much.

 

OK, with further info provided, I know what you are talking about. When you say it feels like it wants to stall I can tell you what it is doing. The key here is it does not stall, it just feels like a pause or a stumble for just a fleeting moment when slowing down.

The PCM is controling valve timing (VVT) when you are slowing under no load close to a stop to allow the engine to decrease its RPM to minimal idle as quickly as possible as a fuel saving measure. At the same time it is reducing the alternator power output also as a fuel saving measure unless you are running a whole bunch of accessories at that time. I think the program in the PCM goes just the tiniest bit too far, like right up to the edge of the engine stalling, before it sends the signal to again change ignition and VVT timing to get the motor to the proper at rest idle. That lag time between when the advance timing signal is sent, and takes effect, is what you feel.

Another example of the electrical time lag to illustrate what happens is the throttle lag. At a dead stop, at idle, quickly smash your foot all the way to the floor on the accelerator, you will notice that for a short time, maybe less than half a second, nothing happens, then the engine begins to throttle up rapidly to WOT. Take your foot off now! These trucks are fly by wire, no throttle cables, so the computor has to process what the accellerator pedal is calling for, then initiate several simultaneous commands, that then have to occur. This all happens super fast, but you can still feel the delay.

In other words, yep, it's normal, more so with the L52s (3.5L) engines. There may be a PCM update that can be flashed in at the dealer if you ever go in for other service that might make that a little less noticable.

 

mine does the exact same thing...not that its a good thing, but i'm glad i'm not the only one with these issues...i also noticed that the headlights dim as well when this happens...i'm goin in to the dealership on tuesday and will mention a pcm update so thanks Doc for the suggestion!

 

Same problem. Dealer says there is no update yet.

 

well damn, haha...guess pcmforless.com is lookin better and better!

 

Mine still does it, even after the PCMforless tune. I think it's just inherent in the I-5.....Like Doc said.

 

now we're getting somewhere....thanx DOC...I know I have OCD(obsessive compulsive disorder) but this is one of those subtle things that just seems to irritate me, and I'll check on the PCM update....hope this question was answered for some of you.

 

Hi Billyb....wow...I thought my H3 Adventure was the only one doing that....I have been experiencing this probably the last week or so. Thanks for asking the question and also glad Doc was able to shed some light on this. Anything help yours????

 

I have an 06 H3 and it does the same thing. When you are braking it seems as though it wants to stall. Having it checked out Tomorrow, I"ll let eceryong know what i find out>>>>