So i was driving the other day and the h2 did something wierd. Not really sure how best to describe it but the best way i can think of is it feels similar to when you run over those little ruts in the median off the highway. You get that quick vibration feeling from the tires hitting the bumps.

So what happens is between 50-60 mph with minor acceleration around 1500 rpms or so the hummer does this brief stuttering. My first thought was that maybe the transmission is slipping but there doesnt seem to be any of the typical delay during shifting that is associated with a slipping transmission.

ANyone else run across this or have any thoughts?

 

sounds like torque converter issue

 

Coil pack failing.

 

I agree with AK47 Sounds like a misfire, coil, plugs or wires or even an injector.

 

Its the throttle position sensor most likely.. been there same scenario many times..it wont always throw a code either. check it with an ohm meter. I think almost every vehicle ive had- had to replace..usually that or map sensor. Just changed a map sensor the other day. vehicle would shake a stutter until 2nd gear..
throttle position sensor tps are normally intermittent, like a gummed up o bad spot in a carb..let off the gas it smoothes out, hit that bad spot again in the resistor and it shakes/sputters/vibrates..
good luck..
Merry Christmas
99

 

doubt it, have had bad TP sensors on LS engines also and what you described isn't what I have seen but I do agree they rarely set SES light . Usually the largest malfunction is they appear to roll forever when let say on back road & they make the trans shifts very erratic from very hard late shifts to early shifts were it lugs bad because it's to high of gear for conditions. If it were a map sensor the truck wouldn't exhibit any issues when it's cold because it won't accept input from it till its at the full operating temp, I have seen & heard of dozens of replaced map sensors and bet none of them were faulty inexperienced mechanics ( not calling you inexperienced)like to replace them when they can't figure out the problem and they start throwing parts at in hope it cures the problem.

 

preliminary diagnosis by the dealership is the clutch in the torque converter is going bad. Does anyone know if the torque converter can be rebuilt or do i need to buy a complete unit? If i need a whole unit does anyone know of a good source for parts?

 

I would say torque converter it shuddering in lock up at a given RPM .
that’s what happens on other Gm vehicles anyway , im new to the Hummer so it maybe something else

 

Opps sorry , i guess i should have read the rest of the thread before replying .
can they be rebuilt , yes .
but for the exspense i would just get a new one . while your at it , spend the money and do an up grade

 

what is the upgrade?