Hurricane Hummer Happening Help

[PARAGON]

I don't know if I have good luck or bad luck at our damn hummer happenings. It seems like every time we have one something goes wrong with my truck and today was no exception.

Not only did my truck throw a code and the check engine light come on but I had two distinct and disturbing sounds that we could not track to a cause and are not sure if they are related.

On the good luck side of things, a tech heard one of them and Hummer sales manager and my service advisor heard the other. One of the sounds was a sound like a belt slipping (the tech heard it) but all agreed it was not a belt because of the pitch and "speed" of the sound. The second one was a "clattering" sound like you were holding a stick in the fan. It made this sound doing an obstacle and when the traction control was working the front end. This sound obviously came from the front. My service advisor said it sounded like I was grinding something up, but I did have power to the wheels afterward. Also it replicated the sound at a low speed tight turn in 4low unlocked. Coincidentally, I have a front diff leak that can't be traced and we have the dye in it to try to find the source.

The code was "random cylinder misfire" and it occured previously but didn't set off the light. I paid for a damn fuel injection service because of this and it didn't solve the problem. My mileage has dropped to 9mpg in connection with this.

All of this and it was 3.5 hours one way with Rita flinging tornadoes at us. We averaged about 75mph on the way back and never heard a hiccup or had a problem.

Anybody run into any to similar "sounds."

[PARAGON]

I don't know if I have good luck or bad luck at our damn hummer happenings. It seems like every time we have one something goes wrong with my truck and today was no exception.

Not only did my truck throw a code and the check engine light come on but I had two distinct and disturbing sounds that we could not track to a cause and are not sure if they are related.

On the good luck side of things, a tech heard one of them and Hummer sales manager and my service advisor heard the other. One of the sounds was a sound like a belt slipping (the tech heard it) but all agreed it was not a belt because of the pitch and "speed" of the sound. The second one was a "clattering" sound like you were holding a stick in the fan. It made this sound doing an obstacle and when the traction control was working the front end. This sound obviously came from the front. My service advisor said it sounded like I was grinding something up, but I did have power to the wheels afterward. Also it replicated the sound at a low speed tight turn in 4low unlocked. Coincidentally, I have a front diff leak that can't be traced and we have the dye in it to try to find the source.

The code was "random cylinder misfire" and it occured previously but didn't set off the light. I paid for a damn fuel injection service because of this and it didn't solve the problem. My mileage has dropped to 9mpg in connection with this.

All of this and it was 3.5 hours one way with Rita flinging tornadoes at us. We averaged about 75mph on the way back and never heard a hiccup or had a problem.

Anybody run into any to similar "sounds."

[PARAGON]

Haven't heard anything yet. I had a meeting this morning and didn't get it in to the dealer until early afternoon.

I did some research on it myself though and gave the tech something to look for on on the squeal.

I've gone down to about 9mpg, had the squeal sound, rough idle and had the code about random cylinder misfire. I found some tech documents that suggest a bad alternator or power steering pump could create this. I guess a bearing or something going bad and creating extra drag would create this. Also, I have my RPMs increased to about 700 at idle with A/C on with the programmer. This is no longer working and RPMs are at about 500. So, I am wondering if I am on the right track there.

They are going to put it on the test track to see if they can get the rattle/grinding sound again. I am thinking a bearing in the front end.

[KenP]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">cylinder misfire </div></BLOCKQUOTE>
Maybe this will help.

[PARAGON]

I don't have anything really noticeable. I noticed the bad idle because of something sitting on the dash back when I had the truck apart. The truck accelerates normally and all that, doesn't backfire or misfire (noticeably) at higher rpm.

At the time I hadn't added it all up but in hindsight some of the symptoms might tie together. Each symptom in and of itself wasn't that big of deal but put them together and it might point to something more. I don't know. I do have a tendancy to overanalyze the crap out of things. I am still not sure how my tech takes it when I come to the shop and tell him what I think might be wrong and give him the tech document numbers to look up.

Question will be how they treat me on the warranty stuff. I am about 2 months out of the time period on my warranty but only have 24K miles on it. They have already stated that anything wrong with the front diff will be covered under the factory warranty since we know something was going on up there before.