• Welcome to H4O! For a reduced ad experience, please login or register with the forum.

Major help needed for my H3 and my sanity!

Mizery13

Member
Messages
14
Location
Orlando
Hello kind peeps,

My H3 ran really well for the first three weeks. Life was good. I had my dream truck and was a happy guy. The family was comfortable in it and it was all I wanted for off road as well as a pleasure to drive, to and from work. This is where the story takes a turn and my life took some nasty changes. He and I went for lunch and upon returning, he received a call that he was to cancel my contract as the company had decided to go with a national service provider. This was my only source of income. I just spent all of my savings and was now out of work. Oh well, at least I had my H3 right?

I jumped in the Hummer and headed out for lunch last week. We had lunch and I climbed in to return home. Problem begins: As soon as I pulled to the stop sign in the parking lot to leave the luncheon, the truck began to drop off in idle and act very strange. Every time I stopped at a light the truck stumbled and acted as if it was going to stall. I got it home and stayed home for the rest of the day. After that day, sometimes when I would start the truck, it was idling strangely. Other times, it would run as smooth as silk. I used it very sparingly and just kind of hoped that it was maybe some bad fuel. I picked up some Techron fuel additive and hoped it would resolve my issue. It did not.

I had no other issues except for the occasional strange idle. He called the other night and asked me to come over to his place. I started the truck and it all began. The truck ran horribly. It was stumbling, missing and I thought I may not even make the five mile trip to his house. I did make it there but it seemed on 4 cylinders. He has a code scanner there so we plugged it in and got some codes indicating a misfire in the #1 cylinder. It smelled very rich and just wouldn't clean out at any RPM. I stayed for about an hour and decided to head home before dark. Oddly, the truck seemed to clear and run real well all the way back. No misfires or stumbling idle.

So I began reading the forums and trying to see what I may be up against to get my beloved H3 back to normal. From the cylinder head nightmare stories, to MAF cleaning to throttle body to bad plugs to bad coil/s to computer. Now, I am broke and jobless and have a truck that won't run so my stress level is reaching MAX. I went to the auto parts store on Saturday and got the MAF cleaner. I also got the throttle body cleaner. I did get quite a bit of crud from the TB but nothing compared to some pics I have seen in my research. I put it all back together and went for a 20 min drive. It ran great. Nice and smooth and normal. I went back out a few hours later, started it and realized, I gained nothing. It was struggling to go around the block. I came home, frustrated and parked it. I went out Sunday morning, started the truck and it was perfect again. I drove it for about a half hour with no stumbles whatsoever. Had I fixed it and it just needed time to sit? Did I not let the MAF dry completely and now, after sitting overnight she was all good again?

Well, NO...I went out a couple of hours later and the truck would barely run. It smelled horribly rich, stumbled and didn't want to run at all. The check engine light would flash, then come on and stay on. I checked the codes again and sure enough, misfire in #1 cylinder. What have I gotten myself into here? Why does it sometimes start and run perfectly then later the same day, not want to run at all? I have limited funds and no mechanics that I really trust to not try to get the remainder of change I have left in my pocket. I know that nobody can completely diagnose this from my description but I am looking for a starting point. I have to get this truck to run so I can work. I have a $16K truck in my driveway that looks great but I have lost all faith in.

I am hoping for any advice from you as to what you may think this could be. I need a place to start. I need help and I need it badly. Have any of you had this experience? If electrical, why would it occasionally run perfect and later the day, not want to run at all? I would so appreciate any ideas and advice you folks can share with me. I live in Central Florida, just North of Orlando. Should I just try to limp it to a buyer and sell it "as" is for a huge loss? I love my truck but I need transportation and I need it fast. My family depends on me for transportation and for me to earn a paycheck. I am sorry for rambling on for so long but I just am at the end of my rope. If you can advise me as to what you think, what you may do or have done, I would be very thankful. I am at the point of wishing my Durango was still in the driveway and my hard earned money was still just in savings. What a bittersweet month it has been. From incredible excitement about my new Hummer to not knowing how I will get to work to having spent the majority of my savings.

Thanks so much for reading this and for any ideas you may have as to what I can do and what may have happened to my truck while just sitting in the driveway. I have only gotten to enjoy 500 miles since I bought it and hope we can come up with a remedy so I can fix it, keep it and enjoy it for a long time to come.

My sincerest gratitude,

Dave

Hummer pics 129.jpgHummer pics 086.jpg
 
Last edited:

Sethmark

Well-Known Member
Messages
230
Location
SC
Move the plug and coil pack from cylinder 1 to 2. Move cylinder 2 to 1. If the misfire moves you have your answer.
 

alrock

El Diablo
Staff member
Messages
10,664
Location
Scottsdale
Sethmark is right on the mark . . . BTW, I removed your duplicate post. I think you'll get better answers with just one thread on the subject.

I suspect if the misfire doesn't follow the plug and coil pack then you could be facing the head issue.
 

Mizery13

Member
Messages
14
Location
Orlando
I just didn't see how the coil pack would be intermittent. Your answer is certainly logical. I don't know enough about the coil pack deal to know if they can work perfectly and then, fail but I will certainly try this and let you know. Thanks.
 

Xlr8n

Well-Known Member
Messages
140
Location
Midwest
I just didn't see how the coil pack would be intermittent. Your answer is certainly logical. I don't know enough about the coil pack deal to know if they can work perfectly and then, fail but I will certainly try this and let you know. Thanks.

On the other hand, I wouldn't expect the head issue to be intermittent either. If you have a head leak, seems it would get progressively worse, not off and on.
 

alrock

El Diablo
Staff member
Messages
10,664
Location
Scottsdale
My head issue was intermittent, or perhaps better phrased it was developing. It didn't always appears but I also never saw symptoms like yours. The head issue manifests itself in different ways, which supports both theories: it could be the head issue, or it might not be it.

ABN, it was a great answer you posted!
 

JGBB04

Well-Known Member
Messages
520
Location
Tampa Bay
#1 quit trying to keep up w/ the jones'. Now on to your engine problem, my guess as already mentioned would be bad coil or spark plug. The head issue was usually a 06-07 problem with the 3.5 motor. I've similar symptoms with my work truck(07 expolder) & both times it was a bad coil.

Ps welcome from bradentucky
 
Last edited:

Sethmark

Well-Known Member
Messages
230
Location
SC
Coil packs fail. And they don't have to fail catastrophically.... They can do so intermittently. Their job is to store energy and then expel it onto the spark plug when it's it turn. A single cylinder misfire is almost always in the coil, wire or plug. And in an already unbalanced 5 cylinder, inline motor a misfire feels horrid.

My money is there. I would expect overheating and fluid mixing on a bad head.
 

4speedfunk

Well-Known Member
Messages
4,250
Location
Tardville
Human nature tends to always think the worse. Try the coil pak/plug swap. If you still have problems...try a compression check. This is an old-school procedure that will give you some very valuable info without costing money or tearing anything apart. If you pass a compression check...its most certainly something minor.

On the other hand...if you have one cylinder that is reading far lower compression than the others...get out your wallet!
 

chad

Well-Known Member
Messages
545
Location
florida
if you need parts call wayne auto parts located in ohio, they ship, someone posted them and i called them up, they got good prices on stuff.Phone Numbers:

Toll Free: 800-545-7809 800-545-7809
Local: 330-343-9622 330-343-9622
Fax: 330-343-1114


 

ArtHummer

Well-Known Member
Messages
1,220
Location
Gaithersburg/MD
+1 on the coils.
It could be that water got in to the coil when seller was cleaning the engine bay.
The best theory is start small and then go big stuff. It will not cost you a penny to check the plugs and coils. And most likely the issue is there.
 

Mizery13

Member
Messages
14
Location
Orlando
Thanks to all for the input. There is some peace of mind in hoping it's a coil/plug vs the head. My apologies in advance for having posted this issue in more than one forum. First off, I am new here and secondly, I was desperate to get some advice from those of you that know. It won't happen again.
 

mudbug

trail blazer
Messages
232
Location
Brighton,Co
I had almost the same problem with my h2. I filled up with fuel and drove for about an hour at 70 to75mph and once I got into El Paso I pulled up at a red light it started idling rough and hesitated at tack off and ran poorly down the road then it cleared up and ran fine. Stopped at the hotel to get a room and left to go visit a friend the 2 started up fine and ran good going down the road for 10min and it started acting up again. Stopped and fueled up, thought I was running out of fuel, left the gas station and ran fine for 2to3 lights and it started acting up again. I made it to my friends house and we left to go eat the 2 ran fine again. We left the restaurant and the 2 started acting up so I stopped by the auto parts store and picked up some water remover and put that in the tank and that fixed the problem. So you might have bad fuel.
 

stix

Active Member
Messages
43
Location
Orlando, Fl
Would also check your battery leads and all grounds. I had a similar issue that was fixed when the main ground on the frame to the right of the battery was tightened back up after stereo install.
 

Mizery13

Member
Messages
14
Location
Orlando
Update:

Stated the truck this morning and it ran rough. Bad idle, rich smelling and breaking up when incresing PRMs. Shut it off and left for the day. Got home at 5PM and started the truck. It ran great so I jumped in and drove for a good 30 min. Got back, shut it off for 5 min and started it again. It ran great so I went around the block a few times just to be sure. No problems. Now, if the normal holds true, I will try it again in about 45 min to an hour and fully expect that it will again be running as if a cylinder was removed. I will update later after the trial. Also, when running normally, no codes and no CEL. If it happens as I suspect, I will rotate coils tomorrow to see if the code follows the coil and go from there.
 

Mizery13

Member
Messages
14
Location
Orlando
Would also check your battery leads and all grounds. I had a similar issue that was fixed when the main ground on the frame to the right of the battery was tightened back up after stereo install.

Interesting, I will check that also, thanks.
 

Happy Hummer

Well-Known Member
Messages
1,460
Location
Wisconsin
Top