2008 Hummer H3 Alpha

[JPaul]

Temporary fix:

This is actually some pretty good tape, I was able to apply it while it was still raining and it stuck, I just squeegeed out the water as i put it down and it held just fine. We had a roll at work which is when I did this. I should pick up a roll or two and keep one in the Alpha.


When I got home from work I pulled out the carpet. I had checked it after lunch and the passenger side had a pool of water underneath and the foam rubber under the carpet was completely soaked. Fortunately since I've done it before pulling the carpet out only took about 15 minutes, then cleanup and putting the seats and trim back in maybe another 15 to 20 minutes. I put the Huskyliner mats back in, and it honestly doesn't look too bad since everything is black. I'm definitely considering just bedlining the floorpan and leaving the carpet out. I do take this off road and will be using it more and more for camping so it's just going to keep getting dirty. Either way the carpet will be out for a couple weeks while it dries and I consider my options.

 

[JPaul]

Made progress on the list of things to get done before Moab, plus I snuck in some extra work. First up was fixing some exhaust leaks. When I had the carpet in the noise from them wasn't bad at all really, but after pulling the carpet out I realized just how loud the ones on the passenger side were. I knew it was going to drive me nuts on the long drive to and from Moab so this became a priority repair.

I picked up some aluminum tape from Lowes (medium temp, 300 degrees) and used that to wrap around a couple of the welds that had some pinholes in them. I had some metal zip ties from Harbor Freight that I used to keep the tape from unraveling, just in case. Unfortunately that didn't seem to really help much, so I took another look and realized it was mostly coming from the exhaust clamp. I noticed that it wasn't really holding onto one of the pipes so I pulled it off. Turned out it had been installed backwards (its one of those clamps that has one side smaller than the other for slip fit joints), so I turned it around and reinstalled it and now the exhaust is much, much quieter. There are still a few more pinholes I'd like to fix, but one joint is right up against a heat shield clamp so I can't get any tape around it. I have some muffler patch compound I'm going to use, but I'll put that on another day, the worst of it is fixed now.

Next up I pulled the power supply for the rear dash camera out of the red H3 and installed it into the Alpha. This way it will power on automatically when the key is turned on, and I can ditch the cord running all the way through the Alpha from the aux power up front. It's wired into a power supply line for the rear wiper motor that comes on with the ignition.

This time I took the window surround off and filed a notch into it for the cable to pass through without being pinched. On the red H3 I didn't do this and I could tell the cable was starting to show signs of rubbing through the insulation.

 

[JPaul]

Once that was all done I checked my list of things to do and remembered that I had noticed at least one of the mounting bolts for my winch didn't look like I had tightened it down all the way, so I got back under there and sure enough it was loose. Good thing I didn't need to use it before now. I tightened it up and checked the others to make sure I had torqued them down all the way, they were all OK.

The last thing for the day was swapping the wheels and tires between the red H3 and the Alpha. On my red H3 I was running Goodyear Duratrac's in a 33" size (285/75R16), while the Alpha had 35" BFG KO2's (315/76R16). While the KO2's looked great on the Alpha, this is my daily driver more than anything so fuel economy is important to me (somewhat, let's not kid ourselves, it's a blood Hummer), as is strain on the drivetrain. Other factors include my trailer plans, I already lucked out on a set of matching Duratrac's for the trailer tires and since I'm planning on pulling a trailer pretty much any time we go camping (which is hopefully going to become more frequent now) it will be a lot easier for the engine and drivetrain to handle the strain with the 33" tires vs the 35" tires, especially since most of my trips will likely involve mountain passes to climb up and over. Also I have a full set of five of the Duratracs so I have a matching spare, while the spare I had on the Alpha with the KO2's was not matching, it was a mud terrain tire.

Another factor is that the I just prefer the way the H3 handles with 33" tires vs the 35" tires. When I took the Alpha out after putting the Duratracs on I noticed it felt lighter and a bit more sure. While I was swapping the tires around I stopped and weighed one of the Duratracs and one of the KO2's. The Duratracs came in at 75 pounds per wheel/tire while the KO2 came in at 92.2 pounds per wheel/tire. That's a difference of 17.2 pounds per tire, adding up to almost 69 extra pounds of unsprung weight and rotational mass. That's quite a bit really. Plus it's soooo much easier to manhandle the 33" Duratracs than the 35" KO2's, that extra 17 pounds plus the larger size makes them kind of a huge pain to work with.

I get that 35" tires are better for rock crawling and other things, and they really do look quite good on the H3 (and it's nice that you don't have to do a lift to fit them), but the reality is that I go rock crawling maybe once a year or so, twice if I get lucky. The rest of my time is spent driving to and from work and around town, and hopefully more frequently on dirt tracks going camping/overlanding. The 33" tires are perfect for me for that application.

Sorry for the poor shot, I just barely took it and I already had the Alpha in the garage for the night. I'm not pulling it out to get a better angle just for everyone else.


I still need to get the roof rack on and the CB antenna mounted, as well as look at rebuilding the spare front axles I have to make sure I've got some good spares for the trails. I'm getting down to the wire here, there is less than a week left before my Moab trip, and I'm probably going to be having to go into the office at night on Monday, Tuesday, and Wednesday to run updates on some of the web servers, so that will take up a lot of my spare time unfortunately. I also still need to go check over the popup trailer I'll be borrowing and make sure it's all ready to go for me. I'd really like to leave Friday afternoon after work if possible, but we'll see how it all goes.

 

[JPaul]

Almost forgot, one of the other things I did was to straighten the rear wiper arm. The stock setup is horrible, it basically cleans only half the rear window. Straightening it and re-clocking the arm allows it to clean a much more usable section of the rear window.

 

[BPD53]

It's nice to see your H3 Alpha. They don't seem to garner the respect they deserve. I modeled my truck after the H3 Alpha. Fixing the little things sure can add up, but your progress seems to be coming along really well. I'll be watching this thread and wish you luck.

 

[JPaul]

So it's been a bit since I updated this, mostly because I haven't really had time to do much on the truck thanks to work consuming far more of my time than I would like it to. Since the last post I hauled a pop-up camper down to Moab and spent a few days down there with my daughters and a bunch of the Hummer guys. It pulled the trailer really well so I was pretty happy with that.

Unfortunately skip forward to just a couple weeks ago or so and I discovered the Alpha has started making a new noise. This one sounded like a metallic scraping/rubbing in time with the engine speed. At first I thought maybe it was something in the transmission since that is where the noise seemed to be coming from, and lately I had been noticing that it seemed to be slipping in 1st and the 1st-2nd shift was a fair bit harder than it used to be. I tried checking the flexplate to see if that might be the issue, but from what I could tell it was fine. I ended up giving up and spent last Saturday pulling the transfer case and transmission to see if I could track down what the problem really is. Considering the Alpha has 160,000 miles on it I wasn't surprised it started having issues, I just wish it wasn't so soon after picking it up. But fortunately I still have my red base H3 so I have something to drive until I can get the Alpha fixed.

So after pulling the transmission (which is a terrible job when you don't have a post lift or a pit by the way and especially when you're doing it by yourself) I still couldn't determine where exactly the noise was coming from. The flex plate was perfectly fine, and when I spun the torque converter I didn't get any noise, and the transmission fluid looked nice and clean. So after some back and forth I tried starting the engine up without the transmission attached, and after putting the starter back on and hooking up the park/neutral switch to the harness I was able to start it, and lo and behold I heard the noise again. It was definitely the engine then. I put my mechanics stethoscope on the passenger side valve cover and this time I could hear a lifter ticking in sync with the scraping sound. Bummer.

So starting on Tuesday I think I began the process of pulling the engine out. I don't have a lot of free time right now thanks to my job, but I was able to get about an hour or so in each night except for tonight which I was able to get a few hours in. Everything is disconnected from the engine and the motor mount bolts are all cracked loose, so tomorrow I should be able to pull the block out and start tearing it down. Hopefully nothing was majorly damaged in the engine, particularly the block, crank, and rods. Otherwise I might be looking at just buying a re-manufactured engine. Either way I really hope I can get this all done and put back together in the next two to three weeks, since I have a trip to Colorado to go camping with my family at the very end of June, and I wanted to be able to bring the Alpha and my trailer to haul everything in rather than trying to pack it all in and on the truck. We'll see how it all goes, but considering I was able to pull the engine and transmission in a week's time I think I'll be ok, barring any major issues with the block and such.

 

[JPaul]

So here's the diagnosis. Lifter for cylinder 6 intake valve seems to have had something chew through it, probably a needle bearing, though I didn't notice any missing. So the lifter is shot as well as the camshaft.

Fortunately everything else looks OK. The pushrods look fine, as does the bore for the lifter. I pulled the rear 4 pistons out and the bearings all look fine and there is minimal scratching on the piston side walls. The cylinders don't seem to have any scratches in them that a hone wouldn't clean up, I couldn't catch anything with my fingernail.

All in all I think it's in great shape other than the lifter and the cam. I'm probably going to put a mild cam in to give it a little boost, seeing how I have to replace it anyway. New lifters and pushrods will be cheap insurance. I'm going to inspect the rocker arm that lifter mated with to make sure nothing went through it and chewed it up as well.

Hopefully I can get the rest of it torn apart, cleaned up, and then put back together in the next couple weeks. With how minimal the damage is I think it's definitely an attainable goal.

 

[superbuickguy]

what a motor looks like that had its oil changed with only synthetic and done every 5000 miles....

I always wondered what that noise was....

 

[JPaul]

Looks like the all too common DOD lifter failure. There are many kits available to delete the cylinder deactivation feature on these gen 4 LS engines. Other option might have been the cheap plastic lifter tray allowing the lifter to rotate.

On a positive note, you won't need to worry about this failure again after deleting the DOD components and re-tuning. Trick Flow and Brian Tooley Racing makes some decent cams and components for the smaller LS series.

The H3's didn't ever have DOD, they didn't even get VVT until 2010 which was the last year for the H3. The damage doesn't look like the lifter rotated, just slapping against the cam lobe.

I'm going to go with a Cam Motion stage 2 truck cam, I've heard good things about them. The rest of the rebuild is going to be more or less stock.

 

[superbuickguy]

The rest of the rebuild is going to be more or less stock.

I've said those words

 

[JPaul]

Dropped the block and heads off at the machinist this morning, there are a couple deeper scratches in cylinder 3 but he thinks they should come out with a honing. Everything else looks really good, he's going to check the rods, polish the crank journals, clean and check the heads and face them, and install new cam bearings for me. I should have everything back by Thursday which means I can hopefully get the parts I need in by Friday and get the engine assembled on Saturday. Then I can start getting it all put back together next week and hopefully buttoned up. Worst case I think would be the week after that, so three weeks from now. That puts me at a week before my Colorado trip which should be enough to do the break in procedure and make sure everything is looking good.

 

[JPaul]

I picked up the block, heads, crank, and rods/pistons this past Thursday. Everything checked out ok and needed minimal cleanup. The scratch really isn't too bad, and the pistons are OK so I'm going to be re-using them as well. Next time around I might spend the time and money to build up a 6.0/6.2 and a beefed up transmission, but I do not have the time or money to go all out like that right now.

I spent all of Saturday getting the rest of the parts cleaned up in preparation for assembly. Cleaning pistons is the worst, though the front cover was pretty tedious as well, followed by the oil pan. I sanded the outside of the oil pan to clean off the corrosion and make it look a bit nicer. I still need to tear the heads back apart and finish up the cleaning on them, there is still buildup on the intake ports I want to get rid of. I'm also replacing the seals and springs so they need to come apart anyway.

I haven't ordered the bulk of the parts just yet, I wanted to get everything cleaned up and checked out before I pulled the trigger on my somewhat large Summit order I have built up. Still a few more things to figure out and add to my cart, but I should be able to get the order in later today. Then everything should hopefully get here by Wednesday or so to allow me to start getting the engine assembled. The transmission is ordered, but apparently there wasn't one ready so it won't get here until the 20th at the latest, it might arrive a day or two before that. That puts me a lot closer to my trip that I was hoping for, but it can't be avoided.

Major upgrade is going to be a Comp Cams XFI Xtreme Truck Camshaft 54-450-11. Should give a decent bump in performance without killing my bottom end. I was torn between that one and one from Cam Motion, but the lead time for Cam Motion is longer than I have time for right now.

Pretty much everything else I'm replacing is either a wear part or needed for the cam replacement/upgrade. One upgrade I was considering was a trunnion kit to replace the factory needle bearings for the rockers, but after looking into it more it turns out the upgrade kits are wearing out within several thousand miles due to improper hardening of the shafts. I could go with a bushing based trunnion upgrade, but I need to do more research on the longevity of them so I'll just stick with the OEM bearings for now. I can always swap them out later by just pulling the ignition coils and removing the valve covers.

 

[JPaul]

Heads are torn apart and cleaned (thank goodness I picked up that c-clamp style spring compressor a few months ago on a whim for a couple bucks from a thrift shop, it's made this so much easier than using the puller type), lapped the exhaust valves to clean them up (intakes are fine, and exhausts really weren't too bad considering the mileage, but still), and parts should all arrive in the next couple days provided Summit can get my order out the door. Bearings and assembly grease are coming from Amazon, but my plastigage is coming from Summit. I think I still have some left from my last rebuild, I'm just not sure where the red one is, I know I've seen the green around and that might be all I need. We'll see. I might be able to start getting the block assembled in the next day or tow, but I need to clean up the garage from tearing down and cleaning everything before I can start final cleaning and assembly of everything.

I'm still shooting for fully assembled by the end of day Saturday, but I have something in the afternoon onSaturday that's going to take up a good 4 hours of my time, so hopefully that doesn't set me back too much.

 

[JPaul]

A few developments. The transmission has shipped and will be here the 18th, so that's good. And Summit shipped my order today and it is supposed to get here tomorrow. Unfortunately the head gasket set I ordered off Amazon came today and it turns out it's the wrong one. The frustrating part is I used FelPro's lookup tool to find the right part number and it turns out they are wrong. They have the 2008 and 2009 model year H3's with the 5.3L using HS 26190 PT-2 and 2010 using HS 26190 PT-4, but they should all be using HS 26190 PT-4 which is for the Gen IV LS engines. HS 26190 PT-2 is for the Gen III LS engines and none of the H3's used those. Not sure why they did this, but it's pretty darn inconvenient.

The main difference between the two is the Gen III's didn't have the bosses for the AFM (DOD) and the knock sensors were located in the valley. The Gen IV's have bosses for AFM (DOD) but since the H3's didn't use this they used a different valley plate the blocked off the oil flow from those, and the knock sensors were moved to the sides of the engine, as well as several other differences from the Gen III's. So the gaskets for the valley cover are completely wrong in the PT-2 kit for the H3. If I can find some contact info for them I'll eventually reach out and try to get them to fix this. I should have paid closer attention to the picture of what was coming in the kit, but I never trust those anyway, and you'd think that they'd have gotten it right in the first place, especially after so much time since hte H3 Alpha's were released. I doubt I'm the first one to have this problem.

Thankfully Amazon had the PT-4 kit in stock and Prime so it will get here on Friday. I can at least get the bottom end all put together in the mean time and then Friday and Saturday finish off the top end. I'll still need to order pushrods after I verify the length I need, but those can be added last so it won't hold me up much.

 

[JPaul]

Checked clearances on the crankshaft last night, everything was still within production specs so I went ahead and did the final clean of the crank and journals and installed it. Next up is the camshaft and rods/pistons. I should be able to get those all checked and installed tonight, and if I'm lucky and have enough time I can get the entire short block assembled tonight. I was stressing out about my timeline before, but I feel a lot better now after being able to get the crank installed, even if I was up till midnight doing it. Even if I can't get the short block done tonight, I'll be well on my way to hitting my goal of getting it all back together by end of Saturday. Then it will be ordering pushrods and then next week will be re-installation.