Hello everyone,

It has been months...maybe closer to 1 year since I last posted. Reason: I have been enjoying my H2 and other toys. Well, check out my story for some drama:

Beginning the first week of January I started the following repairs:

Dash cluster gauges: finally replaced stepper motors. Decided to replace background. Decided to replace plastic gauge indicators.

Driver's side door handle. Weak spring...wouldn't engage locking/unlocking mechanism. Could not use key to lock/unlock driver side door.

Oil pan gasket. Finally changed it. New synthetic oil. Spray painted the oil pan chrome. K&N oil filter.

New steering damper...went for OEM...Monroe/AC Delco with tapered end and lifetime warranty. Didn't use Bilstein like I had originally thought. The damper I removed was a Rancho with the "connector kit." It was completely beat/gone/toast!!

New gear box as my gear box was seeping/leaking/oil and figured it was time to change. I still have play in my steering wheel, but at least I got rid of 1 leak.

And last, but least, and perhaps the start of the fall.....

Removed stock exhaust manifolds due to looks, exhaust leak, and crazy heat. Replaced with some ceramic, titanium, black/grey powder coated JBA shorty headers.
During this work, I discovered 3 bolts were missing their head. Managed to remove the 1 stud that was sticking out of the engine block. The other 2, were left....couldn't get them out. Don't know how to weld. Don't want to pay someone to fix it...so, left them.

Now, I didn't connect exhaust pipes back to shorty headers. I did this b/c I was planning on ordering a new transmission in the coming weeks and thought I would save a step/time. Some disclosures: during the installation of new shorty headers, I started the H2 and moved the H2 WITHOUT the shorty headers on the block. I did this multiple times over the course of January...probably 4-5 times a week. H2 was loud as all get out and ran rich. I did this b/c I was trying to remove broken bolts over the course of a few weeks. Tried different things. Didn't always have time during the week. Weather was jacked. Etc, etc. Finally gave up. Bolted JBA headers to block and have been moving it around WITHOUT the exhaust pipes connected to the shorty headers.

I haven't driven the vehicle with the headers missing or with the exhaust disconnected. Simply started for 30 seconds to 120 seconds at a time. Just enough to move around the property/particularly out of the way. Dash lights: CEL, change oil light, ABS, TC. Not surprising since exhaust not properly connected.

Problems:
1. Battery dies within a few days.....like completely dead, won't turn over, nothing. Had to exchange with AutoZone several times.
2. H2 has experienced difficulty starting and staying turned on
3. Major problem now: engine won't turn over. Put a socket and breaker bar on crank pulley and I cannot turn the engine.

So, the short version: Help!!!

Things I will try over the course of the next few days:
1. Change battery for a new one
2. Check starter/replace
3. Check battery cable ends/connections
4. Remove torque converter dust cover and try to turn flywheel
5. Remove all 8 spark plugs and try #4 and crank pulley again
6. I don't know

Oil level has been checked multiple times, immediately after oil pan gasket change and once a week since. No oil puddles, dipstick is right on target. Truck has 209k miles on it. Original motor. Transmission is original, but rebuilt 1 time. The new transmission I was going to start installing today is still sitting in its shipping container.

Any idea/s, help, suggestion/s would be greatly appreciated. Very unexpected turn of events. Particularly a bummer b/c I spent $1,300 on a completely remanufactured tranny two weeks ago. Finally arrived last Thursday, the 1st. Now, I'm up a creek. Don't have any idea how the engine would have seized given what all I have done.

 

Generally a recipe for disaster if you ran the engine without any type of exhaust manifolds. Its easy to bend a valve that way. If your headers are still off, look into the exhaust ports and make sure a valve didn't bend or break. When the truck is running, the exhaust gases are extremely hot, having the manifold off allows cold air to be sucked in between compression cycles, leading to a bent valve or worse.

Continue with your idea of spinning the engine from the flywheel, its easy. Removing the plugs is not going to help, so unless you just want to change them its not needed.

Check the starter wires since you could have damaged them while installing the headers. That could be the cause of the dead battery too if you have shorted them somehow.

Best of luck

Tim

 

Engine is definitely seized!!!

Couldn't turn the engine via flywheel. Starter is 100%...checked it at AutoZone and it won't spin engine. Took spark plugs out....super black and burned out!!!

Drained the oil and voila.....nice silvery, grey, quasi brownish liquid came out. Oil filter was about 1/3 of the way full.

Initial assessment, spun a bearing. Several engine shops indicate the LQ4 does this often after 200k miles. Seems lame/bogus to me, but what can I do? My engine is shot!!!

 

I bet something with the oil pan replacement caused it to seize. Plugged up pick up tube, O ring damaged, silicone plugging up a passage or a number of things. An engine is not going to spin a bearing just because it has 200k on it, especially if it was fine before you did the work on it.

Whats your plan? Rebuild it, used motor, new crate motor?

 

 

I'd pull it out and take a look at it before spending anything on a new engine. If things are what you say, there can't be much damage. It might be as simple as a bent reluctor wheel for all you know. Atleast pull the pan where it sits and investigate.

200k is nothing on those engines. Lots of track cars out there with junk yard pulls and a big turbo making serious power without any issues.

Tim

 

Personally, if you are not going for performance parts as part of the rebuild and do not want to spend the large amount of time it will take to rebuild it yourself then I'd go with the reman with the warranty.

if you try to tackle a rebuild yourself you get zero warranty. Since it had very very little running your existing engine might also very well be rebuildable since you did not have an explosive failure that crushed and broke things internally. Might even be able to just flush it out, drop in new bearings and replace the gaskets that you have to and go. Not easy but it "could" be done with the engine still in place but if the crank journals got roughed up when the bearing failed then you will have to pull it regardless. The main (crank) bearings are not as easy but might also be doable in place.

Friend of mine did them on his 5.3 Silverado years back and I remember him saying is was a pain and lots of oil dripping in his face but spent about a hundred bucks and got another 100k out of it before he sold it.

I'd probably start by dropping the oil pan with it in place and taking a good close look. Will not cost anything to at least look and might save you a ton. If things are trashed then the engine needs to get pulled regardless. Of course safest bet is to just get the reman and go. Accessories are not a big deal since you can reuse the ones you have now. On replacement engine I would at minimum install new water pump, and pulley bearings.

 

 

 

Okay. Well if you want to have any chance at salvaging things on the cheap you first and foremost need to be careful and do NOT pry or beat on anything. Also do NOT attempt to start the engine in any way until something has been determined and that you can safely do so without damaging anything or causing further damage. There is a real possibility with only the few seconds of running that the engine might be able to be saved with out a huge expense.

You have 5 flat sections with bolt heads, those are your main bearing caps. Then you have the individual rods with 2 bolts on the end of each. Those are your rod bearing caps. Both have extremely tight tolerances and require specific amounts of torque when being installed. Everything must stay clean, oil is fine but introducing any sort of grit, dirt, etc can help to quickly destroy bearings.

Being in unfamiliar territory your really only have a few options. One, get it towed to an engine specialist. Two get or find someone who knows a good bit about this to come over for some beer and have them look. Three start spending a good number of hours on google looking at pictures, watching videos, and reading about rod and main bearings specifically in generation III and IV GM LS engines. It would be beneficial to have certain tools like a digital caliper to mic the journals to verify their dimensions, etc. Realistically, I'd have to reccomend asking around, maybe even dropping by a machine shop or two and explain things and potentially beg and offer to pay a guy to come by after work and at least take a peek at things.

I'm not certain on out Hummers but I know on a full size GM truck it is possible to replace the rod bearings and even the main bearings from underneath with the engine still in the vehicle. Its not exactly easy. It is also not exactly rocket science but it must be done right or you will have severe engine problems. You really need to get some plastigages which are extremely thin little plastic strips that help determine if bearings and in their proper tolerances. Once a rod or main cap is removed (never pry to get one off, a very very light tap with a plastic mallet if anything) the actual bearing and journal surfaces can be inspected. To remove the actual bearing it must be done from a specific direction.

It is really too much to try and write in something like this. You need to read and learn about this stuff to have any decent chance at possibly fixing it. There are literally tons of pictures of bearing surfaces online as well as pictures and even videos of engine teardowns which will detail removing bearing caps, bearings, inspecting the journals, using a plastigage, etc.