Hello all. Here is my first post I figured I would make it a doosy.

I am an ASE Master Technician, an Advanced Engine Performance Specialist and a factory trained BMW technician (though obviously no longer working in BMW land). I am currently working for a rental car company (not going to say who because I am not a "representative" of them and dont want any legal issues). We have in our fleet about 150 H3s. All bought en mass, and probably pretty close to sequential vin numbers. They all have a vin that says build date is '08 but most have the 4 digit manufacture date of late '07 with a few that I have seen in early '08. I have not seen them all yet, but being I am currently the only guy in the shop with a scan tool that can access GM I am getting to know them very well. The H3 are just starting to hit around 30K miles (from 26K-34K miles). I do have dealer support, but it involves calling and having them fax over information I need. I am posting here because I have found with my own vehicles that the place for information on them are websites like this. Many times the enthusiests have a better understanding of the vehicles then the dealerships. I figure if I share what I know I could very well get more information that could help me with my job.

I first came accross the issue with the heads and valves for these vehicles after seeing two H3 in one day with a misfire for cylinder number 4. Both vehicles responded to basic testing exactly the same. Swich coils, no change in misfire, switch plugs (which showed quite a bit of carbon) no change in misfire. Initially with the first H3 I figured it for an injector. I do not believe in coinsidence so after the second H3 I started searching online about P0304 and H3 and got this site.

Reading here gave me cause to dig deeper into the engines. I pulled off the upper intake and throttle body and looked down the lower intake manifold. On ever one of the H3 that I have done this on I see almost the exact same thing. Massive carbon tracking/gunking of the intake runners and lots of moisture. On the three I have actually pulled the lower intake manifold off on oil has dripped out of the bottom of the manifold and the pre-ignition chambers. If you haven't already caught on, this is a bad thing. I am ok with a LITTLE bit of oil, but not like that. Looking into the pre-ignition chambers you see a lot of carbon build up. I then pulled off the exhaust manifold to see that side. On the first H3 I did that to I saw a puddle in exhaust chamber #3. And quite a bit of carbon build up on that side as well, though mostly dryer then the intake side. At that point I pulled the valve cover off too see if anything jumped out at me there. Nope, the first time things looked normal.

So my conclusion as to the reason for the misfire is this: Not just one or two valve guide seals are leaking but every single one is leaking on both sides to some extent. This is causing oil contamination of the injectors, carbon build up on the valves and eventual misfires. If left unfixed the engine will start missing on every cylinder due to this problem. The vehicles are under warrenty. My recommendation to my boss is to replace the head. That is the course of action I am now pursuing on all the H3s that have this problem. The initial symtoms are either a misfire code (I have seen P0302-P0305, no P0301 yet) or a rough idle. I have also seen on two of them P0300, random multiple misfires and those two had lower intake manifolds that were just nasty.

Now for the really interesting part. It took 3 1/2 weeks to get the parts for the that first H3, in that time I have diagnosised 5 others needing this job done. The cylinder head is backordered so far that I have anywhere from 2 weeks to a month more before another head shows up.

So the head and all the parts show up this week and I get a chance to start on the job of replacing the head today. The new head is horible, where the camshafts are supposed to spin there are metal burs on all the edges and actual small bits of metal in the oil jurnals to be picked out. The replacement camshafts look like they were cut in half and welded back together. But on closer examination of the head still in the vehicle I can see that it is basicly the same condition. With the camshafts removed from the head in the vehicle you can see scoring from small particles being caught between the cam and the head. You can see burs still on the edges of the bearings. Particularly in the oil jurnals for the variable cam actuation on the exhaust cam shaft, though it is visable on each of the cam bearings (small point, but these are not cam bearing inserts but just cut and smothed out for the camshafts).

I do have a bunch of not so good pictures take on my cell phone of what I have mentioned above. I just have to find the software that will let me transfer it from my Razor to the computer so I can upload it.

I think that pretty much covers my current experiance with the H3 head and valve issues so far. Now question and answer part. I dont have any questions as of right now but please feel free to voice your own. If you have anything to add or a question to ask, please do so. I am sure someone can point something I missed out to me.

 

All the Atlas motors share the same head design, so your observations would not be limited to the I5.

Two words: Assembly Lube. [8D] Bad joke. There is a TSB on the injectors as well.

What do you think of the valve springs? No TSB on the springs per se, but I know there have been some bad ones.

You are using the term Head and Valve Issue in a different context than it started here. What I mean is it started here as a result of the TSB/extended warrantyof the 06 heads that were made with different valve seats than after the problem was diagnosed by GM (all Atlas Motors built post 3/31/06). I do not mean your observations are not valid, just relating to a different problem with the same troubled components.

BTW welcome to the forums, thank you for this DOOSY of a post .... and well you know this was gonna happen

[sm=ttiwwp.gif]

 

You know I get a silly grin every time I order assembly lube.


And this is why I posted. I had no idea about a TSB on the injectors. Like I said, I can get information I request from GM but I have to know the right questions. Still dont think it is an injector issue though.

I dont actually have any thoughts on the valve springs, the new head came with them installed. The valves seem to be seating correctly, compression was good across the engine.

From reading the posts about the older heads, it really does not look like the problem was fixed. It is still a valve seat/guide seal problem. Though I would love to see the original heads to see what has changed. The build of the one on the vehicle and the new one are similar, junk. Metal shavings left in oil journals and every wear point has sharp burs of metal. The one in the vehicle still shows signs of small metal particles wearing the bearings.

I am still working on figuring out what software to try to use to get my pictures from my old razr phone to the computer so I can upload them. As soon as I figure that, they will be uploaded.

 

Since you promissed pics.





Make / Models :
Model/Build Years:

HUMMER / H2
2003-2007


HUMMER / H3
2006-2007


SAAB / 9-7X
2005-2007


Service Bulletin Number :
030604030

NHTSA Item Number :
10021799

Summary Description :


VARIOUS DRIVEABILITY FUNCTIONS DUE TO CLOGGED FUEL INJECTORS, MIL/SES DTC'S P0171, P0172, P0174, P0300, P1174, P1175. *KB UPDATED 08-15-07. *KB

 

Random multiple misfires, lean and rich codes.

I have had the multiple misfire code, but only with conjunction with other symptoms that lead me away from just an injector problem. I will be keeping an eye out though.

Thank you!

Still working on the software needed.

 

Ok, here are some pics. Man does the razr camera suck.

First pic is the new head. It is very blury but you can see even with that the uneven edges. That is all the burs left after the machining.




This next pic is a piece of metal taken from the new head from the oil journal in the exhaust cam side.



I will try again on the rest of the pics I took to try to get clearer images.

 

Got a couple more pics.

Here is a piece of metal shaving stuck in a oil passage next to the valves. Just figured I should have a peak below before mounting the head.


And here it is out of the head.

 

Did you pull the Exhaust Cam Position actuator and look at the screens. Mine like a million others came apart and even though I replaced the actuator and flushed the oil replaced the filter I would assume there is still a trace of metal somewhere in the oil passages. I pulled the new actuator out just to double check after a few weeks and low and behold there were a couple more small chunks of metal from the original actuator. i am getting a very intermittent P0304 code but i did a lot of stuff lately and am not sure what I might have done to induce it. Green Cold air intake, E3 spark plugs, cleaned the throttle body, ran a can of Sea Foam in the tank. I replaced the plug and will swap the coil if it comes back. So far so good. Unfortunately I do have the 06 with the junk head on it right now. I guess I will upgrade if I have to. Anyone have a good place to get a rebuilt 07-up that will fit the 3.5 ??

 

Hello Folks,

This is my first post as a prospective new H3 Owner. I'm looking at purchasing a 2006 H3 with relatively low mileage (~70k).

There is currently an issue being worked regarding the PassLock system but assuming that gets resolved, I will proceed with consideration of this H3. My question relative to this thread is does this apply to the 2006 H3? Is there a test I should have the dealer perform prior to purchasing? Is it safe to assume the check engine light would be on and an associated code thrown if there was an issue?

I assume this is a separate issue from the PIP3935D that I have read about in other threads (valve intake leak due to valve seats not being properly hardened). Let me know if you think they are related issues.

Thanks in advance for your insights.