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2008 chevy trailblazer_lt
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78 Posts
Hello Everyone,

Forgive my redundancy, I have not read the entire threads as of yet. Just got back form mechanics shop and looks like Monday I will head to the GM dealer. From the first few pics I saw looks, like I have the identical crack. My 08 only has 68,000km, so just out of the 60k limit, though still under the 3years. Apparently the manifold is not covered under the emissions components warranty, unlike the cadiletic, muffler, sensors and so on. One dealership says yes they will look at it, two other immediately stated I was no longer covered.

Not happy! Only a year old and when she is cold, it sounds like a rough Harley, but as it warms up, I guess the metal expands and it gets quiet almost back to normal. After sitting for 20/30 minutes and cools off, it roars again. Surely this may have been a poor quality iron casting or a design flaw of some kind. No recall bulletins here in Canada for this or the Envoy, would anyone have seen any in the USA? Advise welcome.

Regards, CCI_TBLT
 

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2002
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93 Posts
I enjoy the club as well, damned.
Since a couple days i have this noises on the
Passenger side and it turns a little bit less when he
warms up, like other's told before.
Guess i have to go to a Dealership to get a quote,
i can't do it by myself.

Cheers
Frank
 

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2003 gmc envoy_slt_xl
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1 Posts
Another one

Cracked Manifold. Found replacement on gmpartsdirect.com for $134. Local mechanic will do labor for 225 + misc parts. Complaint filed with NHTSA. Here's a copy of their confirmation for your info.
Thank you for filing your safety-related complaint via our Web site or our Vehicle Safety
Hotline. The ODI Number listed below will be a direct link to your complaint as soon as it is ready to view. Please allow at least two business days for approval and processing before trying to view your complaint online. You will then be able to view it and search any associated documents.

Your Confirmation number (ODI Number) is: xxxxxxxxx

Your complaint information will be entered into the NHTSA
vehicle owner complaint database. NHTSA technical staff review this information to identify potential safety problems. While you may or may not be contacted by a NHTSA investigator to clarify the information submitted, all reports are reviewed and analyzed for potential defects trends. Also, the NHTSA complaint database provides valuable information to other consumers and to manufacturers.

If you have any questions regarding this complaint, please contact ODI:

By phone: 1-888-327-4236 8:00AM to 10:00PM Monday-Friday
TTY: 1-888-424-9153
Have your ODI Number available.
(Spanish-speaking operators available)

By e-mail: http://www-odi.nhtsa.dot.gov/contact.cfm
Indicate your ODI Number in the contact form.
 

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2002 gmc envoy_slt
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1,282 Posts
What do you expect the NHTSA to do??:confused:
A cracked manifold can, and has, as reported on this site before, melted the power steering reservoir with the hot exhaust gases escaping right towards the reservoir.

Loss of steering = enough for the NHTSA to get involved. Not to mention PS fluid on a scalding hot exhaust manifold (fire hazard).

If something happens or not with the NHTSA, who knows... but its worth reporting at least.
 

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2002 gmc envoy_slt
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1,282 Posts
Anything, if left unrepaired, can end up causing a safety concern. A cracked manifold often gives you plenty of warning that there is a problem. Just sayin'. Would be nice of them to cover the cost for those that have had the problem.
In order for the NHTSA to get involved, it has to involve loss of steering, loss of propulsion leading to loss of steering, loss of braking power, unexpected acceleration, and a few others that are crash related...

This may fall under the loss of steering... then again, methinks the NHTSA would've been involved a few years back if they really thought it was a issue :m2:
 

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2006 chevy trailblazer_ls
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123 Posts
yep been there done that, lucky for me my extended warrenty covered mine last fall.
I first noticed it when the vehicle was cold and put it in drive and I could here a small leak, once it warmed up it was hard to here but I lost a lot of power.
hen speaking with the dealer it seems to be typical since the engine bay is exposed to the tire well on the passenger side therefore allowing for cold air and water to fall onto the manifold this causing stress cracks and eventually it will have to be replaced.$875 at the dealer.
 

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2005 chevy trailblazer_lt_ext
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2 Posts
Cracked

Hello I am new to the Forum. I have a 2005 TB, 4.2 L that has 118000 miles. I have a cracked manifold and want to save my money for the SS headers. Does anyone know which temporary fix lasts the longest. I have read on other threads about the furnace cement. I also have seen on line a compound that permatex sells to fix cracks.:confused:
 

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2005 chevy trailblazer_ls
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132 Posts
Hello I am new to the Forum. I have a 2005 TB, 4.2 L that has 118000 miles. I have a cracked manifold and want to save my money for the SS headers. Does anyone know which temporary fix lasts the longest. I have read on other threads about the furnace cement. I also have seen on line a compound that permatex sells to fix cracks.:confused:

I tried two different kinds of cement......it only worked for a day or two.......but i had a huge crack in my manifold, it may work for a hairline fracture
 

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2004 chevy trailblazer_lt
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5 Posts
same crack in my 2004 trailblazer

I just finished replacing my exhaust manifold. It had almost exactly the same crack, front and back as the one pictured. I broke two bolts, the ones for cylinder 1.. Guess I was trying to hard at first and they snapped. I broke two drill bits and ended up purchasing some special carbide bits that work in a high speed dremel tool. They worked great, except I still could not get the bolts out with an extractor. So I ended up drilling them totally out and with those bits and retapping the holes. It was painfully slow work since I could only do half turns and had to pull the tap out often to clean.
If your interested in the bits they can be found at:
http://www.truebite.com/remove/index.htm

I moved the O2 sensor over to the replaced manifold. But Now I have a SES light, which turned out to be p0171 and p0172. AutoZone says this is either the MAP sensor or O2 sensor. since I just moved it, I am guessing something went wrong with it when I put it in.

I would like to see if this was just a clitch from the manifold change. but I don't know how to reset the codes. Is there a way to do this on a 2004 trailblazer?
 

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2002 chevy trailblazer_lt_ext
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249 Posts
Our 2mos.old has 145k and leak. I removed shield this morning too find 3 rear-most bolt heads gone...sprayed PB on all areas, warmed engine and was able to loosen front-most 3 bolts fairly well. Can't budge center 4-5 bolts using probably 70ft.lb.of muscle!:( so I sprayed it all up again. :( any advice...:undecided I'm thinking of spraying the PB for a day or 2?? what does that actually accomplish, does it "eat away" at the rust inbetween threads??
 

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2004 chevy trailblazer_lt
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5 Posts
exhaust removal.

I think the PB helps with the rust that sticks the head bolt to the manifold. It may help a little with the threads, but the biggest problem is the locktite on the bolts... It really locks them. I replaced all of my bolts with new ones, due to the older bolts pulled some of the tread out of the alumin. block.

I would recommend cleaning the threads , prior to re-installing. I used a kit from Autozone..

As to the stuck bolts.. if you can still run the engine, start it up and just warm the head a bit, not enough to also heat up the bolts much. Then try turning the bolts out 1/8th turn and then back, then 1/4 turn and back 1/4. This should loosen the locktite. Then do 1/4 and back 1/8th until you feel the bolt is loosening, then up it to 1/2 turn and back 1/8. until it is out. It is time consuming but this worked form me..
 

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2002 chevy trailblazer_lt_ext
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249 Posts
Thanks, I did work the front 3 out gingerly, rear 3 heads are missing, the center 5 won't budge. I do want to warm up the head before trying again but figure I'll let the PB do its thing for 6-12 hrs.before burning it off again. I guess I'm just eager to get the manifold off and continue forth.
 

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2005 chevy trailblazer_lt
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1 Posts
manifold

i get the wonderful task of replacing my manifold this week!! i hope i dont break any bolts!!! i will be soaking my bolts everyday this week until i recieve my manifold.
 

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2004 chevy trailblazer_ls
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1 Posts
Im just finishing up replacing my manifold like everybody else. same crack too. I got all my bolts out no problem, here is how it worked for me. Using an oxy/acet. torch not set hot enough to cut, but a nice sharp flame, direct it right on the head of the bolt for 10-20 seconds, until the tip of the bolt head held a slight color to it, not the whole head just the tip. Then let it cool completely!!!! The aluminum head sucks up the heat really fast so they cool quickly, but there is a fine line between hot enough and to much heat. Get it to hot and youll pull the threads out or warp the head. I heated and removed one bolt at a time, and used a 1/4" ratchet so i couldn't make to much torque. I had to heat a couple of them multiple times, but i think the key was to let the bolts cool. at first I tried to pull them out hot, and they wouldn't budge. Sat down had a beer, let them cool, couple light taps with a ball peen and they came out easily. Loosen half a turn, tighten 1/4 turn. Loosen 1 full turn, tighten a half turn. work them back and forth and they should come out. I cant stress enough to monitor the heat, be patient.
 

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2002 chevy trailblazer_lt_ext
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249 Posts
good job! Yea I was told one' could try the same thing but to squirt the bolt head with water which chases the heat back...a trick at the dealers to remove carriage bolts.
 

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2002 chevy trailblazer_ls
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16 Posts
I guess I am not alone. 02 125K i6 with a cracked manifold. I am about to tackle this job (replacing exhaust manifold, both gaskets and 11 bolts).

Parts:
88890560 exhaust manifold from gmparts.com
11609481 11 Bolts from dealer
Exhaust Manifold gasket from Advanced
Flange gasket from Advanced

I am taking EVERY precaution (heat, pb blaster, etc.) before I try and loosen these bolts, I don't want to break them off (especially the fronts). I've read all 8 pages of this thread as well as others.

Does anyone have any quick how-to instructions for replacing the exhaust manifold, preferably with pics? I saw the ones from roadie on this thread. Is the GM part 88890560 an exact replacement? are there any better ones out there?

Also, if I did break off some bolts and wanted to drive my TB to a shop, would it be OK to drive without the exhaust manifold?

Thanks... I can't believe these things are cracking like this... I will post pics of my repairs as soon as I have them.
 

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2008 chevy trailblazer_lt
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4 Posts
Add me to the club.. Wife's 08 with 55,000 miles started making a loud noise at startup. Took off the heat shield and I'll be damn...Big crack...
Ordered new manifold and gaskets. Sprayed the bolts two days ago with AeroKroil, which by the way is worth its weight in gold and much better than PB Blaster.
Pulled the power steering pump and the belt off to give me more wiggle room. Engine was completely cold and every bolt came out. Had two that were tight but was easy on them and they came out. The hardest thing was one of the nuts on the flange to the cat. It would not budge. Sprayed it with kroil again and 10 minutes later had it off... Everything went back smooth. Total job about 3 hours..
 

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2002 chevy trailblazer_ls
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16 Posts
I took off my heat shield, those 4 nuts were a bit tricky, on two of them the entire double threaded bolt came with it. I PB blasted them, but they are still a bit rusty. I had some trouble lifting the heat shield out. I disconnected the dip stick brace and the brace that secures the AC line. Unfortunately, I am still unable to remove the damn O2 sensor. It's really tight. :duh: I have the correct O2 sensor socket, but it just doesn't budge :duh::hissy::cry::cry: I am soaking it with PB blaster as we speak. I finally did get the heat shield off, but it was tight and I slightly bent it getting it out.

Surprisingly, NO visual cracks in the front of the exhaust manifold. :undecided In the middle near the O2 sensor it was a very blue, I suspect from trapping all that heat for the last 10 years :ugh: I visually inspected all 11 bolts, all were rusted pretty good and they looked fragile :bonk: I soaked the bolts as best I could while the engine was hot with PB blaster. I used the whole can over a two hour period of repeated applications.

With my air filter, intake and resonator off I removed my throttle body (why not?) and cleaned it as well. I started the car up to try and find the exhaust leak. I can hear it but I can't see it, definitely coming from the front close to cyl 1 and cyl 2. I suspect the gasket is leaking and/or the bolts from 1 and 2 are loose or pulled away from the head just enough to cause a leak... I can't wait until my tick tick tick noise goes away!

Tomorrow morning I am hitting the bolts with heat/cold/heat/cold and more penetrating oil before I start trying to loosen them.

Wish me luck... I really don't want to snap any of these bolt heads off. :no::no:

I'll post pics later on.
 
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