DIY Exhaust manifold replacement

[AlaskaDan]

On an earlier thread I listed some options. I went with the MagnaFlow Exhaust 51882, $422.54, free shipping, arrived at my door in 3 days via FedEx, ordered through Amazon. To remove start underneath. The 3 nuts are the worse. Impact driver would be great. I had none. I removed the front drive shaft to get more room. Also remove rear exhaust from hanger to get more movement. At top removeAirDoc, remove tranny dip, 4 bolts for heat shield, 2 bolts from that cover thing(what is this thing for? I replaced it a while back, it cracked) Removed 9, 1/2 inch bolts. Were fairly easy, none broke. Remove manifold. Insert new, torque to 15 foot lbs. Don't install o2 sensor till you got manifold in. I did manage to remove and reuse old one.

 

[SolidusJ]

Great job man!!! You might be able to get some cash back for the guts in the catalytic converter.[h=1][/h]

 

[alrock]

Nice! That's not a job I'm looking forward to undertaking, but I need to do at some point. Now, if Reloader does the heavy work for me that's a different story

 

[hockeymanam]

Wow this thread was meant to be!!! My manifold just busted apart yesterday on the trail!!!

 

[4speedfunk]

Nice. Remember....

 

[hockeymanam]

so i jumped on amazon and i found a magnaflow for a 06 h3 looks the same as the one you posted
http://www.amazon.com/MagnaFlow-Exh...&newCar=1&s=automotive&vehicleType=automotive
It has a different part number but i can see no difference other than its $10 cheaper

 

[hockeymanam]

well did some more research and the one you ordered is made to oem grade and the one i found has less precious metals in it... i guess i should go oem grade

 

[telemike]

How is the quality of the magnaflow? I may need one sometime soon since my manifold is cracked and sputters

 

[telemike]

This is a little pricey: http://www.mesablackworks.com/hummer,h3,headers

 

[telemike]

How long did it take you to change out? Was it relatively easy or hard? How do you like the magnaflow?

 

[hockeymanam]

yea what he said^^^ im about to tackle this project this weekend. any pointers?

 

[telemike]

Did you have to move the AC lines out of the way? I could not see an easy way to move them.

 

[telemike]

The Maganflow for my 2007 is $700+ as compared to the 3.5 2006 header.

I did find the Walker 16481 for $413 from rockauto.com

 

[hockeymanam]

On my 3.5 i was able to get a wrench in and around them. it was the bolt at the front of the engine on the bottom that had me cussing. the hardest part By far is the three bolts below the c.a.t. attached the the exhaust.

 

[06 H3]

which one did you use hockeyman?

 

[hockeymanam]

I ordered the magnaflow oem replacement. i ordered it tuesday and still waiting. as soon as i get i will post it up

 

[telemike]

If you can take some pics as you take out and install that would be great! I am wondering about the AC or heating lines that go thru the firewall aboe the manifold. Do they need to be disconnected or not?

 

[hockeymanam]

so the ac line are not a problem they are flexible enough that you can get the header around them with a little elbow grease. So it showed up yesterday and i went to install it and i got 8 out of 9 header bolts to line up, tell me how 8 line up an one doesnt... idk so then i took a break and went underneath to hook the exhaust to the bottom of the CAT. well the flange on the exhaust that slides over the three new bolt of the CAT would not slide over all three. I do not know if the three bolt are just slightly further apart or what but it was not happening. A normal fix would be to just bore out the wholes a little more and i see that being an easy fix. I am in colelge with out all my tools with me so either my dad is coming to come up with the compressor or im going to have to take it to a shop! which is a worst case scenario cause i love doing things my self but i will keep you updated

 

[telemike]

Oh bummer.

Sent from my XT907 using Tapatalk 4

 

[alrock]

Thanks for the install update. Curious to see what it takes to finish it.

 

[AlaskaDan]

Update with my new exhaust manifold. Getting 2 more miles per gallon! On install did not have to remove any lines. All 9 bolts were easy to get out. But need a deep well and swivel 1/2 inch and several different size extensions. The hardest part was getting the 3 bolts on the bottom removed. If you have an impact they should be no problem. Everything lined up with mine. As for the bottom 3 bolts not lining up, you sure the collar that the 3 bolts slide into in not warped? Mine was slighty and need to take several wacks to get the bolts in. Likewise, when taking apart It was difficult to get the collar off after the bolts were removed.

 

[AlaskaDan]

4speed, Thanks for the memory. I sure do miss you guys and off roading with you. I have not met up with a group here in New Mexico. I went out with a jeep club a couple times but it is not the same. They go out more for site seeing. There was a big mud hole off the trail and I went barreling through it. No one else did and I got the evil eye. I have not gone with them again.

 

[cbetts]

Any noticeable power increase? I remember gaining some bottom end power by just going to a Gibson cat-back exhaust.

 

[hockeymanam]

so lets say i wrap this up and still cant get all 9 bolts in just 8. would that be okay or no?

 

[AlaskaDan]

NO!! You need all 9 bolts! That last bolt ( 4th to left from center) you need a swivel socket with a 6 inch extension. The torque wrench handle will be between the two A/C hoses. Very cramped and takes patiences and you have to crawl into the engine bay. You do have a think blanket on the fender? I actually got a bruise across my belly due to the black hard rubber hood contact thinging. It still hurts. If your swivel socket does not make good contact on the hex head, try lightly tapping it in. It will be stuck when you tighten it up, so pull the extension off and use it to lightly tap on the swivel to remove the socket. It will be pinched by the manifold tube. Or you have too beefing of a swivel socket. Take your swivel socket to walmart/auto zone/napa... and find a shorter length, less beefing, swivel socket. And of course you are using a torque wrench set at 15 FOOT/LBS. AND do the rotation 3 times. Start at center bolt, then go 1 right, then go 1 left of center, then go 2nd right of center, then 2nd left of center..... And you did put lock tight on the bolts.