I found my leak. Looks to be leaking from the farthest 2 exhaust flanges. The 5th is missing one bolt altogether, and the 6th has a good gap between the manifold and the block. This isn't a fix I really want to try to tackle, and I don't think it's a wise idea to try and tighten it either. Guess ill live with the noise until it gets really bad. At least it's not a crack...yet. Would anyone recommend an exhaust weld paste to bead around the gasket?
As a retired GM Engineer/Technician, I would definitely NOT Recommend ANY type of PASTE or GOO to repair this problem. :weird:
It will NOT last and could very likely damage the O2 sensors and or the Catalyst.:duh:
My advice ... JUST DON'T DO IT. Spend the time or money to have it fixed properly or just trade it in.:m2:
Hey guys, I have a 2003 Trailblazer with 203k miles. I am looking for some expertise. I have had a slight exhaust leak for about 5,000 miles or so. I took the car on a long trip this weekend and while cruising at 70 mph, all of sudden the exhaust leak got VERY loud. It almost sounds like it is straight pipe. The sound is definitely coming from under the hood. The manifold is still attached to the down pipe. It appears that I did not lose any power.
I haven't taken the heat shield off yet to take a look for myself. I dont want to spend $500 at a shop to have it fixed. I am decent with my hands (not a ton of car experience though). Any advice on this?
Sounds like it may have cracked the Manifold.
The repair isn't too awfully difficult if all goes well.
But at 203K all going well could be a problem.
First before attempting this remove the heat shield and get a better look at the problem.
If it is indeed cracked replacements are available from the Dealer or Ebay (choose a reputable seller).
If replacing the manifold also be prepared to have one or more broken studs, usually in the most inconvenient location. I replaced all of the studs and bolts (about $50.00 at Dealer) If it's out already don't cheap out on the fasteners I'm told there was a design change from the Original bolts.
New gasket (~$15.00) - Easy-outs for broken bolts - drill and tap and Helicoils for the broken ones.
Did mine in about 6hrs in my home garage. Your mileage may vary
It might and it's always a good Idea - but "heat" and SLOW back/forth when walking out will help as well. Remember to expect broken bolts and right at the Head surface
Aluminum heads and steel bolts aren't highly compatible "Electrolysis" isn't your friend.
If you try it - Go slow when bringing them out & good luck.
You're right and i apologize for this. I had a hell of a time even getting the heat shield off (with limited tools) due to rust. I brought it to another shop that I trusted and it turned out to be a blown out donut gasket where the manifold attaches to the downpipe. It cost me 90 bucks to have him fix it. It was nice to hear the car sound like new again. I almost couldn't believe it was running, it was so quiet!
Hmmm... I have coworkers that also have gmt-360's. Mine sounds great and I have boo-koo power, but it's slightly louder than the others in the parking lot. I'll inspect my manifold soon.... I work a lot so soon might be a couple weeks. It's not annoying or getting louder... kinda sounds tough actually, but if something isn't right and could cause other issues I try to fix it asap.
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