2002 Aztek - Difficulty bolting EGR Line to rear exhaust manifold

smayfield

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2002 Aztek, GM 3400 motor... (rear head is currently off the engine)... I'm replacing the rear exhaust manifod and the EGR return line (old line was broken and rusted into the manifold). The new parts (confirmed they are the correct parts) behave like the thread pitch is different on the hole vs. the bolt on the EGR line. I can turn it easily by hand about 3/4 of a rotation before it binds... turning with a box wrench goes maybe another 1/4-1/2 rotation, but that's it. The line itself is very loose in the assembly and spins freely, even moving up and down... no way it's making a good seal. Anyone have any experience with these threads not being a match? I've inspected the threads on the exhaust manifold thinking there might be damage or something obstructing it, but they look fine. Threads on EGR bolt look fine as well. Been thinking of ways of rigging it up in case I can't get an answer, including stuffing the extra space with washers (worried about obstructing the flow) and maybe sealing it up with RTV.... any thoughts on that approach? Picture attached. Attempted to attach quick video but the forum doesn't allow it.
 

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Do you have a tap and die set to determine if the thread doesn't match?
 
Do you have a tap and die set to determine if the thread doesn't match?

Unfortunately not of that size. Though I might be able to take an imprint of the hole with a piece of paper and then match up the threads on the bolt... lemme try that and see what happens.
 
Unfortunately not of that size. Though I might be able to take an imprint of the hole with a piece of paper and then match up the threads on the bolt... lemme try that and see what happens.

Eyeballing it with the paper imprint (there was a bit of grease in the hole and it made a fine impression on the paper) against the bolt tells me they're not the same pitch :(
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double checked the parts, both say they fit this vehicle. The manifold is a Dorman 674-567, but the EGR tube is some random brand. I'm considering just ordering the Dorman EGR tube 598-202 and hoping it fits their manifold better/correctly. Their part looks identical to what I have. Hard to tell from pictures I know, but they have the same # of threads and seem to match up when I hold mine in front of the picture and get the scales right. Maybe a trip to my local auto parts store with the part I have and see if they'll let me compare it to whatever they recommend... yeah, I'll just do that... even if I just buy it locally, it's easier to return if it doesn't fit either. My inner redneck wants to just crank it on down and cross thread it.... the car has 253k miles on it, this is never coming off again anyway. But I'd like to do it right if I can :cool:
 
The Dorman part seems the way to go.
 
SOLUTION: I found the Dorman EGR tube at a local parts store and compared the threads. It is indeed threaded differently. However the local stores wanted $97 for the part, where Amazon has the same Dorman part for $38. I'd like to #ShopLocal and reward them for the help and having it today, but I can't justify paying more than a 100% markup on the part. They have to be more competitive than that. So the part is ordered on Amazon and I'm returning the no-name tube to get my $30 back for that.
 
SOLUTION: I found the Dorman EGR tube at a local parts store and compared the threads. It is indeed threaded differently. However the local stores wanted $97 for the part, where Amazon has the same Dorman part for $38. I'd like to #ShopLocal and reward them for the help and having it today, but I can't justify paying more than a 100% markup on the part. They have to be more competitive than that. So the part is ordered on Amazon and I'm returning the no-name tube to get my $30 back for that.

Just a final follow-up... the new Dorman EGR line threaded into the exhaust manifold perfectly.
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Thanks for the update, good to hear you got it fixed
 
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