Thoughts on 2.5 Dorman exhaust manifold

Tahdig_siah

Tahdig_siah

TJ Enthusiast
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Just placed an order for a DORMAN exhaust manifold. What do you all think of it? its for 2000 TJ 2.5L
Looks like Dorman was the only one that was around $100 and in stock. Do you know of a better brand that is in stock and doesn't cost more than 200-300 dollars ?
 
I have found the aftermarket 2.5 exhaust manifolds are all the same and fit terrible. You can grind and modify them to fit but they aren't a direct fit.

Some people go to a header but then you have to alter the head pipe.

You can find used ones here and there but I would be very cautious
 
It's
Tahdig_siah said:
Just placed an order for a DORMAN exhaust manifold. What do you all think of it? its for 2000 TJ 2.5L
Looks like Dorman was the only one that was around $100 and in stock. Do you know of a better brand that is in stock and doesn't cost more than 200-300 dollars ?
Click to expand...

It's possible you may have a problem with the thickness of the flange casting where it shares bolts for the intake manifold, I did and so did many others, they are mostly total crap and if it has the plugged O2 sensor (to fit YJ) they eventually crap out and leak badly. I received a used oem 2.5 manifold last week from ebay for $45 so I'm going back to stock.
 
TJ4Jim said:
It's


It's possible you may have a problem with the thickness of the flange casting where it shares bolts for the intake manifold, I did and so did many others, they are mostly total crap and if it has the plugged O2 sensor (to fit YJ) they eventually crap out and leak badly. I received a used oem 2.5 manifold last week from ebay for $45 so I'm going back to stock.
Click to expand...

It's not only that..the shield they install gets in the way and alot of times the casting of the manifold itself makes contact with the engine mount.

The last 2.5 engine I pulled had a newer aftermarket manifold installed and they left the very end bolts/nuts off..when you looked into thr hole you could only see a small portion of the threaded hole in the cylinder head. You would have never got a bolt started in there.
 
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Dorman really dropped the ball on the 2.5 manifold. You would probably(do not hold me to this) be better off with one of those $100 headers off of Ebay.
 
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I actually found the Dorman flange height to better match the intake manifold and mines lasted for years. The Mopar one I got from Wermopar lasted only 6 months and I had to grind down the exhaust flanges at the bolt locations about 1/8" to get a better match. It too had a crude cast "China" on the manifold.

Regardless of which you buy, you should do a little porting with a dremel to get the crude casting edges in the ports a little cleaner and hit the mounting hole locations with an angle grinder to get them a little closer to the same height as the intake. And most importantly, make sure you follow the revised Chrysler TSB that calls for less torque on the outside bolts (INCH-lbs, not foot lbs like the other bolts). I posted this on this forum years ago. Also, get rid of the carb pre-heat shields if this is going on a TJ - drill out the rivets.
 
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RaymondT said:
I actually found the Dorman flange height to better match the intake manifold and mines lasted for years. The Mopar one I got from Wermopar lasted only 6 months and I had to grind down the exhaust flanges at the bolt locations about 1/8" to get a better match. It too had a crude cast "China" on the manifold.

Regardless of which you buy, you should do a little porting with a dremel to get the crude casting edges in the ports a little cleaner and hit the mounting hole locations with an angle grinder to get them a little closer to the same height as the intake. And most importantly, make sure you follow the revised Chrysler TSB that calls for less torque on the outside bolts (INCH-lbs, not foot lbs like the other bolts). I posted this on this forum years ago. Also, get rid of the carb pre-heat shields if this is going on a TJ - drill out the rivets.
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Good to hear something positive, how are the o2 ports plugged.
 
Has anyone had any luck with one like this?

16B81A8C-AFFF-4534-B403-F00705C89E2D.png
 
How did fit for the time you had it? It’s either that or a used oem from broken down jeep. Chances are they used would probably last about the same I would guess.
 
RAC02 said:
How did fit for the time you had it? It’s either that or a used oem from broken down jeep. Chances are they used would probably last about the same I would guess.
Click to expand...

Had no issues at all with the fit, and actually much better than all the aftermarket cast crap which is why I put up with them cracking.
 
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