Dorman exhaust manifold cracked in 3 months.
- Thread starter Colorado4
- Start date
Cousin Clyde
Hooked
I imagine Dorman would replace it for free. They seem pretty reputable. Maybe had a QC issue with a bad casting. Is it a cast part?
monstrousmac
Caught the Bug
So I found a way to prevent it. At least it worked for me and I know it sounds crazy but hear me out. I have changed 3 out on my 2010 JKU, I went to a local exhaust shop here in Tucson AZ. The technician who is a friend of mine installed a new one, I believe he got it from NAPA, so I am unsure of the brand, but he took of the installed heat sheild that comes attached. He said he has found when you remove the heat sheild for what ever reason they dont seem to crack. My 4th one has been on for the last 65K miles and still has not cracked, knock on wood.
JimLee
Hooked
Unfortunately, Doorman products in my experience are hit or miss in quality. I've woked at a few of the auto part retailers (part time while I was in the military and stationed stateside) and Doorman products were almost always one of our highest return items. I'd love to go to their aluminum oil cooler on my JL, but worry that might actually be introducing a problem.
Cousin Clyde
Hooked
Interesting. Appreciate the experience. I have no previous experience with them. I’m hoping for the best on this damn oil filter housing.
In steel construction equipment, I’ve definitely handed some brand new equipment back to my vendors because I can see visual impurities in castings. New one comes, looks clean, no problems.
Sounds like this problem may also be inherent to the ol 3.8 regardless of manifold manufacturer???
JimLee
Hooked
Yea, the 3.8 seems to have a rep for eating those manifolds. I don't think all the Doorman stuff is bad, but form what Ive heard they farm out most of their manufacturing to many places, and they make a million things, thats probably why the quality doesn't seem very consistent across their products. Let us know about the oil filter housing, I'm still interested in the one they make for the 3.6, luckily I haven't been forced to make that decision yet
jeeeep
Hooked
on my 2010 JKU I've used dorman, crown, omix-ada all cast iron, all have cracked.
I've driven the JKU about 500 miles since they were last replaced, and the driver side is already cracked.
Mopar has discontinued the manifolds for 2007-2011 3.8L
Thinking about spending the extra money for ductile iron manifolds from AFE
I've driven the JKU about 500 miles since they were last replaced, and the driver side is already cracked.
Mopar has discontinued the manifolds for 2007-2011 3.8L
Thinking about spending the extra money for ductile iron manifolds from AFE
I thought of stainless but heat tends to melt plug wires. I saw the dorman instruction sheet and it says "correct mounting surface runout prior to installation or new manifold cracking will recur." I suspect mechanic thought it was a normal replacement and did not bother correcting surface as instructions said. That's prob a clue.
jeeeep
Hooked
I tried a set of Gibson headers, aside from melted wires which I replaced and wrapped with heat sleeves, my JKU never ran smooth and removed them after 200 miles. I figured that was ample time for the relearn curve.
Bierpower
Hooked
Anybody have any experience with these?
afepower.com
BladeRunner Ported Ductile Iron Exhaust Manifolds
Bolt on instant performance by upgrading your restrictive factory manifold with this BladeRunner ported manifold. Designed to outflow the stock manifold by 12% for improved throttle response, this BladeRunner manifold has both the inlet and the outlet ports machined for a smooth transition and...
afepower.com
jeeeep
Hooked
I'm thinking of trying those, as much time and money as I've spent on all the other crap if these last a year it'll be worth it.Anybody have any experience with these?
BladeRunner Ported Ductile Iron Exhaust Manifolds
Bolt on instant performance by upgrading your restrictive factory manifold with this BladeRunner ported manifold. Designed to outflow the stock manifold by 12% for improved throttle response, this BladeRunner manifold has both the inlet and the outlet ports machined for a smooth transition and...
TeamFaust
Member
Has anyone actually tried these (afE Blade Runner exhaust manifolds) -- I am considering these as replacements to my cracked OEMs. I like the idea of staying with iron as too many comments floating around about others cracking or so hot the melt plug wire etc. Thoughts/experience?Anybody have any experience with these?
BladeRunner Ported Ductile Iron Exhaust Manifolds
Bolt on instant performance by upgrading your restrictive factory manifold with this BladeRunner ported manifold. Designed to outflow the stock manifold by 12% for improved throttle response, this BladeRunner manifold has both the inlet and the outlet ports machined for a smooth transition and...