Hey guys,
I was checkin the oil in my truck today and I noticed that the side of my rocker cover had some soot on it. Upon closer inspection I noticed that my exhaust manifold has a crack in it. It's in the center rear tube where it bolts to the turbo. Now here's my question should I just weld it or should I buy a new after market High performance manifold? What are the benefits of the after market ones?
Thanks,
Topper

 

Topper
I'd say a new manifold. You might be able to get away with welding but not the best thing to do. The after market manifolds say they prevent this very thing. They aslo say it will give you better spoolup. jmho.

 

we all know how fun it is to weld cast.... but hey for the price its worth a shot, at least when it cracks again you will already know where all the bolts are.... heat 'er up and put one of those nice red nickle rods on and give it a go.

 

Thanks guys,
I may just buy a new one. So whos should I buy???
Topper

 

If you're going to buy a new one, do it right and get an ATS or an HTT manifold and you won't have to worry about it again.
mishkaya

 

Cracking isn't the only problem with the stock manifold. They also shrink, and can bend the mounting bolts. In extreme cases, on 12v's, the mounting boss on the head can be cracked from the shrinkage.

 

I went with an ATS manifold, everything went smooth except that the turbo mountin studs didn't go in as deep as they did in the stock manifold. But a set of washers cured that. I didn't really notice any difference in spool up, but I was just happy I didn't have to worry about splitting my manifold on the 2 hour trip home.

 

BD has a manifold now too. I don't know if there is any difrance from the ones already mentioned. I remember some saying cummins makes a two piece manifold for the 5.9 but it may not work in our trucks.

 

I put on the ATS after my OEM cracked pretty badly; The only thing to worry about is making sure that you re-tighten the mounting bolts a few times, they appear to have a stretch / relax problem even with the low torque they're under - probably due to the temp extremes they see.

 

I just added an HTT manifold....more long term planning for twins than having any real problems.

I was VERY impressed with the quality, easy fit, and performance!

The pre tapped pyro hole is 1/8"...so if you have ISSPRO gauges, there is still some work to do!

I noticed faster spoolup and better cooldown.....but this may not be just the manifold. I found one stock manifold bolt (#3 bottom) finger loose...but not much leakage. Also found some leakage around the turbo to manifold gasket. How much these two problems affected performance .... I don't know...but the leaks were minor . I sure love the noticable difference in performance level after installing the HTT manifold!

RJ

 

BTW, ways the torque spec on the exhaust manifold bolts. ?

 

02 Service Manual calls for 32 ft-lbs. Standard procedure....Start with #3 top and work outward...clockwise...#3,#4,#2,#5...etc.

RJ