Exhaust Manifold...do they crack?

[steved]

Do the 3rd gen exhaust manifolds eventually crack like the 2nd gens?



I got a warble/whistle (a varying pitch, and not a steady whine like it should have) in the turbo that I just can't put my finger on... some times its there, sometimes its not, and its there more often when the truck is at operating temps.



I'm thinking I got a cracked something or other that's affected by heat.



Thoughts or suggestions on where to look?



It did it before the Smarty JR, and it will build boost to 42psi under loaded WOT... boost seems steady (as steady as a digital gauge off the MAP sensor can be.

 

[CDonaldson]

Pull your air intake tube and check the turbo for in/out play and side play . . your turbo may be getting ready to give up the ghost.





CD

 

[Shadrach]

The 3rd gens didn't crack like the earlier ones did but they still can if overheated. Shadrach

 

[steved]

Turbo looked fine, first thing I checked. Been doing this for 30k... I'll check the turbo again.

 

[JRutledge]

Mine didn't crack, but after 125k miles towing in Alaska summer and winter the manifold pushed the #6 gasket out the rear. It really whistled when I put the jake on. what a pain. The manifold was so distorted that you couldn't hope to reuse it. I started taking the bolts out from the ends to the center as I had read about this problem and after the first three bolts were out the front hole was completely obscured. I installed an ATS two piece and have been happy with it so far. It's got about 6000 miles on it with no real towing yet. I also installed an Edge Juice with Attitude module at the same time. That way I can monitor my EGT and it has the shut off timer built in so when my crew drives it they cant forget to let the turbo cool down.

View attachment 75277

 

[jelag]

I've got 3 trucks that have the same problem as JRutledge, and when we pulled the manifold we were at least able to remove the broken studs with no problems... I like the design of the ATS, that what we used... .

 

[SSovaiko]

My 06 had the exh crack, replaced under warranty but they buggered up the rear coolant tube and bracket - will likely crack the tube if I try to bend it back in place.

 

[steved]

I'll need to investigate this further... makes me wonder, with over 200k, what mine might look like. I got to run new lines for my bypass this weekend, so I'll check it out then.

 

[steved]

Hmmm, how much is too much???

I've got no end-to-end play, but I can feel a little movement up/down in the shaft... some play has to be normal??



If it is the turbo, what should I do?? Buy a reman'd unit from Cummins or go aftermarket?? What would be the best replacement for almost no power mods (40hp sticks and a SmartyJr) and staying single?

 

[rscurtis]

I but a BD Super B on my '03 along with their manifold, and you will not be disappointed. Lower boost pressure, slightly higher EGT (after turbo), no loss of throttle response, no smoke, and I believe there is a slight MPG improvement, I'm not through quantifying that yet. This dual volute turbo, with a waste gate for each section is what should have been put on the truck at the factory. The only downside is that you'll have to shorten the engine pipe about 1-1/2 inches. If you were thinking about a new exhaust system, now is the time. This truck has stock fueling also.

 

[steved]

Stupid question, but would a leak at the air intake horn cause a whistle? This started right after I had the injectors replaced the last time, and I believe that means removing the air intake horn and grid heaters... if those gaskets are compromised???

 

[JKreiss]

I've gotten whistles from the inter-cooler boots, as well as the manifold to turbo gasket. The intercooler boot would only whistle under hard acceleration . The turbo to manifold gasket barely whistled but when i'd hit the exhaust brake it would scream. Probably not your source but just a couple other things to check fwiw.

 

[steved]

I was thinking of things that would have been apart to replace the injectors... but anything is possible... got to start taking things apart, just to inspect it if nothing else.

 

[Walker1]

Ya, the grid heater and horn both come off for a injector change.