broken exhaust manifold 04 8.9 cummins

[dick skeers]

today while at Redands truck and rv repair, I learned that my exhaust manifold was cracked. what have any of the rest of you paid for repair? can it be repaired (welded) or just relaced with a new manifold?
43,000 miles.

[Beagle RC Air]

You have a PM

Beagle

[Old Scout]

$800-$1000 is probably in the ball park but do your homework--there are a lot of dishonest folks out there--see this forum for reviews. Cracked manifolds are pretty common on our engine--again, see the forum for background. Cost of parts is pretty cheap here--mostly labor so wouldnt try welding the mainfold--not worth it.

[1peddler]

Get a quotation from Colton Truck.

Here is there web site :: COLTON TRUCK TERMINAL GARAGE ::

They are about 10 miles from Redlands Truck.

[Old Rv'er]

Previous posts have determined, proper cool down and warm up can prevent thses issues. Take care

[dick skeers]

thank you all for your responses and i will check with colton, having forgotten that i had satisfactory results with them a few yrs ago.

as to warm up and shut down, i believe that i am careful in that regard; however, if memory serves me there is a conflict between warm up instructions and reality. i believe that we're supposed to warm the engine to 140 degrees before driving. however, my engine won't warm up that high without the engine under some load. therefore, i let it idle a while and then drive slowly until it comes up to temp?? also, Old Scout, whom i respect says that once he starts his engine for the day, he never shusts it down, but rather lets it idle when stopped for fueling etc. how is this resolved with our engine manual which states that the super cooling capabilities will soot up your engine if you over idle??

also, does anyone know if the new replacement manifold has been improved to resolve this problem?

again, thanks to each of you for taking the trouble to respond, dick

[Old Scout]

Dick--I appreciate your vote of confidence--hope its not misplaced. Not sure what Cummins definition is for "over idling" but I wouldnt think 5-10 minutes at a truck stop for refueling or at a rest stop would qualify. The more likely definition is prolonged running/at idle overnight at a truck stop like some long-haul truckers do.

Length of engine cool down or warm up is probably debatable. In deference to my neighbors in the mornings, I move out of my parking spot as soon as the air bags are up and set in a common area or poke along an access road until temps are in the 150 range. Repeatedly starting and stopping the engine before it has reach a mid temp is probably not good either. As for cool down, unless you have just finished pulling a steep grade, a few minutes [2-3] of cool down is probably sufficient. Accordingly, several miles of driving thru city traffic before you shut down probably negates the need for a cool down period. Again, my thought on short idle periods vs shut downs [fueling/rest stops] is to reduce the number of warming/cooling cycles the manifold has to endure over its life-cycle. [Fewer cycles for you starter and reduces the amount of time the engine is cranking with little/no oil pressure.]

As for new manifold being better, the new manifold on my 03 looks pretty much like the old one--pretty flimsy when you consider that the turbo and the large intake and exhaust pipes hang off it as well. Seems like the newer engines [2005 and newer] do have slightly beefier manifolds but this may or may not be true.

[Old Rv'er]

Running a diesel engine at idle for excessive time causes the cylinders to load up with unburned fuel and that washes them down and it increases wear of those Cylinder walls. I believe proper warm up and cool down is more important than letting it idle for a long time. OTRT (over the road trucks) leave them running but companies are telling drivers to stop that because of the fuel waste and it tends to cause engine wear discussed above. If your MH is equipped with the feature you can get a fast idle by using the smart wheel on/off switch and the resume button which bumps up the idle to around 900-1100 which does not hurt the engine, and will warm it up to the 140 discussed here. If you have Aqua/Hydro hot with the engine preheat feature turning it on 3 hours in advance of your departure will also warm up the engine and your idle time will be less.