Originally Posted by Retired JSO
That 6.0 International engine that Ford chose to up the horse power/torque every year to keep ahead of the Dodge/GM trucks was the real problem. I had 2 of them over the years. That same engine is still powering most international school buses in service without many headaches.
I havent read the whole thread, so maybe this has already been said.The 6.0 came about because the 7.3 could not be made "clean enough" to meet epa standards w/o limiting its power output to an unaceptable level.
The 6.0 is loaded with emision controls,the most problimatic being the undersized/poorly designed egr cooler.Another poor design choice was not useing enough cylinder head bolts,thus allowing the heads to lift. The variable ratio compressor wheel in the turbo was an attempt toclean up the turbo lag,and poor low speed boost performance of what was an undersized turbo in the first.The very small passages in the engine oil cooler are prone to clogging as well and needs to be flushed (on the coolant side)on a regular basis.
Lastly, you cannot directly compare the 6.0 that IH uses in its vehicles to the ford version due to the fact that the IH units are over 10k gross and are not all loaded up with emission controls.This was also true of the 2nd generation 7.3,however it did not have emission controls but was instead burdand withseveral design changes that Ford insisted on because of what they considered "driveability issues".In the case of the 7.3,all the issues can be tuned out,and the hp/torque brought up to specs that exceed the 6.0.Unfortuneatly when this is done, the 4r100 trans (which itself was never intended for diesel applications , being a 20 yr old design) becomes the weak link.This is easily fixed with a proper converter and "built" aftermarket trans.
So the bottom line here is that Ford was forced to build the 6.0,such as it is,by the EPA and the fact that the were cost issues as well.The transmission however, was a big improvement!