C15 Myths?

What kind of mpg's are you getting so far? Not sure about what you've been told, it sounds suspect, but I'm no expert. Haney is only about 45 minutes to an hour south of Baltimore.

 

The rocker arm studs were upgraded when the "E" was about 6 months old from memory they did fail the new ones I do not remember any problems with them after that.
The Jake's, by the time the 2007's were out everything, rocker arms and cams had been upgraded. They can be used full pull.

 

Tuning by Mr Haney for sure. Just have your engine serial number and he will fill you in on your options.

 

You are in luck. Just south of Baltimore MD.,get in touch with Mr. Haney.

 

Here is the Stud Info for you.

 

With a 2007 you won't have any trouble with the rocker studs. Fuel temp wire won't hurt anything. Mr Haney seems to be the go to guy on here for ecm tuning. Bully Dog also has a downloader for a thousand dollars more. Not sure which one is better than the other. I always use the engine brake on high, never had any issues there.

 

The earlier 3406E and C-15/C-16 engines have a upgrade bolt for the jake brake housings and rocker arm shafts. The torque specs are dfferent when you upgrade the bolts also.

Far_Call has the studs listed for the upgrade on the VVA assemblies in the newer engines.

The earlier C15 Acerts would also need the rocker arm shaft bolts upgraded if they've never been done.

These engines would break these bolts resulting in serious damage that could even be bad enough that the cylinder head needs to be changed. Why one engine could go a million miles with the original bolts and another couldn't go 500,000 miles without breaking them is another mystery. I always felt it was a driver issue in how they used the Jake Brake constantly downshifting at high RPM to use the brake as much as possible and as many gears as possible while coming to a stop. Upshifting using the Jake Brake while float shifting.....it seemed that the same trucks with the same drivers would have problems, when other drivers/trucks never did.

With the upgraded bolts and studs the problems have been resolved for the most part. Make sure you've got the upgraded hardware in your engine and stop worrying about using it. Don't replace the hardware at every overhead service....replace with the upgraded hardware if you still have the original bolts and studs and forget about it.

As far as modifications for fuel mileage the biggest improvement in fuel mileage will come with a PDI Stage 1 tune. The other things you can do is replace the mufflers, raise the fuel pressure, make sure you have the updated primary fuel filter base and a recent overhead done.

I'll send you a PM. I am located roughly 1 hour from the Fort McHenry tunnel in Baltimore. I should have the capabilities to do the PDI tunes myself in a matter of a few weeks, instead of having to send the ECM to a PDI location for the tuning upgrade.

What is your engine serial number and Hp rating?