Governor? 2000 Chevy 6.5 max 60mpg...

[abremer]

I have a 2000 Chevy 3500 6.5 Diesel short bus and it can only go 60mph and sometimes 'almost' 65mph. It will also begin to slow up as it goes up a grade. Motor runs great but it just seems to be governed or something. I've tried searching these forums but I guess I didn't do a good job because I couldn't find a specific answer.
Do most skoolies here keep their buses at these slow speeds or is it normal to change certain settings to get more speed?
I have a friend who used to work at the Thomas Bus factory in Tulsa, Oklahoma and he said he used to set the buses to only 55 or something like that. He said he'd put the bus on rollers at the factory and he could get them to 100mph and then he'd have to drop it down to 60 or so and then they'd set the max speed like that.
My bus is a Bluebird and not a Thomas.

[Danjo]

My 2007 6.6 liter does 85. I think it’ll go faster but I’m ascared!

The slowing down on the uphill says to me that you don’t have a governor.

Are you running at high RPM when you’re doing 60? Is it shifting OK?

Other thing I can think of is that you’re not getting enough fuel delivery.

[DAlgozine]

The older 6.5 GM diesels are not very powerful. Do a quick web search and you will find out the details. They can be worked over to perform and be reliable, but it will take some skills and knowledge.
The 6.6 Liter Duramax was a huge improvement both in performance and durability .

[PatrickBaptist]

Originally Posted by DAlgozine

The older 6.5 GM diesels are not very powerful. Do a quick web search and you will find out the details. They can be worked over to perform and be reliable, but it will take some skills and knowledge.
The 6.6 Liter Duramax was a huge improvement both in performance and durability .

6.5s are not really reliable, they get hot quick and are quicker than the 6.0 powerstroke at blowing head gaskets and cracking heads that was something you could rely on. The PMD in them were fickle, blame things would get to where they wouldn't restart once hot, mine left me stranded a few times that way. Only diesel I ever dealt with that didn't want to start once hot.

I wouldn't push it to run any harder than it's already set up for. I ruined one once that was in a prison van, made a good tool truck but when trying to use it to tow it was gutless pulling a 5500lb rover.
The 6.6 isn't an improvement, it's the difference between night and day comparing it to the 6.2/6.5s Chev had to do something drastic because the 6.5 wasn't even up for comparing to what dodge and ferd had in their platforms.

[zelseman]

Our 2000 3500 6.5 will do 100 if you force it to. Something is limiting your motor either a governor or fuel delivery.

[cadillackid]

Originally Posted by abremer

I have a 2000 Chevy 3500 6.5 Diesel short bus and it can only go 60mph and sometimes 'almost' 65mph. It will also begin to slow up as it goes up a grade. Motor runs great but it just seems to be governed or something. I've tried searching these forums but I guess I didn't do a good job because I couldn't find a specific answer.
Do most skoolies here keep their buses at these slow speeds or is it normal to change certain settings to get more speed?
I have a friend who used to work at the Thomas Bus factory in Tulsa, Oklahoma and he said he used to set the buses to only 55 or something like that. He said he'd put the bus on rollers at the factory and he could get them to 100mph and then he'd have to drop it down to 60 or so and then they'd set the max speed like that.
My bus is a Bluebird and not a Thomas.

if its really sluggish i would start by changing the fuel filters.. thats often the first sign is a little lack of power

[abremer]

Thank you for all the great information. The bus seems to have power and sounds good and gets up to speed fast but just seems to stop at 60mph or so. I've seen some videos where people are using the Tech 2 Scanner and turning off the speed limiter. I'll also change the fuel filter(s) just to be sure.

[Danjo]

Originally Posted by abremer

Thank you for all the great information. The bus seems to have power and sounds good and gets up to speed fast but just seems to stop at 60mph or so. I've seen some videos where people are using the Tech 2 Scanner and turning off the speed limiter. I'll also change the fuel filter(s) just to be sure.

It’s possible that you have more than one condition. You could have a governor and a dirty filter. Dogging on the uphills to me says fuel delivery or air delivery.

That’s a good find about the ECM programming. It would be worth $50 to rule that out.