AMTK62
10-25-2008, 19:00
Hi,
My name is Michael. First, a little background on myself I think is in order. I am totally blind and I use screen-reading software for the computer. Put quite simply, any text on the screen is read aloud to me.
I have always, as long as I can remember, been interested in engine sounds.
Recently, I have been transported to and from school in a 2002 GMC/Thomas Minotour school bus with a 6.5l engine in it. I have a question about idle RPM for the 6.5.
I have heard (and ridden) other busses with 6.5's that idle higher than my current ride. Interestingly enough, on some older busses that are now retired, the 6.5's idle would very from bus to bus. Why is that?
On the newer busses with 6.5's (A few 2000's and our 2002), when put into park or nutral idles at the same rate it would if it were in drive. On some of the older busses (again, now retired), the idle would change depending upon what gear the tranny was in. When in park/nutral/what ever bus drivers put it in when they are not going anyware and picking up students, the RPM of the engine would increase. Back in drive, it would decrease.
So, my question is, why are there these differences? Some of our 2000's are now starting to idle higher; ours still holds the idle it came with when it was new.
Also, our bus was just discovered with a rusted-through tailpipe. The RPM the bus idles at results in vibrations throughout the bus body; if the RPM is increased, even just the slightest bit, no vibrations any more.
What would a rusted-through tailpipe require in terms of fixing? Would that require a total muffler replacement...and would that effect the sound or idle of the engine?
Thanks,
Michael
My name is Michael. First, a little background on myself I think is in order. I am totally blind and I use screen-reading software for the computer. Put quite simply, any text on the screen is read aloud to me.
I have always, as long as I can remember, been interested in engine sounds.
Recently, I have been transported to and from school in a 2002 GMC/Thomas Minotour school bus with a 6.5l engine in it. I have a question about idle RPM for the 6.5.
I have heard (and ridden) other busses with 6.5's that idle higher than my current ride. Interestingly enough, on some older busses that are now retired, the 6.5's idle would very from bus to bus. Why is that?
On the newer busses with 6.5's (A few 2000's and our 2002), when put into park or nutral idles at the same rate it would if it were in drive. On some of the older busses (again, now retired), the idle would change depending upon what gear the tranny was in. When in park/nutral/what ever bus drivers put it in when they are not going anyware and picking up students, the RPM of the engine would increase. Back in drive, it would decrease.
So, my question is, why are there these differences? Some of our 2000's are now starting to idle higher; ours still holds the idle it came with when it was new.
Also, our bus was just discovered with a rusted-through tailpipe. The RPM the bus idles at results in vibrations throughout the bus body; if the RPM is increased, even just the slightest bit, no vibrations any more.
What would a rusted-through tailpipe require in terms of fixing? Would that require a total muffler replacement...and would that effect the sound or idle of the engine?
Thanks,
Michael