The compression ratio is 16.5:1 or so. I suspect you are looking for
cylinder pressure, which should be well beyond testing with any reliability
by common compression checking equipment....... over 2000PSI. Most diesels
are measured in "bars", and need rather complex and expensive equipment to
measure cylinder pressure.
If that doesn't answer your question, post more details.

Signature
Max
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
> The compression ratio is 16.5:1 or so. I suspect you are looking for
> cylinder pressure, which should be well beyond testing with any reliability
[quoted text clipped - 3 lines]
>
> If that doesn't answer your question, post more details.
I was looking at a 2500 for sale and I don't know the quality of the
maintenance history. I was thinking about a compression test. Sounds
like this would be a tough test to do tho.
How would you go about testing the quality of a hi-mileage 5.9 Cummins?
Max Dodge - 28 Jan 2006 15:35 GMT
Wha kind of mileage does it have? Anything less than 250k and the truck
should be ok as far as mileage is concerned. Its rather difficult to
evaluate a Cummins without taking an oil sample for analysis, but look at
the oil after having driven it for a bit. Any irregularities should be
noted, such as metallic oil, or a brown color. Listen to idle quality, as
that will tell you if a cylinder is not firing quite right. A diesel should
be very even in its firing after warmed up. If you have access to one, take
a scanner and pull codes from the truck, if there are any. Take the VIN and
run it both with Dodge and the Carfax service.

Signature
Max
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
>> The compression ratio is 16.5:1 or so. I suspect you are looking for
>> cylinder pressure, which should be well beyond testing with any
[quoted text clipped - 12 lines]
>
> How would you go about testing the quality of a hi-mileage 5.9 Cummins?
Max Dodge - 28 Jan 2006 15:35 GMT
Wha kind of mileage does it have? Anything less than 250k and the truck
should be ok as far as mileage is concerned. Its rather difficult to
evaluate a Cummins without taking an oil sample for analysis, but look at
the oil after having driven it for a bit. Any irregularities should be
noted, such as metallic oil, or a brown color. Listen to idle quality, as
that will tell you if a cylinder is not firing quite right. A diesel should
be very even in its firing after warmed up. If you have access to one, take
a scanner and pull codes from the truck, if there are any. Take the VIN and
run it both with Dodge and the Carfax service.

Signature
Max
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
>> The compression ratio is 16.5:1 or so. I suspect you are looking for
>> cylinder pressure, which should be well beyond testing with any
[quoted text clipped - 12 lines]
>
> How would you go about testing the quality of a hi-mileage 5.9 Cummins?