2006 Cummings 6.7 benefits/negatives

[t-chuck]

One bus I have found is "2006 Thomas 30Ft bus, 32 Passenger, 6.7 Cummins Diesel, 3000 series Allison trans. 130,000 miles."
I am curious about the real-world benefits/negatives of the early emissions on this engine.
Overall forums say they are less reliable due to the complexity of the computer and emissions. Is this an on going problem or is it something that can be mitigated with really good maintenance or or cured with a $5000 dollar systems rebuild?
Also, aside from being cleaner, do these systems have any notable benefits like more power or better fuel economy?

[BamaBus]

What emission controls does this have? If it is the bus I think it is, then it has an egr but unsure of the rest. Also confirm the actual mileage. Ceiling height may not be the high version.

IMO you will have better emissions on this vs older engines and without dpf, less to repair. The egr system will need repair at some point.

I’m not sure what maintenance can be done on a computer other than repairing it when it or the peripherals become defective. At some point it will need repair. Maintaining the fuel, oil and cooling systems is important to help prevent any problems.

I don’t think emissions by themselves help power but maybe fuel economy. When you have a better transmission then you can get an engine with higher torque and horse power.

[PorchDog]

Should not have DEF. Just EGR possibly.

If I was going to have to buy an "Emissions" engine-- the 6.7 Cummins would be my choice. I don't know how much carryover there is from the Dodge pickup truck side of things-- but tons of aftermarket support exists for the Dodge's.

[t-chuck]

Since your in AL it is probably the bus you are thinking of with the wheel chair lift. Do you know if the seller has a good reputation?
How to you confirm the miles on the bus? or engine?

[BamaBus]

Originally Posted by t-chuck

Since your in AL it is probably the bus you are thinking of with the wheel chair lift. Do you know if the seller has a good reputation?
How to you confirm the miles on the bus? or engine?

I don't know the seller. Could not find an AL dealers license for the name in the FB ad. A phone number listed in the ad is the same as a party bus company in that area. The listing of the bus where they purchased it from says "Odometer may have been changed. Check engine light is on, low coolant light came on and appears to overheat." To get a more accurate mileage someone would need to access the ecm. All of the issues this bus has may have been addressed by the seller and should have some documentation of repairs.

See pm.

[1dmpo]

Don't know why no one else has brought this up, but the 6.7 Cummins didn't come out until late 2007 and most school buses that got it are going to be 2008 or later. If it actually is a 2006 and a Cummins it should be 5.9 which will not have any of the emissions stuff on it, the 6.7 was got the increased displacement to compensate for all the added emissions stuff.

[DeMac]

Originally Posted by 1dmpo

Don't know why no one else has brought this up, but the 6.7 Cummins didn't come out until late 2007 and most school buses that got it are going to be 2008 or later. If it actually is a 2006 and a Cummins it should be 5.9 which will not have any of the emissions stuff on it, the 6.7 was got the increased displacement to compensate for all the added emissions stuff.

This article by Mike McGlothlin supports 1dmpo. No 6.7L was offered before 2007.5

www.drivingline.com/cummins-history-lesson
..."the big news on the 6.7L was that it was the first Cummins saddled with exhaust gas recirculation and a diesel particulate filter"...


The Canadian Public Transport Database supports the same, regarding 2007 Thomas buses, being the first year to offer a 6.7l option.

cptdb.ca/wiki/index/Thomas_Built_Buses_Saf-T-Liner_HDX

Can we find a souce which supports a 6.7l Cummins (ISB) being offered by Thomas, w/o the aforementioned emissions equiptment and/or sold by Thomas in 2006?

Note: in addition to the egr & dpf, the '07 6.7L also has Bosch common-rail injection & variable geometry turbo.

[fo4imtippin]

I have never seen a common rail 5.9 in a bus either. They jumped from vp44 24v 5.9 stopping in 2003 to isb 6.7 in 2008. They did have the ISC going in-between though. For Bluebird, Cat c7 or Cummins isc filled the Gap and frightliner and Thomas seemed to use Cat c7 and Mercedes I6.

[t-chuck]

I was curious about that engine in that date bus as well. Here is a picture of the engine if that helps.

[DeMac]

ISL or ISL G (natural gas)

Verification: Seventh digit in the vin# will be an 'E' or 'F'

Multiple threads this weekend asking about 2006 Thomas buses with 2008 Cummins engines. Not always correct, particularly the sellers.

Skoolie shoppers might consider learning Cheese_Wagon's the-ten-skoolie-commandments before purchacing.

[t-chuck]

Thanks DeMac, looks like the last person that was selling this bus gave me the wrong engine information and I assumed the others in the lot were the same. The VIN does indeed have E for the 7th which according to cptdb.ca wiki page (I can't post links yet as a newbie) is an 8.9? ISL engine. They have the natural gas version as F. The VIN just has D for ISB engines. I don't know what size though.

[musigenesis]

Originally Posted by DeMac

Skoolie shoppers might consider learning Cheese_Wagon's the-ten-skoolie-commandments before purchacing.

I love reading this and reminding myself that I broke nine of these.

[BamaBus]

Originally Posted by t-chuck

Thanks DeMac, looks like the last person that was selling this bus gave me the wrong engine information and I assumed the others in the lot were the same. The VIN does indeed have E for the 7th which according to cptdb.ca wiki page (I can't post links yet as a newbie) is an 8.9? ISL engine. They have the natural gas version as F. The VIN just has D for ISB engines. I don't know what size though.

Using the info posted in this thread https://www.skoolie.net/forums/f10/u...ion-37958.html These buses have the 215hp Cummins ISB. Being that the engines were manufactured in 2005 makes me believe it is the 5.9, not 6.7 the FB reseller is stating for his previous purchases from GDeals.

[DixonM]

It is more than likely a 5.9 with common rail injection with an EGR system on it. Not a bad motor but look for blowby as they have had some issues with breaking rings. Not all of them have the issue with the rings but mine did.