2008 Cat C7: An Improvement Over Earlier Production?

[wrenchtech]

I am going to look at a bus that is for sale that has a 2008 C7. The C7 generally has reputation for being expensive to keep running an prone to having injector, oil pump, and turbo issues. I understand though, that by 2008 they had changed the injection system over to a common rail . And others have suggested that most of the problems that I described were more likely to be found in earlier versions from 2003, 2004, 2005 . That towards the end of the run, which I think concluded with the 2008 or 2009 model year, that Cat had worked some of the bugs out. Any constructive comments about this engine would be welcome.

[PNW_Steve]

When I wa looking at CAT i came across an aftermarket EGR cooler as well as an EGR delete.

Apparently they have trouble with the original getting plugged up.

[wrenchtech]

Originally Posted by PNW_Steve

When I wa looking at CAT i came across an aftermarket EGR cooler as well as an EGR delete.

Apparently they have trouble with the original getting plugged up.

I was hoping that there is a knowledge base of people hacking these engines for greater reliability and reduced costs.

Need to find out more about the differences in late and early versions.

[StatTarget]

https://www.youtube.com/channel/UCxz...85PAb0uXWTlWPw
Adept Ape has lots of good CAT info.

[wrenchtech]

Originally Posted by StatTarget

https://www.youtube.com/channel/UCxz...85PAb0uXWTlWPw
Adept Ape has lots of good CAT info.

I watched his video on bulletproofing your 3126/C7. Very interesting stuff. In that he focused on the high pressure oil system used to fire the injectors under the HUEI injection scheme, the failure of which would junk your engine, but he didn't address the 2007 - 2008 models and the changeover to common rail. And I don't remember if he addressed the clogging issues. Maybe that's in a video I didn't see yet.

[wrenchtech]

https://www.capitalremanexchange.com...ngine-history/

The original Caterpillar C7 would change configurations once again in 2007 to adjust to changing market demands. In 2007 diesel fuel itself changed to Ultra Low Sulfur Diesel or ULSD. The fuel change dictated that the fuel system of the CAT C7 ACERT needed to change to a common-rail injection system. The new common-rail injectors took injection pressures to 25,000-27,500 psi. The fuel transfer pump supplies the fuel to the fuel rail at 280 psi. Overall, the common rail system worked well but added another system or point of failure within the CAT C7 Engine.

Is this considered an improvement over the HUEI injection system?

If you read the article referenced by the link above, it seems like most of the problems were centered around the emissions reduction systems. There is a diesel particulate filter that clogs, as well as the EGR system and even the turbo(s) get clogged due to the emissions system. I would be interested to know if you can delete the troublesome components like folks are doing on every other diesel from BMW, to VW to Dodge and Ford pickups.

[cadillackid]

you can delete things if you have the computer software to disable the computer from expecting it to be there..

[wrenchtech]

Originally Posted by cadillackid

you can delete things if you have the computer software to disable the computer from expecting it to be there..

Yes, I was just talking about that with a friend. I dabble in Volkswagen TDI stuff. There are parties offering to make the ECU happy without a lot of the OEM systems for those engines. I suspect it's not as common with Cat.

[wrenchtech]

I misspelled the name (acronym) of the fuel injection system. It is HEUI, not HUEI, as I wrote. It stands for hydraulic electronic unit injector. This system is used on a number of Cat engines including the 3126 and the C7 as well as the Ford 7.3 and 6.0 powerstroke engines, and the International T444E.

Here's a good introduction to HEUI with images: How HEUI Injectors Work

[cadillackid]

the HEUI system was generally reliable as long as oil and fuel maintenance was good.. it proved problematic when people ran dirty oil and had bouts with bad fuel or crappy fuel filtration.. it simply became obsolete with newer emissions requirements and better fuel systems came available..



for international it had a long run as far as vehicle tech goes.. from 94 through 07..

[wrenchtech]

I was able to get maintenance records for the two buses that I’m looking at with the C7 engines. For all the tales of woe that I have heard about these engines, their record in these particular buses has been pretty uneventful. In 220,000 miles the only major repair required was the replacement of one failed injector, which cost the school district about $1000 to fix and which was not repairable by their local mechanic, but needed to be sent out to a distant cat dealer who had the special tools needed.

[EastCoastCB]

Originally Posted by wrenchtech

I was able to get maintenance records for the two buses that I’m looking at with the C7 engines. For all the tales of woe that I have heard about these engines, their record in these particular buses has been pretty uneventful. In 220,000 miles the only major repair required was the replacement of one failed injector, which cost the school district about $1000 to fix and which was not repairable by their local mechanic, but needed to be sent out to a distant cat dealer who had the special tools needed.

They're not the worst of the EPA engines.

I don't know that I'd own one but I'm super happy with my 3126 Cat so far.

[Ab01ns]

Originally Posted by EastCoastCB

They're not the worst of the EPA engines.



I don't know that I'd own one but I'm super happy with my 3126 Cat so far.

My 3126 just did 5000mi over 2 weeks with zero issues and 33psi oil pressure while running.

No complaints

[PNW_Steve]

You may find additional C7 info over on the School Bus Fleet forum:

https://www.schoolbusfleet.com/forum...TOPIC_ID=19600

[o1marc]

Originally Posted by Ab01ns

My 3126 just did 5000mi over 2 weeks with zero issues and 33psi oil pressure while running.

No complaints

It's not a C7 though.

This auction is strange. 2 hours left on the 1st on and 6 on the last one of 9 buses. All 05 C7's , FE's are at $1500 with no bids, the RE is at $2k with no bids. If the price stays where they are at I just may do something foolish. Why do they have to be so far away.

[o1marc]

Speaking of C7's and talking with the maintenance manager on a school flet of them, he says the biggest issue is cracking injector shells. Would you think a C7 that has already been repaired would be a problematic engine or one that's issues have already been addressed. The man said in his big fleet, he has only replaced a few injector shells over the years.

[EastCoastCB]

Originally Posted by o1marc

It's not a C7 though.

This auction is strange. 2 hours left on the 1st on and 6 on the last one of 9 buses. All 05 C7's , FE's are at $1500 with no bids, the RE is at $2k with no bids. If the price stays where they are at I just may do something foolish. Why do they have to be so far away.

I'm always finding amazing deals on cool vehicles... Out west in Cali, WA, and OR.
We should start paying PNW Steve to deliver unicorns to the Southeast.

[PNW_Steve]

Originally Posted by EastCoastCB

I'm always finding amazing deals on cool vehicles... Out west in Cali, WA, and OR.
We should start paying PNW Steve to deliver unicorns to the Southeast.

Sounds good to me

[o1marc]

This is wierd, seems all these buses have only one bidder besides me. I've let 3 go for $2k, got a couple more to go. The one I'm really interested in is the 06 RE going tomorrow.

[PNW_Steve]

Originally Posted by o1marc

This is wierd, seems all these buses have only one bidder besides me. I've let 3 go for $2k, got a couple more to go. The one I'm really interested in is the 06 RE going tomorrow.

Where are these buses listed?