Low power on CAT C7 engine

[mlittle001]

I have a 2007 Winnebago Journey motorhome with a 350 hp cat c7 engine and Allison 6 speed transmission. The problem is low power when accelerating (has vibration throughout coach similar to driveshaft out-of-balance or that the engine is mis-firing). The transmission shifts too early and does not allow engine to come up to speed before shifting. Vehicle has been checked on computer - numerous communication errors detected between engine and transmission computers - BUT, no fault codes listed on engine or transmission. Problem is intermittent, but clears up temporarily if you stop and re-start vehicle. Also, fuel economy is down about 2 mpg. I have changed the fuel (both) filters and replaced the turbo boost actuator valve (low boost detected on turbo). Cannot figure out if problem is engine, transmission or chassis wiring harness problem. I am at wits end on who to contact for help.

[rver98]

I sent you a PM

[87_Fixr]

I hope I'm not duplicating what rver98 has said,but you may have an injector going bad and losing compression. A good Cat repair shop can take a compression test and quickly determine if the injectors and cylinders are ok or not.

[stuhly]

Go to your favorite Cat dealer. Most anyone else can't read Cat.

[MONGO MAN]

Quote:

Originally Posted by stuhly Go to your favorite Cat dealer. Most anyone else can't read Cat.

Try to find a CAT dealer Distributor with a on site dynometer -Ring Power in Centeral -N.E. Florida has them.But first call Cat Hotline 1-800-447-4986
"IF IT AINT A CAT IT's A DAWG"

[mlittle001]

Took it to CAT dealer, they were able to reproduce the problem (low power). The turbo has a crack in the housing and needs to be replaced. Should be ready later this week. The best part, it is covered under the 5 year engine warranty. Thank you for your assistance.