CUMMINS 5.9 ISB TURBO DIESEL

[dadd]

On the road currently travelling . coming into Colorado . 58,000 miles on 2004 Coachmen 35' motorhome with above engine and Allison tranny.Have noticed a seeming lack of power in mountains and the engine has acquired a "whistle" under load. Should it be brought to a service center ASAP or is there not any problem?? Never noticed the "whistle" until last month and hadn't tested it in mountains until now. IDEAS ??????

[dadd]

Result of Freightliner checkup ...... cracked exhaust manifold taking power from turbo.... on this Cummins the manifold is 2-piece .... running well now after $3800 repair WOW

[dadd]

wolfe10 wrote:
Do you have a boost gauge or something like a ScanGauge D or for more $$ Silverleaf so you KNOW what is happening?

If not, a very good idea.

Thanks for the links

[wolfe10]

Do you have a boost gauge or something like a ScanGauge D or for more $$ Silverleaf so you KNOW what is happening?

If not, a very good idea.

[dadd]

FOLLOWUP : Still on the road...replaced turbo air cleaner, checked for soot indications (only black residue on exhaust tip), still have the "whistle" .... hoping not to have difficulty crossing the high pass on the return east .... managed Monarch Pass coming west by using manual gear selection and keeping attention on RPM and temp ... hope to get into Cummins tech service when back home ... thanks for all the advice... what would we travelers do without our companion travelers ?????

[DSDP_Don]

"dadd".....Your coach engine would barely push along a station wagon without a turbo. The turbo is what makes these diesels go. The turbo pushes air through a CAC (charge air cooler) which is just a big aluminum radiator. It's typically similar in size to the engine radiator. The turbo is pushing air through that system at pressure. If it develops a leak, you will lose power.

If you're handy and physically capable, you need to look at your engine and follow all of the trbo connections and check for leaks. There is a very stout hose clamp with a large tension spring built in at every connection. You're looking for good/tight clamps. Typically, if they're leaking, they leak black soot and can be obvious. The last thing to check is the exhaust manifold, looking for cracks and black soot.

Hopefully you just have a loose or broken clamp.

[Dog_Trainer]

Mine did something similar when I broke a clamp on the turbo

[CVD]

Fiverwheel wrote:
On my 06 Cummins it was a broken exhaust manifold. Same symptoms as you are experiencing.

And that's an easy problem to identify, lift the bed (or however you get to the engine compartment) and take a look. If cracked, likely will be obvious.

[Fiverwheel]

On my 06 Cummins it was a broken exhaust manifold. Same symptoms as you are experiencing.

[ScottG]

Agree with others.
If the leak is bad enough, the EGT's wil sky rocket and you'll roast a piston.
Don't drive it any more than you have to and nothing strenuous.

[rhagfo]

Yep, sounds like a boost leak, will rob power.

[sch911]

Yes, I'd have it looked at. Could be one of the turbo intercooler hoses has a leak.