Cummins ISB 5.9 L Diesel Engine Cavitation

[FCoover]

Hello All:

2000 Fleetwood Bounder 39Z

5.9 L - 275 HP Cummins Turbo Diesel
Allison 6 speed auto
Freightliner chassis.
85K miles

I took a 60 mile round trip run today. First 30 Miles - no problem.

I then stopped the MH for several hours - engine off while in a shop for State Safety Inspection.

4 hours later, the Mechanic started the engine- backed the MH out of the Service bay and turned the engine off.

The engine was off for 15-20 minutes. I Then started the engine and the yellow “Check Engine” light comes on immediately. It has never been on before.

I drive (limp) away from the shop with very little power.

The engine was running but did not seem to rev up or respond to the accelerator

I had barely enough power to get moving but not enough to go faster than 20 mph or climb an incline.

Then, about 3 miles down the road, the CE light goes out and the engine power surges back to normal

That cycle repeats maybe 3 times in about 5 miles then the CE light stays off and normal power resumes.

At that point I was afraid to stop and turn engine off so I pulled over and idled in Park for 20 mins- then headed for home. No CE light while idleing

On the way home, the CE light cycled on and off intermittently 5-6 times in 25 miles, each time with engine power loss and then normal power instantly when the light went off.

Each time the CE light lit, the engine would stay running, the engine would loose power to the point that the MH would barely move with the accelerator to the floor.

I barely made it up hills but got home.

2000 Fleetwood Bounder 39Z.

5.9 L - 275 HP Cummins Turbo Diesel. Allison 6 speed auto.
Freightliner Chassis 85K Mi.

Any thoughts on what’s causing the problem?

[Ljwt330]

My guess would be some issue with the turbo--either sensors, ecm, or even a loose hose. The loss of power as you describe is "classic" turbo symptom. Could even be caused by the inspection if hoses or electrical connections where loosened/checked but not correctly replaced.

Too late now, but it probably would have been wise to never leave the facility until the yellow light was accounted for. My suspicion is it will be something simple, but it's still a PITA that should not have happened.

[FCoover]

Thank you Larry!

[FCoover]

Hello All:

My mechanic advises that my loss of engine power is likely due to coolant cavitation causing perforations of the block. He wants to try block sealants- stuff put into the coolant to try to seal the perforations from the inside.

I’m not sure what to do.

I’m uncertain that the block is perforated.

If it is, I’m uncertain that sealants will work, last or be reliable.

I’m uncertain whether I should rebuild or replace the engine and if so where and what the cost will be.

I’m uncertain whether I should just junk the rig - sell it for parts and take a big loss.

Your thoughts and suggestions would really be appreciated.

Gloomy In Glenwood

[FCoover]

Hello All:

My engine has 85K miles and has been loosing power.

My mechanic advises that my loss of engine power is likely due to coolant cavitation causing perforations of the block. He wants to try block sealants- stuff put into the coolant to try to seal the perforations from the inside.

I’m not sure what to do.

I’m uncertain that the block is perforated.

If it is, I’m uncertain that sealants will work, last or be reliable.

I’m uncertain whether I should rebuild or replace the engine and if so where and what the cost will be.

I’m uncertain whether I should just junk the rig - sell it for parts and take a big loss.

Your thoughts and suggestions would really be appreciated.

Gloomy In Glenwood

[Mr_D]

ISB shouldn't get perforation from cavitation. There are no liners to be perforated by cavitation, it's a parent bore block just like most car engines. Cummins doesn't even recommend coolant with SCA's in it.

[BFlinn181]

A Cummins ISB 5.9 L engine is built with a solid cast iron block. Cavitation or erosion of the metal due to extreme shock waves in the coolant that can 'eat' the metal is NOT something that happens in a cast iron block. It can happen in engines with sleeved cylinders, not solid cast iron.

The coolant would leak into the oil, making it foam up and look like a mocha milkshake. Do you see evidence of this on the dipstick?

I'd seriously look for a second opinion by another shop.

[twinboat]

Run from that guy.

Besides not likely a cavitation issue, if it was, it would give you overheating or coolant loss issues, not low engine power.

[Mr_D]

Looks like my post got lost in the ether, but it was pretty much the same as bflinn.

[JNSNWT]

IMHO you need a new mechanic not a new engine.

[vsheetz]

Such diagnosis could be applicable to wet cylinder engines such as the ISC and ISL. The ISB is not a wet cylinder.

Definitly get another opinion.

Assuming the fuel filters have been changed? And changed again in case you got some bad fuel or the coach has been sitting an developed an algae problem.

[Webz]

From what I have read, 1st place to look when you have a power loss is the fuel system. Especially the filter and water separator. Also a dirty air filter will cause power loss. Good luck.
Be safe
John

[FCoover]

Originally Posted by BFlinn181

A Cummins ISB 5.9 L engine is built with a solid cast iron block. Cavitation or erosion of the metal due to extreme shock waves in the coolant that can 'eat' the metal is NOT something that happens in a cast iron block. It can happen in engines with sleeved cylinders, not solid cast iron.

The coolant would leak into the oil, making it foam up and look like a mocha milkshake. Do you see evidence of this on the dipstick?

I'd seriously look for a second opinion by another shop.

Wow! Im so glad that I posted. Thanks so much!

[johnhicks]

You can't get cavitation. You need to take that thing to a real Cummins shop.