Impeller / Cummins enging

[sparky]

Hello and a question to all of you who have changed your impeller already!

We have the Cummins 130 hp engine with the sherwood 10516 impeller. We pulled the cover off yesterday (<100 hours, long story) to check the impeller and the photo below is what we saw.

Questions: 1. Has anyone had the vanes of the impeller turning in different directions like this?
2. Do you have a "keyway" in the slot on the impeller hub? I am wondering if there is a keyway but it is short and I won't be able to see it until I pull the impeller off.
3. How do I extricate the impeller anyway?



Thanks!
Sparky

 

[sparky]

Sherwood 10615K impeller that is. 😳

 

[bbrh842]

Regarding the vane pointing the wrong way. This is not abnormal. When the engine is stopped, it may back up slightly due the piston that is on the compression stroke. Notice the vane that is backing up onto the flat side of the housing is the only one that has been redirected into the wrong direction. Soon as engine is started, it will turn back in the correct direction.

 

[captd]

Don't look like that one needs pulling, but if you do a couple needle nose pliers opposite each other will normally get them out. Don't take it out for practice. You could break a fin pulling it out. Like I said it looks good to me. As mentioned in the above post " that is normal " Don't hurt to have a spare tho. 😉
captd

 

[C Suite]

I have the 150 hp cummins and mine has the key way. I lost the impeller at about 120 hours. I happened to be 50 miles from help. It was an expensive tow. Make sure you carry a spare.

 

[sparky]

Don't look like that one needs pulling,

According to Randy at Cummins NW, it does need pulling. Upon closer view, one of the vanes shows some damage (cavitation), and there is separation on the right side - see just to the right of the part # on the hub - that gap should not be there. We have less than 100 hours.

I carry 2 spare impellers for the engine, one spare impeller for the generator, 2 spare oil filters, 2 spare Racor filters, numerous zincs, thruster fuses, etc. And one huge tool box.

Sparky

 

[sparky]

I have the 150 hp cummins and mine has the key way. I lost the impeller at about 120 hours. I happened to be 50 miles from help. It was an expensive tow. Make sure you carry a spare.

May I ask how you know you lost the impeller? I likes to be educated! :?

I always have a Boat US/Vessel Assist/SeaTow membership at all times. Been towed twice with our old boat and 10 years of membership fees paid for themselves 😳

Sparky

 

[rt11002003]

If you lose the impeller, engine temp will rise. If it comes up enough you'll get the alarm.

Gene

 

[sparky]

Gene

That is what we thought, but we have a 155IMT High alarm on our SmartCraft which is an overheat alarm, but we can not find the cause. Even with the boat turned off for a week, when you turn the key to open the SmartCraft screen (not even starting the engine), the alarm pops up showing a temp of 203 degrees. That is why Cummins NW suggested we open the impeller. As that is not the problem the next action is waiting forever for Cummins folks to get to our boat (in Virginia) to check for a faulty sensor....

Thanks!
Sparky

 

[captd]

Don't look like that one needs pulling,

According to Randy at Cummins NW, it does need pulling. Upon closer view, one of the vanes shows some damage (cavitation), and there is separation on the right side - see just to the right of the part # on the hub - that gap should not be there. We have less than 100 hours.

I carry 2 spare impellers for the engine, one spare impeller for the generator, 2 spare oil filters, 2 spare Racor filters, numerous zincs, thruster fuses, etc. And one huge tool box.

Sparky

Picture is not all that clear. Looks in the picture don't count. You bet it should be changed based on what you said. It probably still pumped enough water to cool the engine. I would keep it for a spare. Course I am a cheap guy. 😉 Must be other problems. :cry:

captd

 

[captd]

Don't look like that one needs pulling,

According to Randy at Cummins NW, it does need pulling. Upon closer view, one of the vanes shows some damage (cavitation), and there is separation on the right side - see just to the right of the part # on the hub - that gap should not be there. We have less than 100 hours.

I carry 2 spare impellers for the engine, one spare impeller for the generator, 2 spare oil filters, 2 spare Racor filters, numerous zincs, thruster fuses, etc. And one huge tool box.

Sparky

Picture is not all that clear. Looks in the picture don't count. You bet it should be changed based on what you said. It probably still pumped enough water to cool the engine. I would keep it for a spare. Course I am a cheap guy. 😉 Must be other problems. :cry:

captd

Addendum: After blowing up the picture I still don't see a problem. Must be a small flaw.

 

[bbrh842]

I just fugured out YOU CAN BLOW UP A PICTURE !!!! There is clearly a gap between the rubber part of the impeller and the metal hub. I would be willing to bet the metal hub is turning but the rubber part is just sitting there. That would certainly cause an overheating problem in just a couple of minutes. I never heard of an impeller failing in this manner. Typically they just wear out, maybe a few chunks of rubber break off the tips of some of the vanes. Over a period of time you might notice the engine is starting to run a little bit warmer than you are used to seeing. Especially at high throttle settings. There is usually plenty of warning to give you time to deal with the issue before it becomes a crisis. If you hold your mouth right, an impeller should not have to be changed, except every 1000 hours, as part of routine maintenance. In my last boat, which I drove relentlessly for 10 years, I NEVER changed the impeller. Maybe I was just lucky? Maybe Yanmar just puts better stuff in there?

 

[Doug in Williamsburg]

3. How do I extricate the impeller anyway?

Sparky,

To extricate the impeller, an impeller removal tool is highly recommended. Mine are made by Jabsco. They come in sizes to fit the diameter of the impeller.

--Doug in Williamsburg

 

[captd]

Ok, I see what your pointing out. I was looking for broken fins. Never seen one separate like that before. It is actually spinning on the hub, Huh?
No good for a spare. :roll:
captd

 

[rt11002003]

Sparky,

I'm not familar with your instrumentation. However, it is typical for engine panels (instruments) to be set up so that when the key is turned to "on" all the alarms engage "go off", that's to tell one they're working, noise and lights. When the starter engages the alarms go off shortly thereafter, unless there is a real issue.

With that said, I recently purchased oil pressure and coolant temp gages to install in my R-21 EC. The temp gage reads 170+ degrees without being hooked up. I don't remember if that is normal, so a phone call to the supplier is needed.

I'm a believer in the benefits of electronics, but sometimes I think we go overboard in their use.

I'd suggest changing that impeller. Go to Radio Shack, or some other supplier, and buy yourself an IR heat detector. When you have alarms and instruments that you suspect are wacky (highly technical term 😉 ), point the detector at the engine's thermostat housing and read the temp. If it's within limits you're OK, unless the alarm/instrument is measuring temp for a special purpose in a special place. Wouldn't surprise me, some folks feel if one can do something with electronics, then it should be done. Even if there isn't a need.

Enough of my ranting. 😀

Gene

 

[sparky]

Thanks to everyone!

The impeller extraction tool purchased at West Marine works like magic. Sort of like opening a bottle of wine.....

I also learned a great tip from my Cummins Tech. He curves the impeller blades (like you see in the pic) and secures them with a tie-wrap to compress the impeller so you can actually insert it into the housing. Once almost inserted, cut the tie wrap and remove it. Worked like a charm and I was wondering how to get that impeller into a housing that appears smaller than the new impeller!

Also learned that the cover plate that you remove (4 screws) to access the impeller needs to be replaced periodically. Ours was showing some signs of wear already. If it wears too much it will create an air pocket and adversely affect the function of the impeller. The real question is why has this happened with well under 100 hours of use? Maybe something having to do with that gap in the old impeller pointed out by tugnut "bbrh842"? I will be sending the pics to Cummins NW and see what they have to suggest. Maybe I just have a bad impeller unit....

I would caution other TugNuts not to take their impeller for granted. Opening the housing (after closing the Seacock!!) is easy, so you can view the impeller and check the cover plate.

The OTHER PROBLEM was indeed a faulty SENSOR that had to be replaced. A $121 part that took over an hour to replace due to its location under the alternator and basically working blind in a spot on the engine right under the threshold for the door to the boat. A Cummins mechanic took care of this, there was no way this was a do-it-yourself project. The alarm is finally silent and my SmartCraft no longer thinks the air intake temp is 203 degrees. I am only glad it was under warranty!!!

Sparky

 

[bbrh842]

Gene,

I agree an infrared heat detector is a good thing to have around a boat. I looked EVERYWHERE for one. Radio Shack had no clue what I was talking about. Finally found one at Sears Hardware.

 

[rt11002003]

bbrh842,

Thanks for the Sears tip. I left my last one on a boat I sold, stupid me. 🙁 I would have sworn I bought it at Radio Shack.

Gene