Checking oil cooler for impeller bits

[bill209]

I just changed my impeller as it decided to teach me a lesson about not properly replacing impellers on a timely basis.

I assume the first place I should scrounge for impeller bits is the oil cooler.

I am not sure of the actual process, so I’m not sure if there is more I need to do than the following.

1. Turn off raw water sea cock.
2. Remove hoses from each end of the oil cooler.

At this point, I should be able to visually inspect and pull out bits of the impeller. I’ve also heard I can use a wet vac to push water back through the cooler as well as vacuum water out of the cooler.

I realize the hoses need to be inspected as well as the heat exchanger, so any information on inspecting the heat exchanger is also very welcome, but I can certainly open another thread for that specific question. Thanks everyone!

 

[Graeme Walker]

Engine?
Hours since last change?
Assuming you're talking water impeller, not oil pump?

 

[SeaDogAK]

Also check in the outflow fittings of the water pump itself.

 

[Mac2]

A common place missed is the hose from the strainer to the raw water pump. It is usually downhill from the raw water pump and impeller pieces will sink down to the strainer, and when you start the engine, they get sucked back up to the pump-restricing flow.

 

[Jeff F]

Agree with the above posts. Cleaning out the HX downstream of the pump should be easy, but I'd check the input side and pump before doing that.

Speaking from experience, with a Johnson pump it's hard to spot all leftover chunks when changing the impeller. Have a careful look in through the output side with the impeller out to make sure no remnants are hiding there.

I don't think you need to remove the cold side hose on the HX unless you want to do a complete inspection/cleaning. I'd take the two hoses connected to the water pump off, clean any debris out of the four connections and pump, and reassemble.

 

[nveater]

I changed impeller this summer and was lucky to find all nine vanes that had broken off the old impeller in the hose and opening of the oil cooler

 

[bill209]

Thanks so much guys for all the great advice!

 

[TF_BG]

Happened on my genset. I was able to attached a shop vac hose to the output hose of the water pump & suck the broken pieces back out.

 

[Bacchus]

I have used the wet/dry shop vac approach and it rather well. well.
I disconnected hose at discharge of the first HX and sucked at the pump with cover plate off. I next blew into the HX discharge hose w the shop vac. I alternated until I no longer got pieces out and was content that the volume of pieces were close to what was missing on the impeller.
I monitored appropriate temps after reassy & start-up.

 

[ramkay]

I just changed my impeller as it decided to teach me a lesson about not properly replacing impellers on a timely basis.

I assume the first place I should scrounge for impeller bits is the oil cooler.

I am not sure of the actual process, so I’m not sure if there is more I need to do than the following.

1. Turn off raw water sea cock.
2. Remove hoses from each end of the oil cooler.

At this point, I should be able to visually inspect and pull out bits of the impeller. I’ve also heard I can use a wet vac to push water back through the cooler as well as vacuum water out of the cooler.

I realize the hoses need to be inspected as well as the heat exchanger, so any information on inspecting the heat exchanger is also very welcome, but I can certainly open another thread for that specific question. Thanks everyone!

Bill, after you remove the hoses from each end, loosen up the bracket and remove the heat exchanger for a close up visual inspection, and pick up the pieces (see attached pic)

 

[rgano]

You did not state the engine, but it sounds that in your case the oil cooler is first in line. In my case the first thing in line is a return diesel fuel cooler followed by the intercooler tube bundle and then the oil cooler. Pretty unlikely any parts will get that far, not to mention the oil cooler and heat exchanger following the oil cooler.

 

[nveater]

Here was my find ! the oil cooler is first in line after the impellor on my Cummins

 

[grandbanksbayfield]

We have a Lehman 135 and on the first trip with it (bringing it back to Detroit from Western Lake Superior) we had some mild overheating. Pulled off the lake water pump to oil cooler hose and found a lot of old impeller fragments on the intake side of the cooler. Then we found a lot of white fragments on the intake side of the engine cooler which were from the zinc pencils that had dissolved sometime or another. The impeller seemed okay and it had been changed recently. We put about 100-110 hours on our engine per year. I change the impeller every year and keep the old one as a spare and check the zinc pencil. It is comforting.