Carver 280 overheating

[Ricky mason]

Hi guys looking for some help and advice please , I have a carver 280 s , 7.3ltr v8 turbo diesel , I have recently got her back in the water / fresh water river in the uk , and I’ve had a few teething issues , she keeps over heating so I investigated and found that the impeller had ripped apart so I fished out the loose/ broken parts out of the pipe work , installed a new one , got it running to find it overheating again , so I re investigated and found that the new impeller had ripped apart again checked the hoses to find they was dry so it has ripped apart due to running dry and no water circulating the engine ! I have checked the inlet in bottem of boat where the water would be sucked up from and that’s clear with no blockage and the water filter was empty so although the inlets clear it isn’t sucking up water ?!! Help please TIA

[Ricky mason]

Pictures of my vessel

[Viper]

Welcome aboard Ricky.

I'm assuming the seacock is open and that the intake hoses are in good shape; not collapsed or kinked. Did you lubricate the impeller and housing before installing it into the pump? Are you sure you got ALL the broken impeller pieces out? The best way to tell is to try and fit the pieces together to see if you got them all. Sometimes they get stuck in the pump ports and can tear up a new impeller. You must also back flush the system as there are likely more pieces further down the circuit like an oil cooler or heat exchanger. It doesn't hurt to prime the hoses and pump with water first, and make sure all your hose clamps are tight so she doesn't suck air. Also, ensure that the replacement impeller is actually the correct one per engine serial number.

[Viper]

That looks like the old impeller. What did the new impeller look like after it failed?

[Ricky mason]

Qr Bbpost That looks like the old impeller. What did the new impeller look like after it failed?

That was the new one , it ran for 45 minutes then over heated and this is what I pulled out , the first time I changed it the impeller was in the same state as the second once taken out !thank you for the reply

[Viper]

Interesting. It looks to me like that one is old and brittle, and the core certaily looks like it's seen more than 45 minutes run time. Was this impeller siiting in the boat for years as a spare? If so, or on the shelf in a store/shop, they will get brittle after a while. UV does a number on them.

[Ricky mason]

Qr Bbpost Welcome aboard Ricky.

I'm assuming the seacock is open and that the intake hoses are in good shape; not collapsed or kinked. Did you lubricate the impeller and housing before installing it into the pump? Are you sure you got ALL the broken impeller pieces out? The best way to tell is to try and fit the pieces together to see if you got them all. Sometimes they get stuck in the pump ports and can tear up a new impeller. You must also back flush the system as there are likely more pieces further down the circuit like an oil cooler or heat exchanger. It doesn't hurt to prime the hoses and pump with water first, and make sure all your hose clamps are tight so she doesn't suck air. Also, ensure that the replacement impeller is actually the correct one per engine serial number.

Qr Bbpost Welcome aboard Ricky.

I'm assuming the seacock is open and that the intake hoses are in good shape; not collapsed or kinked. Did you lubricate the impeller and housing before installing it into the pump? Are you sure you got ALL the broken impeller pieces out? The best way to tell is to try and fit the pieces together to see if you got them all. Sometimes they get stuck in the pump ports and can tear up a new impeller. You must also back flush the system as there are likely more pieces further down the circuit like an oil cooler or heat exchanger. It doesn't hurt to prime the hoses and pump with water first, and make sure all your hose clamps are tight so she doesn't suck air. Also, ensure that the replacement impeller is actually the correct one per engine serial number.

Hello Thankyou for your response , yes the sea cock was open , I also removed the hose off of it while closed to check water was actually coming in and it gushed up so that was clear , the hoses all look in good shape and all clamps was tight , I am pretty sure it was all the pieces but due to not back flushing it I suppose I cannot be 100 percent sure ! Yes it was an identical replacement , perhaps I could have been more generous with lubricant too ! The second impeller was definitely more ruined than the first one I took out !

Qr Bbpost Interesting. It looks to me like that one is old and brittle, and the core certaily looks like it's seen more than 45 minutes run time. Was this impeller siiting in the boat for years as a spare? If so, or on the shelf in a store/shop, they will get brittle after a while. UV does a number on them.

. Yes this was a spare which had been on the boat atleast 3 years bud

Qr Bbpost Interesting. It looks to me like that one is old and brittle, and the core certaily looks like it's seen more than 45 minutes run time. Was this impeller siiting in the boat for years as a spare? If so, or on the shelf in a store/shop, they will get brittle after a while. UV does a number on them.

I’m very new to this boat as inherited from granddad so any advise is welcome ☺️

[Ricky mason]

Yes the replacement was sat on the boat for atleast 3 years so that sounds very likely , if that was the case would it just tare its self apart I assume ? Thankyou

[bud37]

Welcome to the forum and Carver.....dont know for sure but that maybe the first Bahamian flag I have noticed, .......anyhow you have got a lot of good advice there from Viper......get a new impeller,lots of lube ( dish soap and some water in this case), if there is a sea strainer between the pump and the thru hull, make sureties full and the top gasket is in place and sealed........after the engine starts, check for water flow at the exhaust if you can....if no flow shut down again....good luck man..

[Viper]

Ya the rubber isn't as pliable after several years but I would expect it to last longer than 45 minutes after only sitting for three years. It's probably older than that and if you didn't lubricate it when you installed it and it starved for water for a few seconds, that might have contributed to the failure. Always good to get impellers from a source that sells a lot of them or there's no telling how long they've been on their shelf. Between the retailer, distributor, and sitting in the boat for a few years, you can be installing an impeller that's over 5 years old.