Yanmar heat exchanger inspection

[CharmCityBoater]

The rubber vanes on the raw water impeller should self correct themselves. I've never heard of this being an issue. Did you validate that this is really the cause?

I ask because I have had a diesel mechanic replace the raw water impeller before and he explicitly told me that the vanes would self-correct. Since he told me that I never worried about their orientation and have done it maybe 6 times with no ill effect.

Curious to hear from others on this...

[CrispyCringle]

Originally Posted by CharmCityBoater

The rubber vanes on the raw water impeller should self correct themselves. I've never heard of this being an issue. Did you validate that this is really the cause?

I ask because I have had a diesel mechanic replace the raw water impeller before and he explicitly told me that the vanes would self-correct. Since he told me that I never worried about their orientation and have done it maybe 6 times with no ill effect.

Curious to hear from others on this...

Interesting. I said they werent oriented correctly because when I took the cover off thats what it looked like- Half were splayed the wrong way. It does state in the maintenance manual to make sure they are oriented correctly. But it also seems like it would flip around on its own.

[CharmCityBoater]

Decided to read up on the vane direction issue and came across this article on marinehowto...

https://marinehowto.com/changing-a-r...pump-impeller/

Vane direction does not matter. That would not be the cause.

Thanks

[CharmCityBoater]

Originally Posted by CrispyCringle

Interesting. I said they werent oriented correctly because when I took the cover off thats what it looked like- Half were splayed the wrong way. It does state in the maintenance manual to make sure they are oriented correctly. But it also seems like it would flip around on its own.

According to the marinehowto article that is simply because as the motor stops the engine can momentarily spin in the opposite direction for a tiny amount of time causing this.

[CrispyCringle]

Pics from the OP....

Sea water pump cover. Too worn?



Heat exchanger pics

[ScottRhodes13]

If you don't want to wait for the raw water pump cover to arrive, just turn over the old one and reuse it.

[bil56]

you want a long life for your heat exchanger (and your engine)?
disassemble, clean, and change the seals every 2 years, and change the coolant

[Stu Jackson]

Originally Posted by CrispyCringle

Pics from the OP....

Sea water pump cover. Too worn?

Yes, definitely. 99% of rw pump issues: it's the faceplate.

[CrispyCringle]

Just to wrap this up, I ordered a new raw water pump cover plate. But as suggested, since there really is no difference by just flipping the cover over, I did that. I just saved the new cover for the next time.

I seem to be getting better flow with the new pump cover. Not a remarkable difference, but better. I may have just been a little worried over nothing. But better safe than sorry, and I know the engine a little better and have a good baseline on the raw water system condition.

[skipperpete]

Hmmm 99% of 4JH raw water pump problems RELATED to endplate issues are equally divided between the cover plate and the end plate at the inside end of the impeller housing, if one is worn, the other one must be in a similar condition.