YANMAR 3JH4E, 4JH4AE, oily? soot? in engine bay?

[dial_amonkey]

I've recently been looking to buy a Beneteau equiped with either a YANMAR 3JH4E or 4JH4AE engine - Oceanis 40 or 43.

I have noticed that a quite a few of the boats I've looked at have oily? black soot in the engine bay - Sometimes it's pretty obvious other times not at all but it seems to be in about half of the boats I have looked at - mostly very well maintained boats

I'm wondering if anyone can identify if it's a big problem the owner is trying to hide? or what it could be? where it's coming from? In the photos It's obvious on the back of the impeller case and on the orange tube.

Thanks for any input.

[noelex 77]

Welcome to the forum.

Your photos are not working, but it sounds like belt dust which is not a problem.

For the photos try these steps:
- Use 'Post reply' (just under the last post) rather than 'Quick reply'
- Scroll down and click on 'Manage attachments'
- Click on 'Choose File' and select your image
- Click on 'Upload' to the right of this
- When it has uploaded click on 'Close this window' at the top right, or at the very bottom of the page
- The image should now be attached at the bottom of your post (you can click on 'Preview Post' if you want to view it).

If you are still having problems attaching the photos send me a Private message and I will talk you through it.

[noelex 77]

I fixed one of the photos from the raw data in your post and yes that is just dust from the alternator belt.
Clean off the dust and check the belt tension. 10 min job. The worst it will mean is replacing the belt if its which is a standard service item anyway.

[DeepFrz]

It could also mean that the sheaves are out of alignment a tad.

[MARINE ENGINNER]

Originally Posted by dial_amonkey

I've recently been looking to buy a Beneteau equiped with either a YANMAR 3JH4E or 4JH4AE engine - Oceanis 40 or 43.

I have noticed that a quite a few of the boats I've looked at have oily? black soot in the engine bay - Sometimes it's pretty obvious other times not at all but it seems to be in about half of the boats I have looked at - mostly very well maintained boats

I'm wondering if anyone can identify if it's a big problem the owner is trying to hide? or what it could be? where it's coming from? In the photos It's obvious on the back of the impeller case and on the orange tube.

Thanks for any input.

hi dial_amonkey
can you tell me how old is the engine?
you possibly need to change the exhaust mixing elbow , i changed one in an oceanis 2008 that was corroded-leaking and the aft port fexible engine mount was rusted alot.the engine was a 4jh4AE yanmar

M.E

[dial_amonkey]

OK thanks all for all the input - great advice - when I'm back at the boat I'll check the the belt tension/wear/alignment and exhaust elbow.

The engine is 5 years old but and in excellent condition - no corrosion anywhere

(Will try now to add pics to the post)