NC11 - D3 200 - JamJar covers cracked

[bobmotor]

I bought a NC11 back in April and the engines have been giving me nothing but grief pretty much since then.

About three weeks ago, I realised that the bilge pumps had engaged and there was no alarm to indicate that they were running. As I was trying to figure out why they were running, I opened the engine compartment, I saw that the starboard jamjar cover was cracked and water was pouring into the engine bay. Bad luck I thought and got a new one and sorted it out.

Yesterday, the exact same thing happened but this time, on the port engine.

Once is unlucky, twice makes me wonder if there's something wrong.

Is anyone aware of any issues as to why these simple plastic covers would both fail within weeks of each other?

Also, from what I understand, the way the strainers work is that it's a negative pressure, i.e. it's sucking the water rather than positive pressure where the water is pushed through the strainer. If that is the case, anyone have any ideas as to why the cover and the strainer be blown clear of the jamjar?

The engines (D3 200s) have about 720 hours on them.

[Boatruptcy]

Sorry for delayed response.  Been a while since I have looked at the blog.  The cracked cover happened to me as well and it eventually blew off sending water everywhere.  I replaced and haven't had an in issue since.  One of two issues causes is, people steppling on this getting out of the engine compartment causing small cracks or over tightening them.  But, to futher answer your question, the raw water pump pushes water into strainger then then into engine, thus creating the pressure that causes the caps to fail if they are faulty.  Apparently, the newer Volvo D3's it is reversed, thus sucking water through strainer, which is a better design and makes easier winterization and engine flushing.