2008 VP cooling problem-help please.

[solar]

Two weeks ago returned to my marina from a few hours of sailing - all nice & well.

TODAY,started engine to go out again and NO water was coming out at 1000 RPM?
Turned engine off after 25-30 sec.

VP D1-30B engine with VP saildrive,330 hours,new impelor,saildrive was cleaned in April 2010 when A/F boat, NEVER had any problems with cooling system ever.

Sea cock is open and feels normal.
Opened raw water filter - clean but empty of water.
Opened impelor house - all new and well.

Put some water into filter house,started engine = the water came out O.K

Flushed with a water hose from the water filter down to the sea cock/saildrive to open any blockings and started engine after that SOME water came out but only at 2000 and up RPM.
This went on for about 10 Min.
Very little water if any came out at 1000-1400RPM so I kept the high rev during this try.

At second try after 15 Min... again NO water came out at ANY rev.

Cooling hoses/system looks clean and unblocked.

The marina water are too mudy to see anything by diving to look at the saildrive from below.

Before calling the $$$ VP expert...what am I missing here?

Many thanks.

 

[VicS]

I think I'd start by taking a very critical look at all the suction hoses and very especially at the strainer and its lid and seal , looking for places air could be sucked in.

It seemed that it was Ok when you filled the strainer with water but that it lost its prime very quickly once stopped.

I'd take another critical look at the pump too. Even replace the impeller despite it looking OK

Possibly a hose collapsing internally but you expect it to be Ok at low speed and troublesome at higher speeds.

Air getting in to the strainer I bet!

 

[solar]

Thanks a lot VicS!

Yes. strainer ,seal and lid can be the answer.There is a rubber sealing ring there that I may misplaced (was cleaning the strainer filter BEFORE the above cooling problem started...hummmm) ? or lid not closed strong enough?

I'll also look again at all hoses/clamps to avoid air sucking in.

Will be back at the boat soon (NOT soon enough,can't wait now ) and will report results.

ANY other ideas guys?

This forum is a life saver! love it!

 

[vyv_cox]

I have experienced some priming problems due to wear of the pump faceplate. Even with a new impeller there can be a gap at its end that will prevent correct operation. The symptoms were not quite what you describe but could be worth looking at. I occasionally find that after sailing in rough conditions the suction hose will empty and the pump will not draw. I keep a bottle of water in the bilge to refill the strainer when this happens, which always fixes it.

Try leaving the strainer open, assuming it to be above the water line, and filling it with a hosepipe as the engine runs. If all is then well it tells you that there is a problem upstream of the pump, or the pump itself.

 

[VicS]

or lid not closed strong enough?

I don't know if it applies to your strainer or not but I believe over tightening some can cause distortion and leaks

 

[rogerstown]

Hello Solar

About once every season at low revs my, VP with saildrive, pumps out very little water and it is hot with some steam. I have found that taking off the intake and blowing through fixes the problem. Maybe worth a try.