Water pulling from water pump to exhaust

[southcoasting]

Newbie question

How long does it take for the A4 to start pulling water in and out through the exhaust?

Reason I ask is because I turned on my engine today for about 1 minute and noticed no water coming out. I checked the tail end of my water pipe that I had put into a 5 gallong bucket of water and noticed it was not pulling anything...

Does it take a while for the system to cycle through or something? Or maybe I have something else going on?

[Mo]

Water should be coming out in 30 seconds or so.
It does not pull water in through the exhaust. The small hose coming from the thru-hull to the pump is your intake. So water comes in to the raw water pump and is pumped through the engine and is expelled through the transom outlet (exhaust).

-You need to look for the raw water pump on the Left rear of engine (flywheel facing you) and will see the pump.
-water bucket should be placed close to hose (you are looking for a hose that comes in through a thru-hull and goes directly to the pump...there may or may not be a T in that line with another valve on it)....
-the thru hull needs to be turned shut; the T opened up and draw from your bucket with that line. The pump should just draw the water.
- You may need to prime your pump as I've heard of people needing to do that....never had the problem myself or on anything I worked on.

Is this your first year with the boat and was anyone working on it. If so, although a stretch, ensure you have a working impeller. If the engine is run for prolonged periods without water the impeller gets damaged and goes to pieces.

If that is the case you will need to check the elbows just above the pump to ensure there is no blockage there as well (If the impeller is damaged). Damaged impeller with pieces missing means you look at the elbows to find the missing piece as they usually jam there and block everything off.

If I have misunderstood your post my apologies...but hope this helps you out.

[ndutton]

We also need to know what type of cooling system you have, early model Dole or late model Holley, raw water or fresh water cooling. They behave differently when cold.

Give us lots of pictures, they really help. Pics of the engine showing the thermostat housing would be nice. If running out of the water, get a pic of your temporary water attachment too.

[southcoasting]

Thanks Guys,
I did indeed put the hose to the intake...Sorry for the confusing explanation...I just did not notice any water coming out of exhaust so got nervous...I then checked the intake hose inside the bucket and it was not pulling anything...but like I said, I did not let the engine run long as I immediately shut it off when I checked the suction of the hose and and I felt nothing being pulled...It is a pretty long hose though and it could be that I did not let the system prime itself...

It's a fresh water system and I had the bucket of water on the ground instead of on the boat as I feared flooding the engine...

The boat is on the hard and the water pump is a Jabsco with a brand new impeller I just installed today...

Not sure about the type of cooling system but here are some pics:

[ndutton]

OK, looks like a late model FWC to me. I suspect you're asking too much of the raw water pump to draw up 5 or more feet. I suggest putting the bucket on the cabin sole and drawing from there.

I'd replace the impeller on principle too. It's been run dry long enough for damage to occur.

[Mo]

+1 what Neil said.

[CalebD]

My A4 is raw water cooled so take this for what it is worth...

Your first pic shows the heat exchanger (HX for short). Your 2nd pic shows a water pump - which (I'm guessing) pumps anti-freeze through the engine block and on to the HX.
If I am not mistaken there should be a 2nd water pump which pumps the raw water through your HX and on to the exhaust.

When I run our A4 on the hard I always have to prime the raw water hose leading to the pump before it starts sucking consistently.

After 30 seconds of running (as Maurice suggested) there should be water coming out of the exhaust.

You are making progress Freddie.

[southcoasting]

My A4 is raw water cooled so take this for what it is worth...

Your first pic shows the heat exchanger (HX for short). Your 2nd pic shows a water pump - which (I'm guessing) pumps anti-freeze through the engine block and on to the HX.
If I am not mistaken there should be a 2nd water pump which pumps the raw water through your HX and on to the exhaust.

When I run our A4 on the hard I always have to prime the raw water hose leading to the pump before it starts sucking consistently.

After 30 seconds of running (as Maurice suggested) there should be water coming out of the exhaust.

You are making progress Freddie.

Thanks Caleb,
and how do you prime by just trying to put as much water in the hose prior to start I assume?

[CalebD]

Thanks Caleb,
and how do you prime by just trying to put as much water in the hose prior to start I assume?

Essentially, yes.

I have a "T" fitting in my raw water input hose so I set up a bucket outside the cockpit coaming and feed a 'drowned' hose to the input fitting on deck. If I use a dry hose the pump does not have enough 'head' to start the flow/siphon.

I'm sure the same applies if you are using a bucket in the cabin and using the raw water input hose after disconnecting from thru-hull fitting.

[Kelly]

In sniffing around this post I sense some confusion creeping in.

If I'm not mistaken, all we see in the photos are elements of the fresh water cooling circuit, which, apart from the heat exchanger, is completely separate from the raw water side.

I assume the pump we see is the added-on fresh water pump. I say assume as I have switched the functions of these pumps myself on several occasions so I can't really be sure. The pump we see seems to be obscuring the block-mounted pump located a bit lower down.

I mention this because it's possible you've been trying to feed water to the visible pump from your bucket. If this is the case, you would never see water coming out from the exhaust even if the fresh water pump was drawing water (actually circulating it through the bucket) as only raw water exits from the transom exhaust.

In the picture below of a raw water cooling setup, I've circled the standard raw water pump which is just under and aft of the distributor. The "water in" port is capped here with a red plastic cover. In your case, it should lead directly to the raw water through hull. The "water out" port feeds a red hose heading to the starboard side of the block. Again, in your case, this outlet should lead to the heat exchanger we see in your first photo. The water outlet from the block is on the top left of the photo and is also capped by red plastic. It's just above the open manifold exhaust flange. It too should be traceable to the heat exchanger. If you follow your hoses from the heat exchanger, you should be able to sort out the two circuits. One of the hoses will be traceable to the transom exhaust after having passed through any number of exhaust accessories (standpipe, muffler etc.)

I hope I'm not adding to the confusion. It's just that if I'm correct, you could be running your engine a long time without seeing water coming from the transom with this configuration. Don't forget that with your cooling system, you have two pumps, two impellers and two separate circuits: fresh and salt water.

[southcoasting]

I forgot to follow up on this but doing so now...

Thanks guys for the suggestions!

I had moved the bucket inside the cabin and placed it near the engine and it pulled water fine...As Neil suggested, I was asking the pump to do too much work...

To clarify, the pump pictured is indeed the seawater pump and not the freshwater (antifreeze) pump...

I got my engine starting great but now am in the process of slowing down idle (2400-2700 RPM at idle)...Which I think may be causing the engine temps to run high...Will try again tomorrow after adjust carb...

[positron]

My RWC system starts pumping water out the back before I can move from the starter switch to the back of the boat to look at it- 5 seconds or less, even after it gets partly emptied over the winter. With the boat in the water, there is enough pressure on the inlet that it does not need priming.

You might want to bypass your FWC system and just pump fresh water from the raw water pump through the engine. This would help isolate any clogs, once you replace the impeller. A problem with running the engine for very long without cooling water is that any rubber hoses on your exhaust system (typically after the muffler) are not designed for the high temperatures which will be present without cooling water, and can delaminate or melt.