Help, no water from my exhaust

[Quandary]

First, apologies to those who think I should be able to find the answer using the search button, it gives me more information than I could read in a fortnight and only some of it is relevant.
Boat was launched this morning, started engine (Volvo D1-30 with saildrive and indirect cooling) Started fine but only the odd drip of water from the exhaust. Removed impeller which was in several pieces, seemed to have collected the right number of missing vanes but half of one might be missing. Replaced and tried again, but only a little more water. Checked primary water filter for air leak but cover seal seemed to be holding fine as it was hard to lift the cover. Tried priming pump by pouring some water into the filter pot. Noticed that a drip had started where the rubber water pipe was connected to the impeller pump suggesting possible pressure there. Moved jubilee clip and added another to the joint. I am guessing that a piece of vane may stuck somewhere it should not be, the pipe joints are murder to undo so where should I look first. I am suspicious that the blockage might be at the vacuum valve but have no reason for this other than a sort of optimism as I know nothing about heat exchangers and all the other pipe joints are hard to get at. If it helps when I undid the impeller cover the second time water was flowing into the bilges at a considerable rate.
Any other suggestions? The owners manual I have is useless for fault tracing, I suppose they expect to take it to a workshop but I prefer to try to learn how to solve these problems.

 

[noelex]

First thing to check is that the sea water inlet is not blocked. This would account for the lack of water and because there is no water the impellor quickly disintegrates.

 

[Quandary]

First thing to check is that the sea water inlet is not blocked. This would account for the lack of water and because there is no water the impellor quickly disintegrates.

The water circulation was ok at lift out and the leg looked clean before launching. I was craned over and outside another boat, second boat out from the pontoon so well away from the canal bank in clean water. If it was a poly bag or similar it is unlikely to cover the holes in both sides of the leg and the prop wash when the engine was running should have shifted it. And the impeller housing is leaking a lot of water when the cover plate is loosened. Unfortunately the crane is away and not due back to mid October. I had put the impeller damage down to having turned the engine over dry for a few seconds a couple of times through the winter.

 

[Tranona]

Apart from the obvious of air getting in, you may well find bits of your impeller in the inlet end of the heat exchanger!

 

[Quandary]

Thanks Tranona, I will look there first thing in the morning. My attempt at checking for air leaks involved verifying that the top disc of the filter pot would not lift with the engine running, any where else to look.

What is it about boats, that they can not sit still for a few months without developing a problem?

 

[philip_stevens]

Take the water injection/exhaust elbow off (or at least, the water inlet pipe) and check that the water inlet is not blocked with carbonised salt.

On our 2003, the hole should have been about 20mm but was only about 3mm in size.

Hence, water was absolutely pi55ing out of the pee hole on the hull side, and very little out of the exhaust.

 

[noelex]

The water circulation was ok at lift out and the leg looked clean before launching. I was craned over and outside another boat, second boat out from the pontoon so well away from the canal bank in clean water. If it was a poly bag or similar it is unlikely to cover the holes in both sides of the leg and the prop wash when the engine was running should have shifted it. And the impeller housing is leaking a lot of water when the cover plate is loosened. Unfortunately the crane is away and not due back to mid October. I had put the impeller damage down to having turned the engine over dry for a few seconds a couple of times through the winter.

The sail drive water inlet, or seacock, can still be blocked. See this post.
http://www.cruisersforum.com/forums/f54/no-raw-water-from-sail-drive-seacock-32846.html
You may be right about another cause, but its always worth checking the basics.
A few seconds dry should not destroy the impellor and if you have got most of the impellor bits out any small amount left may reduce the water flow but should not block the water supply completely.
Good luck.

 

[Quandary]

Thanks Noelex, I have read the thread you referred me to and will keep it in mind. My tendency to discount the leg being blocked was because of the volume of water pouring in when I slackened the cover plate the second time, also the boat spends more than half its time in fresh water which tends to be very effective in combating marine growth. A few days in the canal is regarded as better than scrubbing around here. I must investigate if there is an actual cock on the pipe rising from the leg, I have never noticed one and my manual does not refer to it but it would seem to be a necessary safety feature, (at present, if I want to work on the impeller I break the syphon by taking the cap off the filter above the engine) unfortunately that side of the engine and leg is in the darkness against a fixed bulkhead without easy access.

 

[bendyone]

Could be barnacles in the water inlet in the leg. try connecting a dinghy pump to the pipe and blowing out through the inlet.

 

[scottie]

Suggest you check that the lid for the strainer is on the correct way it may not seal if not
Allowing a air leak

There should be a ball valve on the water intake check that it is open

The legs do suffer from shell fish growth although the mix of fresh and salt should sort this

The main inlet is the hole at the bottom not the strainer at the front

The fact thatnthe impeller is burnt out would suggest lack of water rather than blockage after the pump

 

[EuanMcKenzie]

jury rig an alternative supply

old trc ik I was shown for running your engine out of the water and helps me for testing prior to launch.

Is there a hose between the water inlet and the raw water pump. If so can you safely remove it . If you can put a length of garden hose inside and do up with jubilee clip. Fill a bucket with water and place other end of hose in bucket.

start the engine.

If the bucket is higher than the engine it should prime and you should see the level drop in the bucket.

This will at least show which side of the water system is blocked.

May be a useless idea if you can't safely isolate and connect a hose, if so apologies i'm no expert on sail drives

 

[ostell]

Just had similar 2 days ago. Changed impeller etc but no change. Panic call to dealer who suggested that it was calcium build up because of lack of use (replacement knee last year). Took off hoses after impeller and lo and behold very crunchy pipes. Cleared out pipes and problem gone.

 

[elton]

I once had no water coming from the exhaust, so I hung myself right over the side with a long handled broom and gave the inlet a good brush. End of problem.

 

[Quandary]

Thanks again.
Update on my problem. Got a couple of small pieces of impeller blade out of the heat exchanger. Now got water splashing out of the exhaust but as well as that there is a small steady stream of drips from the back of the impeller. It is not from the hose connection as I had suspected but must be a crack in the pump body. Can not get behind the pump to see anything and can not feel anything out of place so I suppose the pump will have to come out. Do you just undo the four bolts and pull it forward?
I thought I had got rid of all the water from the raw water side before the frost but there must have been some lodged in the pump.

 

[Ceejay]

Oh dear, might be about to get expensive!...

I have one of these engines but with shaft drive, so I'm watching with interest...good luck.
CJ

 

[Bosun Higgs]

Most raw water circulation pumps have a drainage hol underneath to prevent water getting intoi the engine if the shaft seal becomes tired. Your pump may just need a new seal which is a simple diy job.

 

[Quandary]

Most raw water circulation pumps have a drainage hol underneath to prevent water getting intoi the engine if the shaft seal becomes tired. Your pump may just need a new seal which is a simple diy job.

Yes, I think you are right, I have the impeller out again and and I suspect the front sealing ring at the back of it, perhaps its been damaged by the vane fragments. It seems to be sitting back farther than I think it should. All the skin is off my knuckles but I can not get the two hoses off to take the pump out, and the space available is too tight for gloves, I presume I have to get the pump out to get at the seal? There are two seals either side of a bearing and an O ring shown in the parts diagram on Volspecs. site. I presume I should replace all the seals.
It would be 'a simple diy job' as you suggest if the engine was not in a b***dy boat.

 

[Twister_Ken]

Yes, I think you are right, I have the impeller out again and and I suspect the front sealing ring at the back of it, perhaps its been damaged by the vane fragments. It seems to be sitting back farther than I think it should. All the skin is off my knuckles but I can not get the two hoses off to take the pump out, and the space available is too tight for gloves, I presume I have to get the pump out to get at the seal? There are two seals either side of a bearing and an O ring shown in the parts diagram on Volspecs. site. I presume I should replace all the seals.
It would be 'a simple diy job' as you suggest if the engine was not in a b***dy boat.

My last boat was like that. Local engineer replaced the seals in no time at all. I suspect there are one or two tricks of the trade which they don't pass down to us mere mortals.

 

[[448]]

Check the condition of the pump shaft when you get it out. Any roughness or scoring will soon wreck the new seals. Get a new shaft if it's doubtfull.
Dave

 

[scottie]

Make sure you have turned the water off

If you can get the pump off speak to Mack engineering hillington Glasgow if you cant get the bits from crinan