Engine Overheating

[mbird]

doh! Mark is ahead of me!!!

One well earned Lakesailer for moi from Leroy methinks

[Guest]

doh! thats two this week!!! :

[Lucky]

LOL - now you are all getting in front of me !! lol !!!

Thanks Mark - as mentioned I think this is way down the back....

Adam - mate, they are KAD42a's. I have a couple of spare impellors on board - I bought a complete replacement service set of everything, so next service I will use what I have bought now, then replace those parts for next time if you see what I mean..

Everything on the boat was running fine when the engineer left last week, no problems at all and nothing getting hot.

[mbird]

I am presuming that the exhaust elbow is going to be a pain to get to..

Your a bit smaller than me Luke, so you should be able to reach it as I can, but it will be under the rear of the cockpit floor. I'm not sure of the relevance of that particularly though, as if the raw water pump is hot, there can't be any water going through it, so it stands to reason the pipe entering the exhaust elbow will also be hot. The problem must be the impellor or a blockage (or air lock) as no water is getting through the pump.

Ok, another silly thought. When the new impellor was installed, was it put in the right way, so the vanes are compressed in the right direction? The manual states the impellor should be installed with a clockwise rotating movement. This is to ensure the vanes are compressed i nthe right direction in the pumping part of the housing, otherwise when it turns, they will be pushing rather than pulling.

[senator]

will keep quiet, forgot about the turbo, why do you lot have to have all these flashy bits?

[mbird]

why do you lot have to have all these flashy bits?

They're needed to make that tractor juice go bang None of that "just add a spark" malarkey. This needs SCIENCE !

[Guest]

Mark...

I too agree that if the water pump is hot, being the first leg of the raw water circuit, it is most likely that this is where the issue will be (or in the pipe/inlet behind it). If thats hot, everything that follows must also be!

Dumb question to ask of luke...as a result of our water pump being above the waterline we have no seacocks for the raw cooling system? Is yours the same?. I only say this as I know of someone who had a service and promptly overheated because they had not opened the seacocks that the yard had shut to do the work.

If it was me...wanting to get fixed before the engineer came back...I would replace the impeller, re-prime by adding more water into the sea filter housing and give it ago...I suspect that it will be the first thing that he does.

lb : : :

[Lucky]

Mark...

I too agree that if the water pump is hot, being the first leg of the raw water circuit, it is most likely that this is where the issue will be (or in the pipe/inlet behind it). If thats hot, everything that follows must also be!

Dumb question to ask of luke...as a result of our water pump being above the waterline we have no seacocks for the raw cooling system? Is yours the same?. I only say this as I know of someone who had a service and promptly overheated because they had not opened the seacocks that the yard had shut to do the work.

If it was me...wanting to get fixed before the engineer came back...I would replace the impeller, re-prime by adding more water into the sea filter housing and give it ago...I suspect that it will be the first thing that he does.

lb : : :

Adam, there are no seacocks on the 310 - I know this as I asked the engineer when he started undoing things !! lol !!!

[Lucky]

Adam, how long was it before your's started to overheat, and did it overheat if it was just left in neutral ??

I've got the parents in law here for the weekend from 'up North, so I don't think I'll be allowed to go and play for an hour or two till Monday..

[Guest]

hi ya luke...why not take the parents in law planeing up breydon....

To answer the question..

the sensor that kicks the overheat alarm in is in the closed loop cooling bit...not the raw water route, so infact all the damage to the impeller can be done long before the engine itself reaches or goes over its normal operating temp.

On jupes, at about 1100 revs travelling about 5mph we would get about as far as the berney arms from Burgh castle (i suppose about 2 miles or 15 minutes) and the overheat alarm would kick off.

This just goes to show that without the raw water cooling, the closed loop water cooling is not enough to keep the engine at its operating temperature on its own.

Although there is no sensor/alarm to tell you if your raw water system is working, (the only way is to touch the water pump casing and exhaust elbow) these will heat up in a matter of seconds/minutes if the water is not flowing.

In other words...dont wait until the alarm goes off as it could be 15 minutes later...even in neutral.

We have had a couple of overheats where infact no damage was done to the impeller and we can only summise that the intake was temporarily blocked.

In these circumstances, our experience has been all that was needed was a re-prime (top up the sea water filter) and she was good to go.

Always check the sea water filter for tell tale bits of older impeller as this also could be the cause.

With regard to Marks point about fitting correctly in the right direction, I am reliably informed that it will not make a difference if fitted incorrectly because as soon as it turns, it will assume the correct position. When new, they are quite flexible so this is possible, but even so, fitting in the right direction is obviously recommended.

I think with all our experience of wearing out impellers, I may from this day forth, be called "impeller man!"

lb

[mbird]

I think with all our experience of wearing out impellers, I may from this day forth, be called "impeller man!"

lb

I think you've got quite enough names already Adam

[puddlejumper]

It looks from the photo like a jabsco pump when you check the impeller also check the wearplate inside the pump behind the impeller and the pump coverplate any bad scoring will not help the suction inside the pump the wear plate on the inside can be removed by undoing the screw that holds the swashplate on the side of pump housing, jabsco do a full repair kits hope this helps. Also if raw water goes through an oilcooler check that its not blocked by back fushing the cooler craig

[Lucky]

Hi Craig. When we replaced the impellor, we bought full kits which included the plate you are talking about and a new cover with o-ring - so would of thought this would be ok. As mentioned, I can't get down to the boat till either late tomorrow or Monday - I have been warned by the misses !!!

[mbird]

I can't get down to the boat till either late tomorrow or Monday - I have been warned by the misses !!!

But it's only at the end of your garden Luke! Just tell her you're going to prune the crocii or something, she won't know the difference.

[Lucky]

But it's only at the end of your garden Luke! Just tell her you're going to prune the crocii or something, she won't know the difference.

Nor do I mark !!

Right, the engineer just called and he is here tomorrow at 8am !! I just hope he can find the problem as the boat is totally out of action until its sorted. The power steering is controled from the affected engine...

I've tried everything that has been said with no luck. It looks like it is something a bit more complicated, like a blockage somewhere....

Adam, thanks for all your suggestions mate, I nearly took you up on your offer of coming over, but I really think its best for the company who serviced it to have a look.

On a slightly different subject, my friend that owns the Volvo dealership who said that I can order bits and pieces from (they are commercial rather than pleasure boat) gave me a dealers folder - so I've been going round the boat ordering little things that cost bugger all and really improves the look !! So far I've replaced all the bezels on the instrument panel, waiting for the walnut dash to arrive - I would of liked chrome, but the one I found was stupidly expensive. Replaced the volvo stickers on the throttles which have faded and turned silver over the 17 years and replaced various little bits and bobs..... Its starting to look much nicer now !! A lot of the bulbs have blown and never been replaced on the instrument panel so thats my next job.

So, fingers crossed that the engineer can sort the problem then we are off for a blast. Mark, I think I saw you mention that you'll be up Breydon on Saturday - if you decide to go, let me know, we'll meet you and anyone else who fancies it, up there. I really want to give the engines a full blast before Easter !!!

Again, thanks everyone for the suggestions on the overheat problem - When you have as little knowledge as me on stuff like this, its quite reassuring to have this forum to pop the question on !!

[Lucky]

The problem is no more !!!!!

BUT - we are not sure why it's gone. The engineer took the impellor out, including all the bits behind it then put it all back together (using a repair kit for bits that can be replaced) - re-primed the filter housing and we've been running for about an hour with no problems !!!

Fingers crossed that the problem has been corrected.

Out of interest, with regard to the re-priming of the filter housing, I've never had to do this before, even on my F33 - but on the phone call to the guy actually at Volvo he said this should be done especially after the impellors have been changed. It is certainly news to me, I know Adam knew this - but does anyone else who owns a Sealine, do you do it ? This wasn't the problem, but I'm glad I now know !

So, thanks to everyone for all the help on this topic (and others) - hopefully I'll be in a position to offer advice/help to others in the future !!

Luke

[mbird]

Glad to hear it's been sorted Luke, though I guess it would have been more satisfying if a problem had been identified?

I hadn't heard of re-priming either until I spoke to Simon (Plesbit). I shall certainly fill up my filters when she's dropped back in on Friday before I start up though

[Antares_9]

Glad it's rectified Luke.

Unless the pump is below the waterline it is good practise to prime it, as has been said particularly on a new impellor. Even the first few seconds before the water reaches it can be damaging to the impeller and if you get an airlock and it runs dry for longer then it can be terminal for the impeller. Not restricted to Sealines obviously.

[Guest]

Just a little tip when refitting your impellers pack them with Vaseline especially if they are not going to turn for a while. Do not use washing up liquid this will set. ( you know who you are ) The vaseline will keep the impeller free and will create a better seal when the engine first start. This will help the impeller pump air until the water in drawn up.

Jonathan

[jimbo]

Just a little tip when refitting your impellers pack them with Vaseline especially if they are not going to turn for a while. Do not use washing up liquid this will set. ( you know who you are ) The vaseline will keep the impeller free and will create a better seal when the engine first start. This will help the impeller pump air until the water in drawn up.

Jonathan

Washing up liquid is brilliant to use as a lubricant when fitting a new impellor. I do of course replace the cover and start the engine within a matter of minutes, so it setting has never been an issue for me

[Guest]

Washing up liquid is brilliant to use as a lubricant when fitting a new impellor. I do of course replace the cover and start the engine within a matter of minutes, so it setting has never been an issue for me

Hope it's Ecover Jim

[jimbo]

I'm not telling what type I use through fear of ridicule

[Antares_9]

I'm not telling what type I use through fear of ridicule

So, mild and green then Jim?

[mbird]

So, mild and green then Jim?

Just like his boat