hi all, crossing the tweed bar on a big outgoing tide, we had 2 steep little waves hit our stern and i think that may have caused my engine to overheat. the seawater in my exhaust was only trickling out there was a hell of a lot of white smoke pouring out.
any how, a long story short, next day i checked oil level, seacock filter and impeller which was all ok. i had to fill my coolant header tank. my volvo penta d1-30 fired up straight away pumping heaps of sea water, after running a few minutes it started to blow white smoke. my coolant tank was empty again, re filled it then on starting engine again i noticed all my coolant going out my exhaust.
i am going to start with looking at the heat exchanger other wise i guess its a head gasket or even worse.
this sounds a little like andy"s honey i blew up my engine. well, any ideas?

Sound like a head gasket
The up side is you can give the valves a clean up and reset them and fit new cakve seals
What a lovely xmas present for your boat
Merry xmas

Given my current struggle with a seized motor that had only sat around for a while, would our OP not be recommended to unscrew the injectors and squirt some oil in the cylinders to prevent corrosion until he gets the head job?

I thought my head gasket was blown but when I pulled the head off the gasket looked OK.
It might just be water in the cylinders caused by the waves pushing seawater up the exhaust through the open exhaust valves into the cylinder. The seawater can leak past the rings into the crankcase.
It might just be a matter of about 5 or 6 oil changes if there is water in the oil
The smoke could just be the steam from the water decarbonising the engine.
People on here know a lot more about engines than me but it might be worth seeing if runs ok if the oil looks good.

That it starts OK leads me to believe the head gasket might be OK. If there is no water in the oil that would also lead to it not being the gasket.
It is also easier to check the heat exchanger than the head gasket.

Having to top up the header tank and the white smoke would indicate to me it's a pin hole in the headgasket. I think you should follow HG02's advice.

i ran engine yesterday for 15mins,it ran as sweet as a nut without blowing any smoke. BUT i watched 5ltrs of coolant pour out my exhaust. i cant imagine that much coolant loss could come from a head gasket or cracked head. im thinking maybe a corroded heat exchanger. i guess the only way to find out is to get the toolbox out and have a look around.
thanks guys

Sounds like it would be a good idea to start at the heat exchanger. If you lose the coolant the engine is going to get hot and generate steam-"white smoke".

well good news i guess, i found a corrosion hole about 3mm in the exhaust manifold allowing the coolant to to enter the exhaust. the exhaust manifold and heat exchanger is combined as one casting. im hoping i can get it welded as it looks like an expensive part from good old volvo, any thoughts out there on using an epoxy?
cheers

Where are you situated? If you have the part off the boat and have easy access to the hole it's easy to weld. Alloy is easy to weld with a mig welder and argon. My machine is still set up from welding an aluminium support yesterday. Devcon or Jbweld will do the job too but make sure the alloy is dead clean [pressure pack brake cleaner].

If you clean it with brake cleaner and are going to weld it I would read this.

www.brewracingframes.com/safety-alert-brake-cleaner--phosgene-gas.html

Holy crqp Jolene that's intense.

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Jolene said..
If you clean it with brake cleaner and are going to weld it I would read this.

www.brewracingframes.com/safety-alert-brake-cleaner--phosgene-gas.html

If your going to glue it use the brake cleaner. It evaporates almost instantly, certainly does not sit around in droplet form. If your going to weld, scrub the area clean with a stainless steel brush.

The only danger is the alloy gets bloody hot but there are no visible signs like with steel. Takes a while to cool and its easy to forget which part you just welded!

Wear safety glasses when using brake cleaner.

I think I will take it to my local engineering shop for advice. Mark has many years expierence in engine recondition. I will certainly let him know about the danger of brake cleaner. The hole is easy to get at but the metal alloy is thin so I may need to glue. Any recommended products out there. Not a good week to get things fixed or gaskets ordered.

When I repair things like corroded aluminium castings and cylinder heads, the corroded component of the aluminium needs to be removed. I usually do this with a die grinder like a dentist grinds decay out of a tooth. This can lead to that 3mm hole your fixing ending up 10mm or bigger. Sometimes on alloy castings, due to the porosity and often impurities, it can become very difficult to weld and in the end you wished you had just bogged it with Quick Steel. Again if you use Quick Steel ,remove as much of the corrosion from around the hole and have a shinny abraded metal surface out to around 3 x the hole size. Use a die grinder or Dremel tool with a cutter burr and not a stone.

I used Quick Steel to repair an external crack(50mm long) into the water jacket of a Diahatsu Applause, The crack was opened out with a die grinder and cut back to shinny metal around it. Quick Steel was pressed into place with my thumb. The motor would have needed to be pulled to weld it. The car did 200,000 kms on that repair and was sold. Quick steel is also good for holes in fuel tanks, plastic or metal.

I'm buying some of that quicksteel just in case

thanks jolene and everyone else, if its not recommended to weld ill look at quick steel, 200,000 kms sounds almost permanent, maybe i should quick steel it as i agree with what you said about wishing i hadn't welded it. it is quite thin

Is the corrosion just in the one small area or more widespread? This is not a crack, hence something like Quick Steel is not going to repair all the corrosion. Personally I would want my engine to be reliable. If you are crossing bars, etc, a dodgy repair is not a good idea.

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Yara said..
Is the corrosion just in the one small area or more widespread? This is not a crack, hence something like Quick Steel is not going to repair all the corrosion. Personally I would want my engine to be reliable. If you are crossing bars, etc, a dodgy repair is not a good idea.

If that's the case and you don't think the dodgy repair or welding is a good idea, you throw the part in the bin and get a brand newy.

Sometimes you can find corrosion is localized in one spot due to Cavitation.

I'm a fan of Devcon but the cost is getting a bit out of hand and have been using a fair bit of JBweld. This is an interesting video.

Interesting video , thanks for posting it up. I never have used the Quik Steel in a glue, I have only used the plasticine putty stuff that you kneed. It has a short working time and can generate a bit of heat during the reaction.