Volvo Penta MD22 coolant headsup

[Heckler]

Again a repeat headsup for those with MD22s, this prompted by watching demonboy on youtube and his woes with his engine. When he removed his ALUMINIUM head you can see where the head had corroded from the water way through the aluminium. A lot of people think antifreeze is just that, it isnt, it is also a corrosion inhibitor. People, especially in warm climates, get a small leak or dont change their coolant, they top up with plain water and them slowly the coolant loses its inhibitor properties and the alminium heads start to corrode!
Stu

 

[NUTMEG]

Good advise Stu, in addition I flush the seawater side with fresh water from a hose pipe and then add anti-freeze to the seawater (raw) circuit too. I find that at tickover, the hose more than keeps up with the pump just pouring into the top of the Vetus strainer. Sea cock closed of course.

This might seem a bit overkill but last spring I had cause to remove the heat exchanger and found a very badly corroded brass plug. Dezincified and red coloured, it sheared off like a carrot when I tried to remove it. I was surprised there are no anodes in the raw water circuit and often think about fitting one or two where the two brass plugs are fitted.

So, adding antifreeze/freshwater solution at least should slow any corrosion on that side of the cooling system.

Happy New Year, by the way

 

[Yngmar]

Deja vu? Not that isn't worth repeating

 

[RichardS]

Deja vu? Not that isn't worth repeating

Ah .... that's explains it. As I was reading Stu's post I was thinking that the last 3 days since I first read the post seemed to have passed very very slowly.

Richard

 

[Heckler]

Deja vu? Not that isn't worth repeating

did it happen to you? ive got my spare, as in the pbo article, sitting in the garage!
Stu

 

[Yngmar]

did it happen to you? ive got my spare, as in the pbo article, sitting in the garage!
Stu

No, all good so far and hopefully will remain that way for a long time! Haven't got a garage to store spare engines in, but read your article with interest. Cheers Stu

 

[Heckler]

No, all good so far and hopefully will remain that way for a long time! Haven't got a garage to store spare engines in, but read your article with interest. Cheers Stu

i must say, mine has done a lot of hours, but it still starts first time, no sewing machine! burns a bit of oil, maybe a litre a season, its as clean as a whistle, am well happy with it.
Stu

 

[Yngmar]

The sewing machine sound on mine turned out to be the Bosch VE injector pump, and seems to be within normal range for it. Not burning any oil either. There's some corrosion from when PO/broker left the raw water pump leaking all over the engine, which I've tried treating in situ (not very successfully) and just sprayed with some Waxoyl for now. Oh and I probably should do the timing belt dance some time.

 

[RodZ]

Hi, New here and I apologize if I am not doing things right.
I have an MD22L, Last week I changed out the raw water impeller and while I was at it, I opened the heat exchanger ends and cleaned them up, I did not pull the heat exchanger out. I also drained the coolant and replaced it with a new one. Run the engine for 30mins and everything looked good, expansion tank filled between Max/Min.
The next day I went out and noticed that the tank had emptied and could see small drips dripping on the oil filter. I cracked the cap open on the tank some coolant returned back in the tank but topped it up again.
At ths point, I have put 8ltr of coolant in the system and the tank is below minimum,drip is still going but no other signs of leaks anywhere.
Any ideas?



Again a repeat headsup for those with MD22s, this prompted by watching demonboy on youtube and his woes with his engine. When he removed his ALUMINIUM head you can see where the head had corroded from the water way through the aluminium. A lot of people think antifreeze is just that, it isnt, it is also a corrosion inhibitor. People, especially in warm climates, get a small leak or dont change their coolant, they top up with plain water and them slowly the coolant loses its inhibitor properties and the alminium heads start to corrode!
Stu
[/QUOTE]

 

[RichardS]

Hi, New here and I apologize if I am not doing things right.
I have an MD22L, Last week I changed out the raw water impeller and while I was at it, I opened the heat exchanger ends and cleaned them up, I did not pull the heat exchanger out. I also drained the coolant and replaced it with a new one. Run the engine for 30mins and everything looked good, expansion tank filled between Max/Min.
The next day I went out and noticed that the tank had emptied and could see small drips dripping on the oil filter. I cracked the cap open on the tank some coolant returned back in the tank but topped it up again.
At ths point, I have put 8ltr of coolant in the system and the tank is below minimum,drip is still going but no other signs of leaks anywhere.
Any ideas?

Welcome to the forum.

I'm not totally sure what the question is, but if your cooling system was fine before you worked on it then the loss of coolant is a result of something you have not quite replaced properly. The obvious culprit will be the H/E end caps and the seals/gaskets/O-rings in the caps being damaged, mis-positioned, under-tightened or over-tightened. When you check these fittings again, make sure that you smear plenty of silicone grease on the O-rings/gaskets/seals as this will allow them to bed into position and assist them to seal properly.

In some systems, poorly fitted end caps will result in coolant going out with the sea water through the exhaust as well.

Richard

 

[RodZ]

Welcome to the forum.

I'm not totally sure what the question is, but if your cooling system was fine before you worked on it then the loss of coolant is a result of something you have not quite replaced properly. The obvious culprit will be the H/E end caps and the seals/gaskets/O-rings in the caps being damaged, mis-positioned, under-tightened or over-tightened. When you check these fittings again, make sure that you smear plenty of silicone grease on the O-rings/gaskets/seals as this will allow them to bed into position and assist them to seal properly.

In some systems, poorly fitted end caps will result in coolant going out with the sea water through the exhaust as well.

Richard

Hi Richard,

Thanks for your reply,
I am pretty sure there is a small drip of coolant dripping on the oil filter which must be coming from the water pump. I have read it is coming from a weep hole (tell tail) on the water pump to indicate a seal is leaking. I also read that the seal cannot be replaced but the entire pump needs to be changed out, Is this correct?
The loss of coolant is still a mystery, but I agree , I will check the H/E caps again.
Another thing I have noticed, is the hoses that run to the water heater and back do not have shut off valves on them. Is this normal? If I had a burst hose or damaged water heater that would mean the engine cannot be run at all. I will install a couple of valves to make sure I eliminate this issue.

 

[Yngmar]

If your oil filter is where my oil filter is (MD22L-B), then I think you might be right about the leak being at the water pump. Parts4engines has a replacement: Volvo Penta MD22 Water Pump

You'll have to remove the timing belt to get at it. The Volvo service manual tells you how and the Haynes book for the Perkins Prima (Austin Montego) tells you how to do it without any special Volvo tools.

Our calorifier hoses also do not have valves on them. I did idly wonder if shutting them off (if they were there) stops the coolant circulating through the engine or if there is an internal bypass.

 

[RodZ]

If your oil filter is where my oil filter is (MD22L-B), then I think you might be right about the leak being at the water pump. Parts4engines has a replacement: Volvo Penta MD22 Water Pump

You'll have to remove the timing belt to get at it. The Volvo service manual tells you how and the Haynes book for the Perkins Prima (Austin Montego) tells you how to do it without any special Volvo tools.

Our calorifier hoses also do not have valves on them. I did idly wonder if shutting them off (if they were there) stops the coolant circulating through the engine or if there is an internal bypass.

Good point about the circulation of the coolant if valves are installed and shut. Will take a good look at that system before I fit the valves.
Thanks