Engine flushing - what to use to clean up system.

[Gwylan]

The water pump died over the weekend after a slog from Le Havre to Fecamp.
It's a fresh water cooled Volvo 2003 with 2,500 hours on the clock, but [fingers crossed] runs like a dream. Well except for the cooling issue.

Anyway, we had a spare pump and replaced it, the impeller and belt to have a nice rennovated system.

But the cooling water that was left was a pretty dreadful brown - orange colour.

Since we are now home and have time on our hands what do people recommend for flushing through the the fresh water side of the cooling system?
Any suggestions for a source on a replacement belt?

 

[maxi77]

Probably worth a treatment with Radflush then back flush and fill with approprate diluted anti freeze

 

[prv]

But the cooling water that was left was a pretty dreadful brown - orange colour.

What colour coolant ("antifreeze") do you have in there? Volvo currently have a green type and a yellow type; I think the yellow is newer but we have the green. When we first got the boat she had some unidentified purple type. For all I know there's another brand which is orange and that's what you're seeing?

Pete

 

[Bobc]

I suspect the orange colour is pink antifreeze with a bit of rust colour added.

 

[VicS]

There is a 2part Radflsh if you think the system is very corroded or especially if its scaled up.

Otherwise the single pack version for a quick clean up is called Speedflush.

Both marketed by Holts and readily available.

The correct antifreeze for the engine is the conventional low silicate (sometimes called inorganic acid) type used in older cars etc. rather than the long life or organic acid (OAT) type. They should not be mixed

There is no universal system for the colours.

 

[Gwylan]

Thanks for that. Appreciate the heads up on the choice of silicate or other.

We have drained out at various times in the past and refilled with what started out as pink'ish a/f. Very quickly it gets pretty orange, or even a rusty colour. Hence the plan to try and give the whole system a good clean and then add some appropriate coolant. Especially now we have a new Volvo [gasp, more than my entire car is worth] water pump.

 

[nigelmercier]

Flush with Oxalic Acid for 20 minutes, allow to cool, drain.
Rinse with water for 20 minutes, drain.
Rinse with water for 20 minutes, drain.
Rinse with water for 20 minutes, drain.

 

[laika]

This may be of interest:
http://www.ybw.com/forums/showthread.php?401911-Mucky-coolant

 

[nigelmercier]

This may be of interest...

"The authorized Yanmar service guys I know told me that they have to use a system cleaner..."

For details of what this cleaner is, see my Post 7 above.

 

[laika]

For details of what this cleaner is, see my Post 7 above.

I'm not questioning you. I was deeply unhappy with how my experience turned out, wish I hadn't pressed the point and just sorted it out myself...

 

[Tim D]

Personally I wouldnt use radflush, go for the volvo penta 2 pac engine cooling system flush, its not cheap but if you do it properly you will be amazed how clean the system comes up, you will have to order it tho, refill with as mentioned earlier, any universal antifreeze with corrosion inhibitor will do the job 50/50, keep some 50/50 on board for topping up, then drain freshwater flush and refill every three years, this will prevent your build up of crud in the system.

 

[nigelmercier]

... 50/50 ...

If buying the stuff that needs to be diluted, remember to use de-ionised water.

As an aside, one of my friends in the Canary Islands was most amused that I was buying antifreeze, and indeed able to buy it. They do a different type there, for temperatures around freezing rather than the normal -18C.

 

[VicS]

If buying the stuff that needs to be diluted, remember to use de-ionised water.

Water with a low TDS is OK so not always necessary to use deionised water. Many of the VP manuals have a guide as to what is an acceptable water analysis. Trouble is its not something you ordinarily know much about.

I have analysed our water supply at home, although it can change, and in some locations significantly during the course of the day.

I'd not know the analysis of the water at the boat yard though.

If in doubt probably sensible to buy the ready diluted stuff.