How to remove heavily scaled closer coolant system

[mctaggart]

Hello

I have got a Mercruiser 4.2 D-Tronic in my power boat which i have recently purchased, doing some engine work and its come to my attention that the closed coolant system is heavily caked with what looks like old thick crystallised deposits of coolant. The pipes are "crunchy" when you squeeze them and no doubt this is probably running through the entire cooling system as well as the heat exchanger.

I am not having any problems yet with over heating, but this is no doubt a problem that can be prevented before it gets too bad.

I need some kind of flush which i can run through it to remove all this buildup, does anyone have any recommendations on what to put through it, maybe home brew? I am a bit of a sceptic to buying off the shelf bottles of radiator flush which is like the old snake oil!

What do you guys use?

Thanks

 

[kashurst]

rydlyme is well regarded and works. However if it was me I would take it all to bits, stick it all in calgon to get the gunge off, thorough clean and inspect to look for any dodgy pipes etc, and then back on. Then you know its all gone.

 

[boatingdave]

rydlyme is well regarded and works. However if it was me I would take it all to bits, stick it all in calgon to get the gunge off, thorough clean and inspect to look for any dodgy pipes etc, and then back on. Then you know its all gone.

or a combination of the two approaches? Rydlyme does have a good reputation although most 'cement cleaners' will work (not sure if any of them should be discharged out though). Often the heat exchangers get clogged too and these can be troublesome to get off and put back on intact. Thats from experience. .

 

[mctaggart]

Rydlyme seems to be for the salt water side of the cooling system, of which mine looks ok, I need somthing for the closed cooling system which the antifreeze sits in. I dont think Rydlyme will be any good for that as it seems to be based around disolving salt deposits.

 

[boatingdave]

Rydlyme seems to be for the salt water side of the cooling system, of which mine looks ok, I need somthing for the closed cooling system which the antifreeze sits in. I dont think Rydlyme will be any good for that as it seems to be based around disolving salt deposits.

Good point. However whats in there if its not scale? I would have thought the anti-freeze would have additives to prevent deposits? Honest answer is I've never come across scale build up on the closed side so just thought it could still be deposits from the water. I'm sure someone on here will know.

 

[oldgit]

Rydlyme seems to be for the salt water side of the cooling system, of which mine looks ok, I need somthing for the closed cooling system which the antifreeze sits in. I dont think Rydlyme will be any good for that as it seems to be based around disolving salt deposits.

Pretty sure it is for both.
Did use Rydlyme on raw water system using a little pump system.But the only thing that finally cured a chronic high temperature reading was removing the heat exchanger and marinating it in neat B & Q brick cleaner for 30 mins.
With copious amounts of rinsing afterwards.
Have yet to refill with antifreeze