How do you clean the heat exchanger?

Mike k

Well-Known Member
Joined
28 Mar 2011
Messages
1,307
Location
Rossendale
Visit site
Hi all, my heat exchanger has two interconnected cylinders - the top larger cylinder where sea water flows through the pipes and cools the freshwater coolant for the engine and the lower smaller cylinder where sea water cools the oil.At each end there are circular end caps so 4 in total.

I have had differing solutions e.g rodding through , jet washing, specialist treatments and today someone suggested not to rod in case of damage to the delicate tubes.

Firstly how often should this be done realistically- (my engine is 6 years old 300 hours) and what is the panels view on the easiest and most effective cleaning technique or your experiences.

I am in the North West so if there are some specialist cleaning companies around here I would grateful to learn of them.

Thanks very much for any info

Mike
 
Hi Paul thanks for that, looks really intersting - how do you apply it- can it be done on situ by flooding it into the hose that goes in or do you have to take the unit out and soak it externally to the boat?

I filled a large bucket with a solution of Rydlyme and connected a pair of hoses to the cooling system, one at each end. I fitted a submersible bilge pump to one hose and dropped it into the bucket, the other returned the solution to the bucket. Switched it on and left it running for a few hours.
 
sounds like you have mercruiser diesels I had two in my last boat & found that the anodes used to break off inside the heatexchangers so i used to take the end caps off mine and rodd them with a thick brazing rod which is soft and shouldnt damage the core (unless your rough with it) I did mine at the end of the season when i serviced the engines before layup then filled the system with antifreeze mix & they stayed prety clean over the 5 years i ownend the boat

i used to replace the anodes in spring as i wasnt sure if the antifreeze would have any effect on the anodes performance
 
As if by a miracle I think I have attached a before and an after picture for a mildly crusty D6 intercooler treated for one hour wirh Rydlyme.

Bloody hell it worked ( posting pictures that is ) .

It literally came up like new.
 
I filled a large bucket with a solution of Rydlyme and connected a pair of hoses to the cooling system, one at each end. I fitted a submersible bilge pump to one hose and dropped it into the bucket, the other returned the solution to the bucket. Switched it on and left it running for a few hours.

I've used Rydlyme and this method as well (using a Gulper 220 pump) but a point to remember is to remove any anodes that may be in the sea water cooling system and fit blanking plugs instead. You'll know when the liquid has done its job because it will stop frothing.

Have fun.
 
We are using both the soaking method as in soaking it in a bath of solution 50 :50 with water or 25:75 rydlyme/water when the components are dismantled anyway and also recirculating it around the seawater system of an engine with the impeller removed with a continuosly running pump fed and return to a bucket.
 
Domestic descaler powder from the plumbing section at B&Q works for me, and costs about £5 for two sachets that will easily sort two coolers without full dismantling.

I remove the anodes as a precaution, but this stuff doesn't seem to make them fizz.

On my TAMD60C I remove the top of the after cooler and drain plug on the water pump. Once drained pop the plug in finger tight, and pour the diluted powder mix in until the level sits above the tubes of the after cooler. Leave it and watch the built up crud fizz and bubble away, and after two hours drain down and flush briefly before reassembling the system then start and let the seawater finish the flushing.

I have made a special fitting using a 22mm copper str connector hat fits exactly into the o rings on the heat exchanger to fill this and the gearbox oil cooler. Again 2 hours and job done, £10 per engine.
 
Top