Flushing the FW side

[Strait Shooter]

I noticed over the summer that my engine (Perkins M-50) started running hotter than it had been before by about 5-10 degrees. While checking things out I felt some semi-coagulated substance in the heat exchanger as well as congealed antifreeze at a hose bib or two. While operating temperature is still within acceptable limits, it's time.

I've read everything I can find on this, but I'd still like to ask for some advice. The Plan is to remove the thermostat, flush heat exchanger and entire FW cooling system with Ridlyme (I think?). I'd like to mix some ridlyme and water into the system and then run it up to operating temps. After the engine cools again I will begin a series of distilled water flushes, I believe three as a minimum ought to get me close.

I'm also replacing some original hoses and clamps, and probably the thermostat as well.

I'll also remove the heat exchanger tubes and inspect them at this time......right? If I see any build up still, I'll take it to a radiator shop, if not, I'll clean it up and put it back.

Then a fill with the appropriate anti freeze, and distilled water at a 50/50 mix, and a run up to temp again.

I saw it mentioned in the threads of a Maine Sail method for flushing, but it isn't on his web site, and I can't find it here either. Anyone know where it is, or what the procedure was?

I appreciate any responses, thanks!


John

[a64pilot]

One way is to go to Walmart or any parts car parts store and buy a flush kit. All it is is a T fitting that a garden hose connects to, designed to go into a heater hose.
Install "flush kit" in hose that goes to water heater, remove thermostat and re install housing, open drain at engine block and or heat exchanger, turn garden hose on and run engine until nothing but clean water is coming out, since entire cooling system is under pressure from garden hose, you can't get an air bubble and hot spot and the whole thing flushes into the bilge of course and is pumped out. Running the engine ensure all the water is circulated, reason you removed the thermostat, I replace the T stat with a new one, keep the old as a spare.
Being extremely poor and lazy, I remove the rad cap and put a hose in there using my hand to control how much water goes into the engine, but otherwise the same.

I try to avoid chemicals in the fresh water side of the cooling side, so far I have never had to resort to chemicals, flushing alone has done the trick

[Strait Shooter]

Over a thousand views and ten responses about getting bird **** off your boat, and 1 response and fifty views about a mechanical issue that a lot of people should be thinking about with winter coming on.

We'll just sweep this under here, no one will ever know.

[IdoraKeeper]

well it got me thinking...I gotta paint in there so maybe I should emulate your example and flush mine too. There's alot of old antifreeze and even a bit of rust when the cap is open but the coolant in the overflow tank is a nice green. Dont forget to get a gasket before you pull the Thermostat.

[Wainui]

Don't forget the raw water side. I just used swimming pool acid diluted down and ran that through the system.

[a64pilot]

I would not go back with 50/50 antifreeze. Reason is there will be a lot of water left in the system and you will end up with a lot less than 50% antifreeze. Personally I run a lot more than 50% for additional corrosion and water pump lube protection. A rich mix of antifreeze will not absorb as much heat as a 50/50 mix, but there is a lot of reserve capacity in the system so that should be no issue.

[Strait Shooter]

Those are all good points that I hadn't thought about, thanks everyone.

I think mine might be pretty cruddy if my past experiences with the PO maintenance program hold true.

[ranger58sb]

Originally Posted by Strait Shooter

I've read everything I can find on this, but I'd still like to ask for some advice. The Plan is to remove the thermostat, flush heat exchanger and entire FW cooling system with Ridlyme (I think?). I'd like to mix some ridlyme and water into the system and then run it up to operating temps. After the engine cools again I will begin a series of distilled water flushes, I believe three as a minimum ought to get me close.

Cummins/Fleetguard makes a product called Restore for flushing the freshwater (antifreeze) system. Probably other makers offer something similar.

The general procedure is to drain the antifreeze, inject Restore (or whatever), run the engine to temp, drain, inject fresh water, run the engine to temp, drain, fill with fresh antifreeze at the appropriate dilution.

For our mains, I think (from memory) this is a 600-hour service item.

Rydlyme, Barnacle Buster, and Triton Marine offer products suitable for flushing the raw water (sea water) system.

There are two general procedures. One is to inject solution, let it sit, flush with fresh water, let it sit, then put the system back in service. The other procedure is to create a loop, inject the system, but keep it running back to a capture vessel, continually doing that... maybe running the engine up to temp once or twice... then flushing with fresh water.

I haven't done my raw water systems, so all that last is just from reading.

-Chris

[HappyMdRSailor]

Exactly what do the 10 bird **** responses say???

This seems too technical a subject for this forum...

Ya got some good answers... Your FW system is just like a car... I personally DO put the flush chems in the FW side, heat it up, and flush it out...

[clyde]

on the cooling system, i have a 6cyl, old volvo[with 10,000 hrs] i set it up so i can flush it with fresh water, then when i shut down the main, it flushes the genset too...if i don`t use the boat for more than 3 or 4 days, it`s [always] flushed before i turn it off! it`s the salt water that causes the problems in the coolers, zincs, etc...i clean my 3 coolers every 4 or 5 yrs, in a 4/1 mix of normal water, and mauratic acid, clean all the gaskets, or buy new ones, and put teflon grease on the old ones so they are ready for next time...i also use cat permanent type anti freeze, which has an additive available to extend it`s life, and has the stuf in it to stop the problems with cyl liners/corrosion...i save old thermostats just in case! you can also clean out the holes in the cooler with wood dowels [carefully, i never use welding rods]...clyde

[a64pilot]

Clyde has a good point, if your engine is wet sleeved, make sure your coolant has the additive for cavitation so you don't end up with pin holes in your cylinders.

[MarkSF]

I'd like to suggest Valvoline Xerex G-05 as the best replacement coolant that is relatively easy to find. It is compatible with all other coolants, but has the long lifetime of an organic acid corrosion inhibitor. It's actually a hybrid chemistry with OA and some silicate.

When I wanted to flush the TR8, I just used the oxalic acid crystals that I already had for cleaning teak. Made a solution in a bucket, and ran the engine on it for half an hour. The fact that about 4 leaks appeared reflected the state of the cooling system at the time!

If you look at the ingredients of the high street cooling system flushes, they are mild acid solutions.

I actually found a GM service bulletin for removing dexcool deposits with an oxalic acid solution.

[a64pilot]

Originally Posted by MarkSF

I actually found a GM service bulletin for removing dexcool deposits with an oxalic acid solution.

I wondered if Dexcool had ever been in it when I read the finding some kind of congealed something in the cooling system.
I've never had bad luck with Dexcool, but I've never mixed it either. Still have the wife's CTS-V that has Dexcool, need to get around to flushing it I guess.

[jimbunyard]

If you have the heat exchanger with the rubber boots with 2 clamps on each end, make sure when you go back that the heat exchanger protrusion on each end is the same, that the sealing surfaces on both the boot and the exchanger are clean, and the smaller clamps which seal the raw water through heat exchanger from the freshwater in the engine are good and tight, Perkins may even recommend some type of sealant on the area before assembling. I use a light smear of silicone on the boots of my MD2020, which has the same type system.

With a r/water pump in good shape and a slightly high level of exhaust system back pressure, less than perfect sealing there can allow raw water to be pumped into the freshwater side. (Ask me how I know).

Also, the big holes on the heat exchanger go down, the tiny hole is a bleed hole and goes up.

[Strait Shooter]

I'm going to use Prestone's flush product.

I didn't know about the DexCool issues before today. Yes, I did indeed find coagulated gunk when I stuck my finger in the radiator cap hole. More telling is that the thin film on the inside of the radiator cap was black.

Prestone's product states that you can use it without removing the thermostat. I don't have a problem running the engine while it's being flushed either. It seems like it would clean out the gunk better if it was warmed up.

So Jim, you used a bit of silicone sealant on the boots? I was wondering what if anything should be used there, thanks for the tip. Perkins doesn't mention any sealant on there.

Mark, I believe I will use the Valvoline G-05 product. I went and looked at it and it seems like a product I could use.

I'm still going to flush with distilled water only a few times before I refill the system, after that I'll attack the raw water side of things.

I appreciate the input from everyone. I was making it harder than I had to until The Happy Doctor Guy made the statement about it being the same as a cooling system on a vehicle......DUH, once I revised my search parameters, things became much clearer.......or they will soon anyway.

I think I'll go flush my FW system..... so after that, the heat exchanger ..... I like the wooden dowel idea.....seems much safer than a welding rod, I may try some hot vinegar also.

Again, thanks for all the input..............

John