Flushing the FW side

[HappyMdRSailor]

Originally Posted by Strait Shooter

The amount of gunk built up on the heat exchanger tube stack was pretty bad. Over a third of the holes are closed completely.

Now I can't get the tube to release from the heat exchanger body. I think it's because of hard crud build up at the meeting surfaces. Any ideas on getting this to release? I used a block of wood and a small trim hammer with no results. I'll try again today with a 5lb hammer.

I was thinking of removing the entire heat exchanger and bringing it into a radiator shop.w

Anybody?

I can see where some Permatex #2 would have prevented this build up at the mating surfaces.

YES!!!

They'll boil the whole lot, and return the pieces as purdy as new... well... new and pitted where the corrosion was anyway...

[a64pilot]

It will also be completely stripped of any paint, so go get some that will match.
Having a radiator shop boil one is the only way I know of to get one absolutely perfectly clean

[a64pilot]

If there is aluminum in the mix, make sure you point that out, I think the process may not be kind to aluminum?

[Strait Shooter]

Originally Posted by a64pilot

so go get some that will match.

Then I should return the pink and purple that Zee and Sailorchickee recommended?

I have the paint already. I'm going to replace some OEM hoses as well. I'm not sure about the aluminum, I'll check it out though and pay attention.

I had the opportunity a year ago to buy a spare heat exchanger tube. I didn't do it because I was bleeding money at the time on the refit. After doing this and seeing the interface between the two systems (FW/raw), I think a spare tube would be mission critical equipment for remote exploring. That's just me though.......

I will keep everybody posted, again, many thanks .......


John

[a64pilot]

I haven't had to buy one, but think they may be terribly expensive at least for a Yanmmar, don't know about Perkins

[Strait Shooter]

I saw one a year and a half ago for $400. I shoulda grabbed it.

I got the heat exchanger off today, it's all aluminum. The crud that was in it was incredible. Lots of build up of hard deposits as well as slimy clear jelly bean shaped gunk........I'll drop it off tomorrow at the radiator shop.

The engine needs a thorough cleaning now........and some new hoses.......and paint........and and

[Yeti]

For a reference point...

Ace Radiator in San Diego charged me $165 to boil, repair or resolder any little things, place a new zinc, and repaint. This was for a Universal M25XPB HX. Same charge as well as a slightly larger HX that was used on my old Volvo Md2B.

[UNCIVILIZED]

Man, this thread is like one product commercial after another!

[delmarrey]

Originally Posted by 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.
John

I haven't read all three pages of the thread. But the substance, did it seem a bit oily. You may want to have it checked for traces of motor/diesel oil. That would be the first signs of a head gasket leaking. Usually, old antifreeze leaves crystals behind not a sludge.

[delmarrey]

Originally Posted by Strait Shooter

I saw one a year and a half ago for $400. I shoulda grabbed it.

I got the heat exchanger off today, it's all aluminum. The crud that was in it was incredible. Lots of build up of hard deposits as well as slimy clear jelly bean shaped gunk........I'll drop it off tomorrow at the radiator shop.

The engine needs a thorough cleaning now........and some new hoses.......and paint........and and

Sounds like what was under my mast step when I pulled it last year.

[Strait Shooter]

Originally Posted by UNCIVILIZED

Man, this thread is like one product commercial after another!

Really? I'll have to go back and reread it. I remember one or two, I guess I should pay more attention.

[Strait Shooter]

Originally Posted by delmarrey

I haven't read all three pages of the thread. But the substance, did it seem a bit oily. You may want to have it checked for traces of motor/diesel oil. That would be the first signs of a head gasket leaking. Usually, old antifreeze leaves crystals behind not a sludge.

No, it didn't seem oily. It had/has crystalline build up at almost all of the fittings. The translucent globules when pinched were sometimes soft and sometimes hard, as if the soft crap was in the process of hardening. I had small chunks falling out when I turned it upside down. I'm pretty bummed I didn't heed the warning of the temperature rise sooner.

Is this normal for an engine with low hours? (250).

I think at some point, maybe something got mixed in there with something else and the two something's didn't necessarily like each other. I'm just guessing though. The more experienced folks are suggesting that a mixture between raw water and FW systems could cause a build up like that. This is new territory for me, so again, I have no clue what happened, I'm just trying to recover from it the best way I can, and prevent anything like it from happening again, or at least as often.

The engine was smoking (grayish blue) more and more, it's not a lot, but I noticed it. Could that have been because of it running hotter than it should? I also noticed that the exhaust ports had a carbon build up that seemed excessive and black. Anyone?

The mating surfaces seem fine and do not appear to be warped or anything. I only checked with a straight edge though and will look more closely at them during the clean up process. I saw no evidence of any kind of fluid or gas exhausting past any gaskets, I'll take a closer look at that also.

It has an exhaust gasket in between the heat exchanger and the engine block. It looks like it's in good shape, do I absolutely have to replace it automatically? The shop manual says that no joint compound is needed, at first I was wondering why one would compound matters by smoking a joint, then I realized it meant gasket sealer. So it IS like an exhaust gasket in that regard?

I appreciate everyone's patience with me, I've not been around diesels much, or boats for that matter. I realized while hanging upside down in the engine room last night that I freaking love this stuff though Just wish I'd have started earlier..........

[Maine Sail]

Originally Posted by 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

Depends what engine but once the HX is removed I pull the t-stat and replace the t-stat housing. I then flush the engine with Rydlyme using an inexpensive 12V pump and an in/out bucket.

The valve on the clear return hose in the bucket is to throttle the return in order to keep system pressure just below the radiator cap blow point and to ensure all internals are cleaned with Rydlyme...

I let this run for over an hour. Periodically opening the valve all the way to let any crud blast away.

Keep the supply hose off the bottom of the bucket some. Once the system is flushed with Rydlyme I flush it with clear water. It takes a lot. Probably 20+ gallons before it really runs clear. I then run 5 gallons of distilled through it and put her back together.

Once back together straight AF is added until the mix in the engine meets desired AF performance results. I leave the stat out until everything is bled and the AF mix is correct.

On my own boat I installed a coolant header tank in the water heater loop. This makes a great high point in the system and makes AF changes yearly very, very easy.. I added a 1/4 turn drain cock at the low point on the HX.. Drain a bit out at the low point add some at the high point and it self bleeds. Takes me all of about 20 minutes to flush the AF in the engine... Stanley at Beta Marine has a great header thank for a reasonable price..

P.S. Westerbeke shipped my engine with Death Cool (AKA Dex Cool) in it. You do not want to mix AF types, and I will not personally use Dex Cool, so a full flush was required.

[jimbunyard]

Did a little reading on this particular system.

Given the described level of corrosion, I agree it's a good idea to send it out. Be careful though, use a reputable shop, and remind them that the housing is aluminum. Caustic solutions used to dissolve mineral deposits will also completely dissolve aluminum castings. Seen it happen...

And, given the level of corrosion, the oil cooler needs also to be looked at.
If you have the engine exactly as depicted in the 2 previous pictures, the oil cooler coolant comes from the freshwater side and the cooler would not normally be suspect, but, again, with the corrosion described it should be checked visually and cleaned by the rad shop if questionable. You'd only be able to get about half the tubes with a rod in this sealed-type exchanger; any mineral deposits have to be boiled out.

If you have any other permutation of the engine, the oil cooler may be cooled by seawater, but we'll wait on that.

At 250 hrs, the level of corrosion described could only be considered normal if something was wrong; seawater/freshwater mixing, mixing of incompatible coolants and/or additives, or remotely, some kind of electrolytic problem. I'm leaning to either seawater/freshwater mixing or the use of propylene glycol antifreeze.

Certainly the smoke could be caused by overheating, but one problem at a time. You know this needs to be addressed, and while it's not exactly simple, it's simpler than pulling an overhead cam head. The engine only has 250 hours, just keep your fingers crossed.

Maybe we could de-compound matters by jointing a smoke, then we could put off engine problems till tomorrow.

But yes the gasket is just a combination intake and exhaust gasket, from the pictures I saw in the Volvo service manual no coolant is transferred through that interface, so technically you could reuse the gasket (been there) but that seems a false economy. If you do reuse it, that might be a good place for #2.

Regarding the tube bundle being stuck, besides the corrosion, there may or may not be a seal near each end of the bundle. It appears to me that these have a couple of functions, but they need to be in the correct place in the exchanger tank to perform them. It also looks like that if they're in the proper place, in conjunction with the corrosion, they would tend to lock the bundle in. You should know more when you get it back from the radiator shop. From the service manual it looks like these seals may be optional.

Given the level of corrosion, it seems mandatory to flush the system really really well. Whatever flush system you work out, start with just a tap water fill, run 5 minutes, drain, then system cleaner flush (as per manufacturers instructions, maybe longer on the run time) followed by another couple clean water flushes, then fill with distilled water and antifreeze (distilled water because most tap water is full of various dissolved minerals). Removal of the t'stat is necessary. I like to use as little A/F as possible, the best coolant (from a heat transfer perspective) is pure water with a corrosion inhibitor/lubricant. Of course I live in the south, it rarely freezes here.

I agree there's some kind of weird enjoyment fooling with this stuff. Not exactly fun, but I guess satisfying or something...

[Strait Shooter]

I just finished the removal, cleaning, and replacement of the heat exchanger on my Perkins M-50.

The space in between the tubes in the heat exchanger was a solid mass of hardened gunk.

I believe two issues have been at play in my engine. There was a leak between the fresh water side and the raw water side at the rubber boot interface. There was no sealant used between the rubber boot and the tube stack originally. I have some pics on another device that I'll post later, and it becomes obvious that there was some blow by happening which resulted in a mixing of fresh water and raw water.

The second issue falls at my feet as an inexperienced diesel engine operator. When I put my boat on the hard last winter, the yard boss told me to put some anti freeze in both the raw, and the fresh water cooling systems. He advised that the "pink" R.V. type antifreeze was the only sensible thing to do. He never mentioned that you should flush your system first to avoid mixing two anti freezes that don't belong in the same room together, much less my engine. I'll take the hit on that one...maybe I could have known better.

Repeated flushing of the heat exchanger when it was off the engine was amazing. The amount of crap I got out of the aluminum body is amazing.

Today when I reassembled everything, I filled it with the proper mix of antifreeze and ran the engine. The engine is still running in the 195-200 F
range, and I was expecting it to be running a little cooler than that.

I don't think I did anything wrong, but I guess it's possible.

The exhaust smoke is greatly diminished BTW.....