Cleaning aftercooler and heat exchanger

[Nancy]

What's the recommended method of cleaning the aftercooler and heat exchanger (Cummins 6BTA 5.9)? I'm told that ultrasonic is the best technique. Who does this in New England?

[RobS]

Preventative or do you suspect a problem?

[ScubaPete]

Here's the scoop. The pics show the entire process.

http://boatdiesel.com/Articles/Articles ... ler&Y=2005

[RobS]

Yes, Tony's article on the aftercooler is perfect.

And as far as the heat exchanger, it can be done a few ways. It can be pulled and taken to a radiator shop. You can clean the tubes with a brass rod and then soak, flush, etc. Or you can do a whole seawater cooling loop rydlyme flush. That reminds me Kevin still has my custom made fittings for the rydlyme flush! If you want them I can have him UPS them to you direct. Search here on AOG for rydlyme, there is a post (with pics of course) from me and others.

Hopes this helps...

[Russell]

Nancy, you can take the end cap off the heat exchanger to see how much buildup you have. The cap at the front of the engine (boat stern) is the easiest to remove and you may see particles of old zincs that have broken off blocking some of the tubes. If your boat is like mine, the heat exchanger is dry of seawater at rest so removing the cap did not result in any spillage. I did the rydlyme flush a few years ago as a preventative even though there was little buildup in the exchangers. I did not notice any change in engine temperature but there was no problem to begin with. Be careful with the rydlyme.

[Nancy]

Thanks to all.

My notes from the previous owner don't say anything about having done aftercooler and heat exchanger cleaning. Cummins says this should be done every 500 hours....or every 3 years on a recreational engine. So it's probably time with the boat being new to us last year and coming from saltwater. The engine has 725 hours.

Russ, when you say to be careful of the Rydlyme, what are you referring to? (I haven't studied the web site yet.)

[marko]

I've got twin Cummins 6BTA's which were flushed with Rydlyme a year ago by a very good diesel mechanic. One engine had been over heating, the other ok. I had both done. The mechanic brought his own pump, buckets, hoses, etc as he'd done this many times. I believe the caution is due to the fact that the dilution and time of the flush is important. This worked out well for me, as there have not been any overheating issues since.

[kjg1951]

I hv been having overheating problems also . Have change th impller that did not make a difference. Having avolvo menchanic from Jarette Bay near New Bern N.C. come to look at it this morning. Will post his findings

[Russell]

Nancy Rydlyme is a very powerful acid so you must not get it on yourself or anywhere else but the heat exchanger. If one of the hoses comes off it could be a catastrophe.

[kjg1951]

Mechani c just left with heat exchanger and air cooler, could not find anything else that could be causing the over heating. will see whathappens when it is reinstalled and sea trial ... WOT produced 245-250 degrees......

[Nancy]

Thanks, Russ. Good to know especially since the web site touts "safe, biodegradable marine descaler". I guess it depends how you define safe.

[RobS]

... WOT produced 245-250 degrees......

That is HOT. The 6LP overheat alarm will sound at 210 deg F. I would change the engine coolant once you get the temp straightened out as you have approached the boiling point of a 50/50 mix...

[Pitou]

That reminds me Kevin still has my custom made fittings for the rydlyme flush! If you want them I can have him UPS them to you direct.

Packaged up and ready to ship. I thought I'd have a new boat by now to use them on before their return.

Here's a post to a picture of the Rydlyme flush on my 6BTA. Pretty simple set-up and if you pay attention there should be no problems.

viewtopic.php?f=7&t=5701&p=34136&hilit=Rydlyme#p34136

[Carl]

Just ordered the Rydlyme to do the flush as soon as I have a weekend off. Cruise temp was starting to stay around 180 and would creep higher at WOT. My only question is the 50/50 mix. If I flush system first with fresh water to check for leaks this will leave fresh water within the system. So do I simply add straight product to the bucket and start the pump? Or do I add some water, and if so how much? I purchased 2 gallons for the Yan 6LPSTP.

[marko]

A few comments with percentage of certainty noted: you know old guy, no notes as it's been a year since the mechanic did the flush for both my Cummins engines, and as I was the helper/gofer/ banker:
Temporarily remove all engine zincs. 100%
His hose and bucket rig bypassed the raw water impeller. 100%
He had his own electric pump with two 5 gal buckets. 100%
Afterward he replaced the heat exchanger end cap seals. 100% (both ends of the ea heat exchanger: umm?)
Flush with fresh water afterward. 90% (before re-starting engines)
The dilution was 50/50 +/- in the bucket. 80%, as his measurement not precise & I was cleaning as he went.
I believe he set it up to actually back flush, opposite of normal flow. 60% (crs)
Hopefully a little helpful.