Official Cummins 6cta 450C thread

[Woody]

My port engine started running hotter end of last season. Normally a needle over 160 it started running near 185. A couple things I noticed was that by the time the gauges got to 130 the fluid level in the plastic expansion bottle was already starting to rise and the heat exchanger was getting quite a bit warmer when it normally is cool to the touch.

The heat exchanger, aftercooler, and impellers were all serviced at the beginning of the season. I had even changed the original radiator caps just because. Temps were fine until end of season.

Last weekend I was looking at the big hose from thermostat hosing to heat exchanger. It always had a bit of different shape, kind of flattened out. I was wondering if something simple like a deteriorating hose might be my problem. While pondering this I was squeezing the hose comparing it to the other engine. Along with whooshing of fluid I heard a faint muffled sound like metal bumping on metal. I had thermostats and some new hoses so I took it apart.

What I found was one thermostat had fallen apart. I lifted the one out of the bypass side first it was complete. When I looked in the hole I could see a bit of brass balanced in the hole through the partition between thermostats. Not realizing what it was I stuck a finger in there and knocked it off, kerrrrplop. The one side is deeper and had some antifreeze in it, if the part would have been already in there I might not have thought to probe around. I fished it out with a magnet.

I changed the thermostats, put on a new hose(but the old one was OK) and the engine is running a needle over 160 again. Here's some pics to help figure out what I'm talking about.

 

[Jaybeaux]

Update: Today, I changed the Starboard Waterpump Impeller. No torn "blades", but it did have a set to them, and there were some cracks beginning to develop. Time to change it. 147 hours and 2 years of service.

Went out for a test ride, and I still get the a bit higher than usual temperature.

At this point I was leaning toward a heat exchanger cleaning with Rydlyme or the like. But after reading Woody's post (#141), I'm beginning to have a change of heart. My symptoms are exactly what Woody described, though I haven't laid hands on the hose, nor heard the metal on metal sound.

As a next course of action, would you guys recommend T-stats or Heat-exchanger? As mentioned previously, I was planning to do the aftercoolers and heat-exchangers this fall/winter.

Thanks in advance.

Jaybeaux

 

[Jaybeaux]

Woody, I see a jug of coolant on the deck. I assume you had to drain all or some of the coolant from the system prior to removing the thermostat housing and the the T-Stats themselves. Can you describe how you did that for the uninitiated?

Thanks. Your post is very timely and helpful.

Jaybeaux

 

[Woody]

Woody, I see a jug of coolant on the deck. I assume you had to drain all or some of the coolant from the system prior to removing the thermostat housing and the the T-Stats themselves. Can you describe how you did that for the uninitiated?

Thanks. Your post is very timely and helpful.

Jaybeaux

One of the hoses going to the coolant filter was long enough when unhooked that it could reach that plastic container when I had it sitting up on a small pail between the engines. I had a real small pair of vise grips with flat jaws that I used for a hose pinch off tool. I shut off the valves at the coolant filter, pinched off the hose so it wouldn't make a mess, then disconnected the end at the filter. I don't know if you could completely empty all antifreeze from there but I let out close to 6 gallons when I stopped.

What I found has to be a real fluke. I tried simulating position in the one pic but the thermostats are actually much closer together than that as you can see in the pic of the new ones installed. The flow coming up from the bottom had enough force to lift that part, buffeting it around until the small end finally went in between the thermostats and into the hole in the partition. I think it restricted enough of the flow to cause the increase temp.

I'm not sure what to think in your case. Do you get into saltwater? If so and it's been awhile since last service I think I'd lean toward the coolers. In any case changing thermostats is not a difficult job. I did skin up my shins a little but they seem to catch hell no matter what I do.

 

[Jaybeaux]

Woody,

re: saltwater. The upper reaches of the Potomac are either fresh or brackish at any given point in time. I've been down towards the Chesapeake Bay a few times, but not actually in it. The closer you get to the bay, the saltier the water gets. A buddy of mine, retired Navy and Civilian DoD, says that freshwater kills saltwater stuff, and saltwater kills freshwater stuff.

When I finished installing the impeller, I spent a few minutes wiping up the blood and sweat that I had left behind. My right cheekbone is very sore from getting up close and personal with the starboard exhaust tube.

Jaybeaux

 

[FeLizDream]

I took Aftercoolers and Heat exchangers for services, had to buy new cores for the After coolers, everything is clean inside and painted outside ready to be mounted.

 

[FeLizDream]

Also changed the exhaust hoses (they were dry and leaking salt water after running) for the blue silicon ones. Very easy to install.

 

[FeLizDream]

Went out for a short trip to test the boat with the new coolers, they ran at 160 F, very smooth, but the Port engine only went to 1,300 rpm, Starboard was fine doing wot 2650. After a lot of checking in the engine room i found out a small oil leak on the bilge, looked for the oil all the way and it was coming from the After-cooler little hole ( condensation drain hole that i have in my after-coolers), call the Broward radiator shop, and he told me the only way to get oil in the after-cooler is from the turbo, check the turbo. Went back to the boat removed the turbo took it to RPM Diesel to check the port turbo, and the turbo was bad, the axle inside was torn, impossible to rebuilt, so just bought a new turbo from them ( at a 35% better price than Cummins, and original manufacturer) , I just notice all the time is better to buy from a distributor than directly from Cummins, I always got a 15% to 35% discount on price buying from an authorized distributor, so new turbo is going underway to be installed this Friday. See carefully the oil leaking from the Port after-cooler and the OEM new Turbo.
Notice in the Picture the drain hole in the after-coolers, the drain is prevent for condensation water in the inside, it is so small that I dont notice any lost of power or turbo boost.

 

[NotHerDecision]

I think you just changed the hoses so you could out do the rest of us with those fancy blue silicone hoses! Looks great!

The turbo is rebuildable. There is a shop in Florida. I’m sure Bill will chime in soon with the info!

If you’re not going to rebuild it I would be interested in buying it.

 

[ZZ13]

I think you just changed the hoses so you could out do the rest of us with those fancy blue silicone hoses! Looks great!

The turbo is rebuildable. There is a shop in Florida. I’m sure Bill will chime in soon with the info!

If you’re not going to rebuild it I would be interested in buying it.

Yup. DMS in North Palm Beach Gardens, Fl. He rebuilt my starboard turbo in one day. As good as new for about 2/3 the price. Uses all new parts and only reused part is the housing. And he machines in a perfectly specified sleeve for the exhaust side of the housing (where rust builds up over time in salt environment). Contact info is 561-644-6537. Great to chat with about any turbo problem. Knows his stuff.

Here is the before and after of mine.

 

[FeLizDream]

Looking why my turbo fail, took the exhaust mixer for clean up and find out it was leaking, time to buy 2 new exhaust mixers, called Cummins for price and it is like $2,300 each. Called D’Angelo in Fort Lauderdale, they don’t have it in stock but they can build 2 new ones for me in about 10 days . They have 2 prices one for 3 years warranty and another with 5 years warranty made out of INCO ALOIL or something similar, I will go with the best one, at 60% off the price than Cummins.
I took the exhaust mixer to a dark room put a flash light inside, and it was like 20 little holes leaking.

 

[NotHerDecision]

Wow... That looks to be in great shape from the outside. What would you speculate to cause this? Zincs?

Josh

 

[FeLizDream]

Yup. DMS in North Palm Beach Gardens, Fl. He rebuilt my starboard turbo in one day. As good as new for about 2/3 the price. Uses all new parts and only reused part is the housing. And he machines in a perfectly specified sleeve for the exhaust side of the housing (where rust builds up over time in salt environment). Contact info is 561-644-6537. Great to chat with about any turbo problem. Knows his stuff.

Here is the before and after of mine.

Nice job, thank you for the information, they told me it was too bad to rebuild mine, better go with a new one, they gave me an excellent price, I left my old turbo in the shop, so they could use it.
The problem was the exhaust mixers are bad, leaking salt water, looking to buy 2 new ones.

 

[FeLizDream]

View attachment 57625 My port engine started running hotter end of last season. Normally a needle over 160 it started running near 185. A couple things I noticed was that by the time the gauges got to 130 the fluid level in the plastic expansion bottle was already starting to rise and the heat exchanger was getting quite a bit warmer when it normally is cool to the touch.

The heat exchanger, aftercooler, and impellers were all serviced at the beginning of the season. I had even changed the original radiator caps just because. Temps were fine until end of season.

Last weekend I was looking at the big hose from thermostat hosing to heat exchanger. It always had a bit of different shape, kind of flattened out. I was wondering if something simple like a deteriorating hose might be my problem. While pondering this I was squeezing the hose comparing it to the other engine. Along with whooshing of fluid I heard a faint muffled sound like metal bumping on metal. I had thermostats and some new hoses so I took it apart.

What I found was one thermostat had fallen apart. I lifted the one out of the bypass side first it was complete. When I looked in the hole I could see a bit of brass balanced in the hole through the partition between thermostats. Not realizing what it was I stuck a finger in there and knocked it off, kerrrrplop. The one side is deeper and had some antifreeze in it, if the part would have been already in there I might not have thought to probe around. I fished it out with a magnet.

I changed the thermostats, put on a new hose(but the old one was OK) and the engine is running a needle over 160 again. Here's some pics to help figure out what I'm talking about.
View attachment 57613 View attachment 57614 View attachment 57615 View attachment 57624

Woody, what a great post, thank you for sharing it

 

[FeLizDream]

Wow... That looks to be in great shape from the outside. What would you speculate to cause this? Zincs?

Josh

No idea, maybe zincs, from outside looks perfect from inside all pitted
Just for precaution I will fabricate 2 new ones with D’Angelo.

 

[ZZ13]

No idea, maybe zincs, from outside looks perfect from inside all pitted
Just for precaution I will fabricate 2 new ones with D’Angelo.

Josh, what are your thoughts regarding your zinc theory? I figured salt water just eats away at them over time. We all may be on borrowed time if we are still running the original mixers. I'll check mine again when I do the aftercoolers this fall. It's only a $12 gasket to pull them off and check them (if your bolt heads are still good).

Amazing that a mixing elbow costs more than a turbo.

 

[douglee25]

View attachment 57804 View attachment 57802

Looking why my turbo fail, took the exhaust mixer for clean up and find out it was leaking, time to buy 2 new exhaust mixers, called Cummins for price and it is like $2,300 each. Called D’Angelo in Fort Lauderdale, they don’t have it in stock but they can build 2 new ones for me in about 10 days . They have 2 prices one for 3 years warranty and another with 5 years warranty made out of INCO ALOIL or something similar, I will go with the best one, at 60% off the price than Cummins.
I took the exhaust mixer to a dark room put a flash light inside, and it was like 20 little holes leaking.

The material is Inconel. Nickel based alloy that is very corrosion resistant.

 

[FeLizDream]

The material is Inconel. Nickel based alloy that is very corrosion resistant.

check out the bonding in the wet exhaust, DeAngelo told me even it is very important that the wet mixer exhaust must be bonded, even though it is connected to the engine it must be bonded. see picture attached showing the bond connection, mine wasn't, i don't know it ever was connected or the P.O. disconnected it, i will connect the new one using the bond green cable in the DeAngelo elbow.
Check if your is bonded ? and let us know. I will do both because if one was bad the other one must be almost gone.

 

[ZZ13]

View attachment 57987
check out the bonding in the wet exhaust, DeAngelo told me even it is very important that the wet mixer exhaust must be bonded, even though it is connected to the engine it must be bonded. see picture attached showing the bond connection, mine wasn't, i don't know it ever was connected or the P.O. disconnected it, i will connect the new one using the bond green cable in the DeAngelo elbow.
Check if your is bonded ? and let us know. I will do both because if one was bad the other one must be almost gone.

I have been on a lot of boats with the 6CTA and that mixing elbow, including about six 400DBs, and not one has that mixing elbow bonded with a wire at that tab.

 

[J.Wilt]

My Starbard engine starts slower than the port.
Do you have a part # for the switch?