Official Cummins 6cta 450C thread

I do hear it, but it sounds like an external rattle. ck to be sure your remote oil filter is tight, then all the other stuff that is bolted to the outside of the engine.
 
Jaybeaux, Don’t need a special tool for tdc.
Valve clearances are 12 and 24 thousandths. So for a .012, the .012 fits with some resistance. .013 wont go.
Complete instructions are in the owners manual. Should not need new gaskets.
As others have said, it’s really easy but if you’ve never done it, there’s always concern. I show others how to do it and the response is always “really, it’s that easy?”
 
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A few tips for the shady tree mechanics with valve timing.

There is a onboard pin on the front of the engine to locate TDC. It is plastic, and not designed to HOLD, so do not force the engine when inserted.

You will not be able to "bar over" the engine on the crankshaft, but can using the alternator pulley.

The specs for valve clearance is printed on the engine tag, specific for your engine.
 
Maybe because I don’t have a decent speaker available to me right now but on my cell phone I don’t really hear anything. You said you took a good look around, how about up front in thebelt tensioner area?
Does it still do it when you drop it into gear? If it sounds like a general central ticking it could be valves. Take the oil fill cap off and listen. Louder?
Were valves ever adjusted? How many hours on engines?
Don’t fear valve adjustment, piece of cake. You’ll get it sorted out. Good luck
More obvious when I listen with stero headphones . You can definitely hear a pronounced rattle.
 
Steve

it does sound like valves to me. I would change the tensioner as well
 
Yeah, well it bothers me enough that I called a tech in for this one. One that knows my engines well. I’ll let you know what we learn on Friday.
 
Ok. I hope I am done. I bought the boat in late 2013. That's at the end if it's 13th season. I didn't know enough to know at the time, but just about all the bolt ons to the engines were at or near end of life. Since purchase I have:

Replaced seawater pumps
Pressure tested heat exchangers
Replaced aftercoolers
Replaced gear oil coolers
Rebuilt both turbos
Replaced wet exhaust mixers
Replaced exhaust hoses/elbows
Replaced all seawater hoses
Replaced all clamps
Replaced aft seawater pipes
Removed air grid heater circuitry
Removed fuel coolers
Replaced port alternator
Adjusted valve lash
Tuned props to 22.7 pitch
 
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Ok. I hope I am done. I bought the boat in late 2013. That's at the end if it's 13th season. I didn't know enough to know at the time, but just about all the bolt ons to the engines were at or near end of life. Since purchase I have:

Replaced seawater pumps
Pressure tested heat exchangers
Replaced aftercoolers
Replaced gear oil coolers
Rebuilt both turbos
Replaced wet exhaust mixers
Replaced all seawater hoses
Replaced all clamps
Replaced aft seawater pipes
Removed air grid heater circuitry
Removed fuel coolers
Replaced port alternator
Adjusted valve lash
Tuned props to 22.7 pitch
How many hours did the major items have on them?... I know salt water will speed things up, was just curious
 
How many hours did the major items have on them?... I know salt water will speed things up, was just curious
The boat had about 1050 hours on it when I bought it. It now has 1900 hours. It has been a southeast salt boat it's entire life.
 
Yeah, well it bothers me enough that I called a tech in for this one. One that knows my engines well. I’ll let you know what we learn on Friday.

As it turns out, this was a total non-issue. The engine is running great. The rattling I heard was not the valves at all but a loose lower bolt on the oil filter bracket. It was intermittent and didn’t rattle all the time and sometimes disappeared with increased RPM. And it wasn’t so loose that you’d feel it if you touched the filter. But that’s what it was. I feel I could have found this, so I’m a little humbled by this. And annoyed – I think I would have found this in another month when I changed my oil! Oh well, I got to chat with the tech about my tachs (he verified they were spot on – which means I need a slight re-propping) and we discussed changing the oil pressure sender on the port engine (ugh) and winterization. But no problems with the valves or the innards of the engine. Whew!

And thanks for all the tips. I'm going to look back into the service records and see when the valves and tensioners were last worked on...
 
As it turns out, this was a total non-issue. The engine is running great. The rattling I heard was not the valves at all but a loose lower bolt on the oil filter bracket. It was intermittent and didn’t rattle all the time and sometimes disappeared with increased RPM. And it wasn’t so loose that you’d feel it if you touched the filter. But that’s what it was. I feel I could have found this, so I’m a little humbled by this. And annoyed – I think I would have found this in another month when I changed my oil! Oh well, I got to chat with the tech about my tachs (he verified they were spot on – which means I need a slight re-propping) and we discussed changing the oil pressure sender on the port engine (ugh) and winterization. But no problems with the valves or the innards of the engine. Whew!

And thanks for all the tips. I'm going to look back into the service records and see when the valves and tensioners were last worked on...
Great news. I have worked on that sender. Easy to get to from above. I had no problem. Of course I don't have all the air heater crap in the way anymore. My bouncing gauge turned out to be a failed ring connector on the wire end at the sender. Not the sender itself.

also, several of us have found that once the valves are adjusted the first time, they stay pretty stable from then on. If you find they have been done, you may be in good shape.
 
Phew....faith restored in the 450C! Let me know how the oil pressure sender replacement goes. I replaced mine but now the gauge spikes. I have to try to ground it somewhere else to see if that fixes it. But glad it was a non issue.
 
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Great news. I have worked on that sender. Easy to get to from above. I had no problem. Of course I don't have all the air heater crap in the way anymore. My bouncing gauge turned out to be a failed ring connector on the wire end at the sender. Not the sender itself.

also, several of us have found that once the valves are adjusted the first time, they stay pretty stable from then on. If you find they have been done, you may be in good shape.

The sender diagnosis is going to be delayed. From looking at the SB engine, I know I can get to the sender, check the wire or even replace it, from above. Unfortunately, to do so I need to talk out the sofa so that I can fully open the port hatch. That's not happening until I'm done using the boat for the season. And it might wait until spring, when I have to remove the sofa to open up to get someone to change the impeller on that side and do the AC and HE cleans.
 
The topic is serpentine belts. I just completed 2 years on my belts, a bit over 150 running hours. It helps me sleep knowing that it is time to change them. I keep old ones as emergency spares.

I just received an email from Diesel Parts Direct, from whom I have purchased parts. They are offering free shipping as their latest marketing gimmic. Shipping charges last time was $16+.

A search on my belt, part # 3288812, shows 2 options: Genuine Cummins @ $67.59 each; and and after market for $50.58. See link: https://www.dieselpartsdirect.com/search?q=3288812

This is the first time I remember seeing the after-market flavor on this site. Would you use it? Or am I being penny wise and pound foolish? Thoughts?

Jaybeaux
 
A lot of times the same manufacturer makes both... but more often it's cheaper because it is cheap. If you cant figure out who made the aftermarket belt I would stick with Cummins
 
That is beautiful work. You could not pay someone to do that quality work!
 
Sorry for the confusion. I am attempting to get the pictures to upload correctly.

Anyway, we painted the engines, rebuilt the turbos, replaced all hoses, powercoated the aftercoolers, elbows, and piping. Also replaced wire loom and zipties. Just generally freshened everything up.

I still have the Genset to do as well as paint the turbos with Ceremic high heat paint and replace the fuel coolers which I also had powercoated.

For reference I used Rust-Oleum Canvas White paint with some Majic hardener added. I handpainted everthing after wire brushing and treating with Ospho.

There are 6 engine room lights which are Lumitec Ibiza and there is such thing as "wire loom tape" which is absolutely amazing and available on Amazon.

The after bilge under the Genset is painted with Interlux Bilge Kote Gray and I plan to expand this once I finish he other detail work back there.

Lastly, I have a local friend who made the decals on the engines so they all look nice and new as well for a final touch.


If you see anything out of the ordinary feel free to let me know.

478CD3C4-A384-4BF3-A4BA-9044564622D0.jpeg
D3E1AFA6-A9A7-4BDE-ABFF-2DCD9FBD48FF.jpeg
940E2498-8B03-4AAD-A3AF-0E6A569A4F07.jpeg
422771C3-8D19-4235-BBA5-B63E2BA3F071.jpeg
E5F20589-348A-4AE0-86E0-AD2CD11DF61C.jpeg
1AB4E876-040D-474C-9B25-B0E17B740447.jpeg
B8A50514-8774-40C7-8D73-4E67903E42D5.jpeg
3F7DAA29-C207-42BB-A766-6966A78F6711.jpeg
87A097DB-9098-4AD7-B2F4-E475D05D55E6.jpeg
 
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Sorry for the confusion. I am attempting to get the pictures to upload correctly.

Anyway, we painted the engines, rebuilt the turbos, replaced all hoses, powercoated the aftercoolers, elbows, and piping. Also replaced wire loom and zipties. Just generally freshened everything up.

I still have the Genset to do as well as paint the turbos with Ceremic high heat paint and replace the fuel coolers which I also had powercoated.

For reference I used Rust-Oleum Canvas White paint with some Majic hardener added. I handpainted everthing after wire brushing and treating with Ospho.

The engine room lights are Lumitec Ibiza and there is such thing as "wire loom tape" which is absolutely amazing and available on Amazon.

The after bilge under the Genset is painted with Interlux Bilge Kote Gray and I plan to expand this once I finish he other detail work back there.


If you see anything out of the ordinary feel free to let me know.

View attachment 76604View attachment 76605View attachment 76606View attachment 76607View attachment 76608View attachment 76609View attachment 76610View attachment 76611View attachment 76612


That is boat porn at its best!

Looks really good.
 
No that's the "Shown" hours not the "true" since I replaced the Tachs. I keep the actual Hours in my logs. I'm not making you look bad, just giving you inspiration!
 

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