Generator Block Heater

[Sadey]

I love how my DD's respond to the block heaters. My 8KW has glow plugs and starts right up. My 20KW doesn't them and takes a little cranking to start in the cold water temps we live in. Has anybody installed either block heaters or pan heaters on their gensets?

 

[jim rosenthal]

I have had great luck with Wolverine oil pan heaters. They are sold under a different name, now, I think. Easy to install and very reliable.

 

[Captain Ralph]

My 8KW has glow plugs and starts right up. My 20KW doesn't them and takes a little cranking to start in the cold water temps we live in. Has anybody installed either block heaters or pan heaters on their gensets?

What 20kw do you have?
The MD4 (OhNo 20) has glow plugs.

For a laugh; There was a coolant water heater for the MD4 & 6s.
OhNo part number 333-0255-01.

 

[Sadey]

Okay Ralph you put me in the books. Details: my little genny has glow plugs which the start/stop was never wired correctly from day one to preheat. Only way I discovered it was the 8KW (MDKD) started fine in Florida even without using the plug procedure. PO’s captain went through a few days of instruction and never started the genny that way so I did it the same way. Shame on me for not following up in the book. Once we got to Wisconsin the 8 wasn’t staring like before. So our mechanic discovered the glow plug problem, installed and wired the switch and now she starts right up using the plugs. After that I went into the ops book for my 20KW (MDL4) and found no mention of plugs or procedures related just a note about “preheat if required” those three words only, nothing else.
So, after Ralph’s comment about his plugs I went back into both the ops and parts book for the 20. In the parts book there is a part number for glow plugs. Oh, I have them!? Now, what is the procedure to preheat. Is it the same for the 20 as the 8? They are both ONANS.
Questions:
How to test if plugs are working
If they’re working, anything else I should trouble shoot for hard starting?
Always starts just takes a while, especially when it’s cold.

 

[Captain Ralph]

Now, what is the procedure to preheat. Is it the same for the 20 as the 8? They are both ONANS.
Questions:
How to test if plugs are working
If they’re working, anything else I should trouble shoot for hard starting?
Always starts just takes a while, especially when it’s cold.

Without digging in my notes, should be the same a your 8. Hold the bypass switch down for a 10 count and start.
You can check B+ at the glow plugs with a volt meter.
With an IR heat gun, check if they warm up when holding down the bypass switch.
I recall a large wire wound resistor between the engine head and generator end. Think it was a load resistor before the glow plugs. Never witnessed it but always figured it could fail one day.

Other starting issues include air in the system. That darn square fuel filter thingie and ole mechanical fuel pump may let some air in as gravity tries to pull fuel back to the tank.

 

[Sadey]

Thank you Ralph. I figured that was the procedure but wanted to ask. I’ll give that a shot. I’ll check that filter. Sky hooked me up with a host generator to get a replacement housing for the filter which I needed. Maybe it’s not on correctly. Both generators run well it’s just the 20 takes a little cranking to fire up. I alternate between gens each trip to keep them both active. Most days it’s hard to load the 20 up, not a lot of days need the ac units going up nort, ya know.

 

[Captain Ralph]

Most days it’s hard to load the 20 up,

Drag you feet messing with the fuel filter then. put it on the bottom of the list (way down).
If it pulls the load and ask for more, you may just have a cold starting issue; Glow plugs.

I used to install NL 12 and 20 sets on Hatter-ass's, Glow plugs are required in north Florida year round when starting cold.

 

[ageless]

From my manual

 

[Captain Ralph]

Yep, 10 seconds = 10 count (approx). That would be the norm in N FL.
In Wisconsin? Well, Got me...

 

[Sadey]

That looks exactly like the page from my 8KW. This is the page from my 20KW.

 

[Captain Ralph]

Not enough resolution to read, but may read the same as before pic.

 

[Sadey]

I know I just tried to upload another picture and it didn’t work either, so I deleted it

 

[Sadey]

Maybe this is better

 

[Captain Ralph]

Maybe this is better

Do you have 2 switches or one start/stop switch. Sadly, your page is confusing.

Confusing to me as I am used to two switch starting on gen-sets.

 

[Sadey]

Both generators only have one switch at each location. One switch each at the AC distribution panel at the helm and one switch on each unit itself. The start/stop/off switches at the AC distribution panels are a momentary start/stop with a spring loaded to center off position. There’s no placard or anything indicating preheat. Just simply start/stop/off placard. The mechanic working on the switch for the 8KW discovered it was the wrong switch. It was a momentary start spring loaded center run with a latched stop position. During the start sequence, the glow plugs were not energized. That’s when he realized it was the wrong switch to begin with. Which appeared to be original from the factory. He ordered the correct switch and wired it and now I’m able to follow the procedure to preheat the 8KW. The 20KW has the same switch as the 8KW but there is no reference to any sort of glow plug procedure in the manual or any placard anywhere. Just simply a part number for a glow plug in the parts manual.

 

[ageless]

My panel

 

[Captain Ralph]

Press and hold the stop for 10 then start???

 

[Avenger]

How about that button that says "Preheat?" Something like that on your panel?

The manual appears to call out an auto-crank system. In which case any preheat should be built into the automatic start sequence.

How about some pics of the generator itself. Particularly of the cylinder head where the injectors are and the intake manifold? We should be able to visually determine if you have glowplugs or an intake heater.

 

[whoover]

My MDJE 6.5 had a separate preheat switch, on the remote panel and on the set itself. The instructions were to hold the preheat for a full minute.

Walt Hoover

 

[madhatter1]

I’ve been starting mine wrong since I bought the boat. But my 13KW starts right up. Florida.