Just bought an M923 and I have several questions

[TacticalDoc]

My M923A1 does the same thing. A2 is quieter but I wanted a bigger motor just in case I want to add a turbo on it later for more power.

 

[joesco]

Can you or someone tell me how that works ? Just curious.

Today's diesel fuel has a lot less lubrication, adding 2 cycle oil lubricates the injection pump and the truck just seems to run quieter.

 

[randygk]

Funny thing about those 250s... when running properly under load down the highway, the engine sounds like someone is rapidly hammering on a coconut.

What size coconut? Yes, this noise has always concerned me. Had several deuces, GM diesels, worked on boats with diesels, just got a Cummins 6.7 - but the 250 has been different and thought maybe some things were going to let go holding hands any minute.

 

[DJones]

Today's diesel fuel has a lot less lubrication, adding 2 cycle oil lubricates the injection pump and the truck just seems to run quieter.

I do the same thing.

 

[DocPA]

85 M923 A1 NHC 250 water filter

Anybody installed a water/chemical treatment filter on a NHC 250 cummins. If so at what point do you tap into the cooling system??

Anybody else have a noisy 250 at idle? like a fuel knock that clears right up raising the rpm. no miss,runs great.

How about a locking fuel cap for the 85 general 923 ?

I'm planning on relocating this truck from Arizona to the East coast. Has anyone changed the rear wheel bearings over from grease packed to just gear oil ? Any advantage to that ?

Finally anybody got a reliable answer on the MPG of a 923 nhc250 with super singles with maybe a 5,000 lb payload?

Thanks in advance, Doc

 

[98G]

6 mpg cruising at hwy speed.

Locking fuel cap available from those military guys in so cal, or I'll be happy to fab one for you.

 

[juanprado]

check my build for the water filter install I did
major zippidy

 

[162tcat]

#1 Parallel to the heater lines is easy or add 2 more valves. Outlet in the water manifold and mid block return.

#2 Adjust the injectors and valves. Search or see stickie at top.

#3 Locking fuel cap is available at any truck place or ebay for around $20. Those military guys just paint it green and double the price.

#4 Been done, search.

#5 6mpg is pretty accurate.

 

[allpredatorcalls]

#3 Locking fuel cap is available at and truck place or ebay for around $20. Those military guys just paint it green and double the price.

Thanks for the heads up on the alternate locking fuel cap source, just saved me $40

 

[162tcat]

Thanks for the heads up on the alternate locking fuel cap source, just saved me $40

No prob. Everyone is on a budget these days, money saved is a good thing. Especially if the wife is watching the money spent on "truck stuff" ; )

 

[rhurey]

No prob. Everyone is on a budget these days, money saved is a good thing. Especially if the wife is watching the money spent on "truck stuff" ; )

What we need is for a surplus store to register their name as Et Syrplus so it shows up Etsy or something.

 

[DocPA]

Noisy NHC 250

Anybody else got a noisy NHC250 at idle? Mine sounds as one guy put it, like theres someone in there with a hammer beating on a coconut. Just a noisy banging sound. Oil sample was good so I'm not overly concerned but I'd like to know if it's just a normal noise for them.

 

[zxmedic]

Might need a valve adjustment and injectors .

 

[M35A2-AZ]

Maybe the air compressor or the fan clutch.

 

[swbradley1]

They do make a lot of noise just running at idle.

 

[EMD567]

I've never heard a quiet 250..............

 

[gem1410]

Many of mine have the same coconut sound---that sound is also present up to 1500 rpm--normal

 

[Carlo]

I would bet it's the compressor. Mine is noisy when pumping.

 

[EO2NMCB]

After driving a C15 cat for years, I don't find the NHC250 noisy at all.

 

[DJones]

Mine makes the same noise but not all the time.