There are a few threaded plugs on the block below the exaust manifold and I want to use one to draw cold coolant from for my tank heater I have. I want to draw it from the block and return it into the head in one of the NPTF plugs at the top of the head. Does anyone know what size and thread they are? I want to get a fitting to put a hose on but I need to have the fitting beore I begin the project so I cant take it out till I have the fitting in hand to replace it.

 

I'd go to Dodge and get a new plug to measure threads on.

 

They want $15 for it. Ime not paying $15 to find out what thread it is. I figured someone on here would know but apearently not. Dealer is no healp. They just say its a threaded plug and have no idea what size. That and they said it would have to come from Detroit. There are none in the Minniapolis parts center so it would take a while to get. I am realy trying to avoid haveing my truck down for any amount of time because its my only vehicle. I want the fitting in hand when I pull the factory plug.

 

Any Cummins shops in your area? If so, they may be able to tell you or provide a cheaper plug. Remember only the shell around the engine was made by Dodge.

 

There all an hour away or more. I am gona try calling a few tomarow though.

 

Its M18x1.50, measured up the plug that I e@mailed you awhile ago. Sorry didnt see your post. It takes a 8mm allen socket to remove, 5/16 was kinda loose. The fitting that you will want it M18x1.50 male with 1/2npt female thread. Also need to get a sealing washer. If you cant get 1, I can mail you one, its around $12cdn for fitting with washer. Also cummins has no clue what size it is, other than its a plug. I already went thru this with them. I had to drain coolant, remove plug, went to local hyd store, got what I needed & ordered it up, had it next day.

 

Oh. I meant I'd measure the plug when they handed it to me, then I'd give it back to them. Or buy the thing, take it to a hardware store, match up what you need and then return the plug.

 

Awsome. Thanks. I figured you would find this thread adventualy. I may be able to find one at work if I look hard enough. If not I will definatly be able to get it threw there.
So long as I have to drain the coolant I am gona change it while ime at it. I have almost 100,000 miles on the truck so its abought time. That and while its empty I am gona change the little hose that has been leaking lately. There is a metal line coming off the water pump going to the oil cooler that has a little chunk of rubber hose in it presumable to allow flex. Its rite behind the turbo and leaks a little this winter. I tightened the clamps but it still leaks a little so I am gona replace it while I have the chance.