3.9L Cummins block heater question

[PHS79]

This isn't for a tractor, but for the motor in our telehandler forklift. It has a 3.9L Cummins (its the 4 cyl version of the 5.9L motor found in Dodge trucks and hundreds of thousands of other applications) and the block heater has gone out. I have done block heaters before, but not one with a setup like this. Has anyone ever replaced the block heater on a 3.9 or 5.9L Cummins? Any pointers before I tear into this on Monday?

 

[Craig Clayton]

Have fun, I think you already have taken the bull by the horns.
Craig Clayton

 

[brokenot]

We have several 3.9 engines in the fleet. There are two varieties of block heaters used on them, depending on the year. Pre-2002 or thereabouts, a standard frost plug style heater is used. I think the frost plug style heater is 58 mm in diameter, and the hole it goes in is semi-concealed by the starter. Easiest thing to do is unbolt the starter and lay it out of the way. Simple job to do.

Later engines use a 3/4" NPT thread-in heater. Also an easy install. The thread-in style replaces a plug in the block to the rear and maybe slightly above the back end of the starter. Plenty of room on these type....no need to remove anything usually.

 

[some zilch]

i just did one in a case loader; same 4 cyl cummins, and it was about as straight-forward as possible. i didnt unbolt anything to get at it. it was freeze plug style, and took all of 10 minutes to complete the job

 

[PHS79]

Thanks! The lift is a late 90's and has the big frost plug style with the allen wrench bolt in the center of it. With where the motor sits in the lift I did notice that I will have to remove the starter and also a saftey shield.

The one thing that I was wondering is what is the allen bolt actually attached to? How much do I have to loosen it? Any little tricks to this I should know?

The parts house didn't have the block heater on hand, but will be delivering it to the shop first thing Monday morning. If I had the part in hand I may not be asking what may be very simple questions, but being that I am going into this somewhat blind right now I figure its better to ask.

Thanks again guys!!

 

[shaley]

The allen screw is attached to a sheet metal wing ears sorta like a dry wall toggle anchor. See Picture
Amazon.com: Kat's 11410 400 Watt 50mm Frost Plug Heater: Automotive
You may have to bend the ears back in with a screw driver in order to get it back out of the hole. Clean the freeze plug hole and use some o-ring lube. It has to hold back 15 psi.
Don't forget to drain the antifreeze

 

[PHS79]

The allen screw is attached to a sheet metal wing ears sorta like a dry wall toggle anchor. See Picture
Amazon.com: Kat's 11410 400 Watt 50mm Frost Plug Heater: Automotive
You may have to bend the ears back in with a screw driver in order to get it back out of the hole. Clean the freeze plug hole and use some o-ring lube. It has to hold back 15 psi.
Don't forget to drain the antifreeze

Great, thanks for the info!!! I am sure it would have been simple to figure out if I had the part in hand, but since I wont see it until Monday, I just didn't want to be too surprised at what I get.

Thanks again guys!!

 

[QueBota]

Maybe too late but it is a good idea to run the engine a couple of times before plugging in the heater. In some cases the block heater can end up sitting in an air pocket and the element could be damaged if not completely submerged when it gets hot.

Dave

 

[PHS79]

I ended up getting the heater swapped out today, I ended up having to plow snow on Monday. It would have been a pretty thing, but with where the motor is located in the lift it was kinda a PITA. It would have been a whole lot easier, but someone ran off with the 3/8" drive 6" extension out of the tool set in my work truck. Now I just have to get the lift to start, it is very cold blooded and over night temps have been near 0*F and during the day it has only been around 15*F. I was going to ether it today to get her started, but someone also ran off with the ether out of my truck. It looks like I am going to have to start locking up things around the shop and check over peoples trucks to find what else I am missing that I haven't found out about yet.:thumbsup:

Maybe too late but it is a good idea to run the engine a couple of times before plugging in the heater. In some cases the block heater can end up sitting in an air pocket and the element could be damaged if not completely submerged when it gets hot.

Dave

Thanks for the advice, that is exactly what I am going to do, as soon as I manage to get the darn thing started. Hopefully tomorrow all will be good again...

 

[PoorMansCat]

I was going to ether it today to get her started, but someone also ran off with the ether out of my truck..:thumbsup:

GAS RAG!!!!!... If you don't have any unleaded handy, you can use a portable butane torch.. !!
Just watch the grid heater if it has one.