Block heater replacement Cummins C8.3 325 hp
After 22 years the factory block heater quit working. It knocked out the 20 amp circuit in the storage building and threw the breaker on the panel. The 110 electric supply line was severely damaged at the heater block. It was melted and removing it left it in pieces. Major corrosion at the two prongs on the block heater and meter indicated open circuit.
After looking at several YouTube videos of block heater replacement on Cummins 5.9, which is similar to the C8.3 block heater, I ordered a new block heater and cord from the local International dealer. Part numbers have not changed: cable, engine heater 3905113 and block heater 3918597. Once again, my local dealer had the parts in one day and the prices were better than I found online. There is an aftermarket heater at half price.
I drained the coolant at the radiator into a large Rubbermaid tub. Sprayed the bock heater with PB Blaster the day before. The heater goes into a freeze plug opening in the block driver's side below the exhaust manifold about mid-way down the engine. I accessed it from the rear engine cover opening standing on the cross member and leaning over into the compartment. The heater is held in place with a single hex bolt (3/16 allen wrench) that draws a backing plate attached to the heater and wedges the entire assembly it into the freeze plug opening. A mild spring holds the backing plate away from the heater so that you can swivel the heating element into the water passage and then draw it tight. The block is machined with a bevel and there is a rubber o ring pre-installed on the heater assembly. It took several tugs to get the hex bolt to start loosening but then turned easily. You don't want to fully remove the bolt because that would leave the backing plate inside the water passage. Used a pointed object to loosen the grunge around the heater assembly and then took a pair of vice grips to the EE plug housing and worked it loose, came right out. Assembly was the reverse, noting the original orientation of the block heater.
Refilled the radiator with the original Fleetguard OAT coolant that was two years old leaving the last pint or so behind in the tub with a few flakes of junk. I also changed the coolant filter before refilling. Ran the engine for about 10 to 15 minutes with the coolant reservoir cap off and could see air being purged. Stopped running the engine when the bubbles disappeared. I anticipate adding some more coolant as I removed more than went into the engine.
This morning ran the heater for 3 hours in 28-degree weather. Fired up on the second revolution drove 20 miles to new campsite.
Topic: Block heater replacement Cummins C8.3 325 hp