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Faulty heat

My jeep heater continues to have sand like sediment cloging the heater core, even after many flushes and replacing the heater core and the radiator. the mechanic says this will probably continue unless I replace the engine. Please help!

Engine blocks are sand casted. Which means sand is formed to shape the block and molten cast iron is poured into the cast. Then once the block is casted and cools down, the casting operates on a vibrating belt to knock any sand out of the casting before its final cleaning. Sometimes all the sand isn’t removed from the casting and over time gets released as the engine is used plugging the cooling system.

I’ve disassembled engines and have found sand attached to the engine casting. But didn’t break loose. Just a big clump of sand.


What coolant are you using? Reason I ask is because dex cool can sludge is a known problem.

I agree with @Barkydog Don’t use Dexcool in engines that don’t call for it.

I think back-flushing the cooling system and replacing he coolant every other year, or in your case every year, might help. The heater core can off be backflushed separately, if that’s the main place the sediment is accumulating.