Pro tip: stop buying cheap block heaters from Amazon

I learned this one the hard way last winter. Bought a magnetic block heater off Amazon for 25 bucks, figured it would do the job for my old Cummins 5.9. Stuck it on the oil pan and left it overnight. Came out to a frozen engine anyway and the heater had fallen off sometime during the night. Lost a whole day of work waiting for a tow and then another 60 bucks for a proper frost plug heater from the Napa in Billings. The cheap one just couldn't hold a tight enough seal with the magnet, especially with road grime on the pan. Has anyone else had bad luck with those magnetic stick-on heaters or is it just me?

2 comments

2 Comments

kelly.daniel1mo ago

That 60 bucks for a proper frost plug heater from Napa sounds about right. I had a similar issue with a magnetic heater on my old 7.3 Powerstroke. The magnet just would not stay put no matter how clean the pan was. Did you have any trouble getting the frost plug heater installed, or did you have a shop do it? Ive heard those can be a pain to tap into the block without cracking something.

vera_lewis1mo ago

Hang on, you lost a whole day of work because of that thing? That hurts just reading it. My neighbor stuck one of those cheap magnet heaters on his old Ford and it did the same thing, fell right off while he was sleeping. He even wiped the oil pan down with brake cleaner first and it still wouldn't hold. For 25 bucks, that's a hard lesson. Bet you won't make that mistake again.