Hi all,

Not on my truck, but figured you guys would know anyway. My brother bought a used Focus with a factory block heater (frost plug style I assume.) Cord end was kinda melted (not sure if it layed on something hot or what), so he replaced it. Anyway, now that he has tried it out, he says after about an hour, cord isn't warm or anything but he hears a gurgling sound like a coffee pot.

Coolant level is full, no cooling system issues at all (engine runs at normal temp, doesn't use coolant, no leaks, good interior heat, etc.) In fact, car overall appears to have been very well maintained and is in great shape. Thought about just replacing it, but is in a PIA place on the firewall side of the engine so would rather not.

I have never 'heard' a block heater before. Localized boiling (perking) of coolant near the heater element? Wouldn't think that would be realistic anyway, particularly without low coolant, but I don't have an answer for him. Is this normal, bad or just odd?

Any thoughts would be appreciated.
Thanks, Mike

 

They usually make a sizzling sound at least that is how I interpret it.

 

Normal for it to make a sound like that, heck even with a electric water heater you can hear the elements heating the water.

Block heaters works exactly the same way.

Time to replace it is when it doesn't make that sound!

 

Thanks for the replies. Makes sense. Is just a heating element in liquid just like a coffee pot or water heater, as stated. No prior experience with the sound in that application, combined with the melted cord end, made me a little paranoid about it possibly being an overheating issue and a potential electrical fire hazard.

Thanks again,
Mike