Hi Folks,

Did my mechanic mess up my block heater installation? I purchased a 1000-watt tank-type block heater from JC Whitney for about $35. My mechanic said he could install that for $50, and probably $200 for the standard MBZ block heater, since it's harder to install. I opted for the JW Whitney one.

For anyone who doesn't know, the tank type block heater is a metal cylindrical tank about 4 inches in diameter and about 10 inches high, with a coolant in port on the bottom side and a coolant out port on the top. It has a built in thermostat and the manufacturer claims that in about 2 hours, the coolant in the system should be about 140F/60C. It works via the thermosiphoning principle, in that it heats the coolant, which then rises through the block and then as it cools descends through the circuit to be sucked into the block heater again.

Anyway, here's a picture of their installation. They charged me $115, more than twice what they said it would cost, because they found it very hard to do. It seems like they didn't follow the instructions that came with it at all. They mounted it VERY high in the engine compartment, and the out port leads to a high loop. The mechanic warned me that the loop was so high that if coolant in the radiator expansion tank dipped below the level of the loop "you could start a fire."

The instructions specifically say not to have any loop above the heater where hot coolant could collect.

When I plugged it in and left it for 3 hours, the temperature of the block was only 10 deg F above ambient (80F, ambient 70F). The temp gauge on the dash, when I put the car in Run, read nothing. The loop right above the block heater was 120F, but 3 inches down towards the engine on that hose, it was cool. Also, the hose attached to the bottom was hot, which the instructions warn is a sign of it not being configured correctly.

Shouldn't my block get hotter? Should I take it back to them? Should I ask them to fix it? Any chance they'll fix it for free? Should I just forget using this kind of block heater and have them install the OEM one?

Here's a picture of the installation. The block heater is the silver cylinder in front of the expansion tank.

Thanks!

Attached Thumbnails

 

__________________
==========================
Aaron
'84 300D 267,000 - Running WVO - Rice Bran Oil - Mmmmmm, fishy...
==========================