Block Heaters
 

Hi-Has anyone tried the block heater that fits in the lower raditor hose? With winter coming I would like to install a heater, but I don't think I want to try to remove a plug that's been in for 20 years. I don't understand how a heater in the lower rad. hose would help much. But if it does it would be a lot easier to install. Here in Maryland we do get a few extremly cold nights where my car would not start early in the morning.

I removed the drain plug no problem on my 87 and it had not been used in 20 years I am sure. I just replaced the rad on it and drained the block that way. So try and see if the plug moves, just don't over do it. Mine came out no problem and I also have a block heater.Block heaters certainly will work better. But this did not really answer your question....No idea if one is available. I assume you have a Mercedes as you mention and show nothing...

I have one. Haven't used it yet. With the thermostat closed, water circulation will be minimal but some heat should make it into the block.

See photo number 3 in this link for a picture of my heater.

http://www.peachparts.com/shopforum/showthread.php?t=160706&highlight=skid+plate

If you do a search of this forum for "block heater," you will get lots of information.

Thanks Guys

Here: http://dieselgiant.com/mercedesblockheaterinstall.htm

I've got one
 

Last winter I put one on my '76 W115 240D. I tried for a little while to get the existing (non-working) heater out, and gave up before I destroyed something or had to remove the starter. The hose-type seems to work just fine, convection currents distribute the heat pretty well, with the caveat that it doesn't get all that cold here (below 20 is unusual).

I got mine from dieselgiant. It even comes with a new hose. I had some trouble, in that the hose wasn't the correct one (it was about 6 inches too long), so I reused the old one. This really wasn't DG's fault, because I've looked and everything I saw listed the part number he sent. (There is a recent substitution). Since then I have seen a '75 240D and the thermostat/hose configuration is completely different. So I don't know if my car has been modified, or if it was a change in those last W115s. (for anyone with the same model reading this, my lower hose goes under the AC compressor from the passenger side. The '75 came over the top, IIRC)

Sorry for getting off track. I had some temperature sensors from Dallas Semiconductor (the MicroLAN type) so I wired a few up and ran some tests. I put sensors on the block next to the original heater, the lower hose, the hose going to the heater core, the oil pan and an ambient reading. There are some gaps, as the sensors would drop out or give a bogus reading. Maybe this will give you an idea of how it heats up. (the file is a .csv)