Block heater test? - Page 2 - PeachParts Mercedes-Benz Forum

mrsaxman99 · #16 11-18-2008, 05:44 PM

I also have a watt meter at my outlet. I plugged in my block heater for the first time, and it's not drawing any current at all. Is there a fuse or switch that I should check for?

Jeremy5848 · #17 11-18-2008, 06:46 PM

AFAIK, no fuse or switch in line with the block heater wiring. This doesn't guarantee that a PO added one . . .

You may have to crawl under and trace the cord from the plug to the block heater (passenger/right side of the block, just in front of the starter motor). It could have come unplugged, especially if it is NOT the factory cord, which has a screw-in retainer to keep the cord from coming unplugged. If the cord is in place and seems OK, then the block heater could have burned out (although that seems unlikely and I have never heard of one burning out).

Jeremy

Jeremy5848 · #18 11-18-2008, 06:52 PM

Quote:

Originally Posted by CougarMark67XR7

My 79' 300SD doesnt have a block heater. How hard is it to install??

Your engine may already have a block heater and just needs a cord. I don't know when Mrecedes started installing block heaters as a matter of course in all models. In W123 cars, it was an option – free at time of purchase, expensive later. W124 and later models had it installed at the factory. DOn't know about S-class cars.

There should be a removable steel plug in the water jacket, right side, down low and just ahead of the starter motor (oops, does the SD have starter motor on left or right?). Anyway, the plug can be a b*tch to remove after 30 years. Other than that, the installation is not too bad.

An easier option is to put a heater in the lower radiator hose. Diesel Giant sells a kit (I have one in my '85) or you can put the pieces together yourself. The radiator hose heater is not quite as efficient but it does work and is an easy DIY job whereas the block heater can be a bear. Question for the audience: did we once have a post about someone actually breaking the block trying to get that plug out???

Jeremy

tankowner · #19 11-18-2008, 10:56 PM

Quote:

Originally Posted by 300sdToronto

Plug it in when it's quiet around. You should hear a faint "singing" just like an electric kettle......

Yup, I agree - easiest way to know if your block heater is working is to plug it in and listern. Do it some place quiet so you can hear the faint sizzle and humming noise as it heats up. Easy to hear if you are under your car - like when you change your oil or something.

pawoSD · #20 11-18-2008, 11:27 PM

The power cords like to fall apart and get brittle where they connect to the heater, I'd replace the cord. Both of them on the old engine and donor engine of my dad's SD were showing the wires through at the heater area.....if we had plugged it in it would have promptly shorted out. We threw out both cords. He doesn't really need a block heater since the car is sleeping all winter.

compress ignite · #21 11-19-2008, 01:45 AM

Spark3542,
All I'm looking for from the Block portion of the Heater Plug is the ability to
Conduct Electrons.

KCM · #22 11-19-2008, 06:16 PM

Quote:

Originally Posted by babymog

Or plug it in, when you unplug it you should hear or see a faint spark (in the dark is easier).

Ditto! They take a lot of juice. A click can usually be heard, along with the visible spark. No special testers needed.

Jadavis · #23 11-20-2008, 07:29 AM

Quote:

Originally Posted by Jeremy5848

W124 and later models had it installed at the factory. Don't know about S-class cars.

Jeremy

My later model S (95 S350) had it installed already, but I bet you are talking about the 1985 and earlier SDs.

Quote:

Originally Posted by KCM

Ditto! They take a lot of juice. A click can usually be heard, along with the visible spark. No special testers needed.

Yes, but the Kill-A-Watt is inexpensive and can be used for other things. Put it on your entertainment system (TV, DVD Player, Surround sound) and see how much juice that sucks sitting around doing nothing.

They have the Kill-A-Watt at Harbor Freight now. It is the basic version for about $30.

-Jim

franklynb · #24 11-20-2008, 12:44 PM

Quote:

Originally Posted by Jeremy5848

.Question for the audience: did we once have a post about someone actually breaking the block trying to get that plug out??? Jeremy

With the engine out on my 616: I had to
1) weld up a 19mm hex drive, using the "drive end" of an old, unplated 13/16" plug socket as the "hex", and attaching it to an odd-sized 3/4" drive socket,
2) use a 24" long 3/4" drive breaker bar ,
3) stuffed inside a 2' long piece of 1" pipe,
4) stuffed inside a EIGHT FOOT long piece of sched 80 2" pipe, and
5) hanging all 180 pounds of me from the pipe, bouncing up and down!

It EVENTUALLY started backing out.

The engine was out of the car, with all the manifolds and starter removed. I had already tried a propane torch and a brand new 600 ft-lb air hammer at a sustained 120 psi -- to no avail.

I can't imagine doing this IN THE CAR, as the torque direction is toward the windshield, so how does one get ... lemme see ... 1,400 ft-lbs of torque on the thing ????

I had the whole engine and tranny chain-dogged to a large pallet to keep it from spinning off the floor. I'm not fond of hammering on cast iron to break it loose.

--frankb

C Holmes · #25 12-22-2009, 07:36 PM

Turns out my ol' wagon has a B heater, the end of the cord was bad and it was not working. New end and she starts like a summer day.

hanno · #26 12-23-2009, 09:01 AM

Test: check for continutity across the flats of the power plug. If you have it, you're done. If not, disconnect the cord at the heater, check heater for continuity. If none, replace heater. If you have continutity there, replace the cord.

Also, the heater will fail if you run a high concentration of anti-freeze. I was running 75% rather than 50%, lost 2 heaters (!) in two months. Went back to 50% and replacement heater still fine after 10+ years. Think it had to do with heat transfer (or lack of it) from the element to the coolant.

Graplr · #27 12-23-2009, 09:46 AM

I just wanted to clarify about 'feeling the valve cover' and radiator hose. When the temp gets cold (and my cold is 15F or lower) the valve cover or hoses do NOT feel warm. Maybe if it is plugged in at temps above 40F it may feel warm but mine has never felt warm. The cold wicks the heat from the edges of the engine away pretty quickly.

If the block is cold I can almost always hear the sizzle when I first plug it in.

Shawn T. W. · #28 12-23-2009, 09:57 AM

I use a lower rad hose heater 1500w! sure sizzles! This mornong 31 degrees plugged into a timer, been on for 1.25 hrs . . . 60c when I started it! Backside of head is very warm . . . of course the org heater that was not installed on my car would only be 400w, almost 1/4 the output. . . I use mine whenever the temps are forcast for less than 40, don't ussually see less than 15 here . . .

jason_rock · #29 01-06-2010, 08:18 PM

If you are looking for another block heater tester, a company from BC makes one and sells them on ebay for about 20 bucks with free shipping.

just type in "block heater status" tester in ebay.

Jason