Mark B.

Haven't heard of any problems with the in-hose units. And our mechanic, a crusty Eastern European with plenty of loyal customers in the area, wouldn't recommend it if there were problems with it.

He jokingly offered to give me a new block heater he guessed may still be laying around in his shop somewhere and offered to pay me if I install it myself.
No trips to the store in search of a 19mm allen wrench.....

I'll probably go with the in-hose setup, and as soon as freezing weather subsides remove the hose/heater setup and reinstall the regular hose.
When going back to the heater setup at the beginning of winter, the coolant could be changed at the same time after hot weather abuse.
Just a thought, and good luck.

I can think of one sure-fire way to check the current draw of my block heater: measure it with an AC current meter. If someone else gets a chance to check this before I get a chance to dig mine out of the toolbox, could you post it here?

Look on Ebay
Engine Heater for Mercedes Diesel
Item #242009826

It is 400 watt and NAPA P/N 605-3194 (Canadian made) are the ones I've installed are also 400 watt - I measured the current with both vehicles block heaters operating and it was 7.5 amps.

Quick reply, Dennis; thanks. With a 400W draw, no wonder I hear a good electrical arc every time I plug mine in

Thanks for the 400-Watt info.
It is now firmly etched into my brain.

Dennis is right. It takes a few hours for a block heater to warm up. Putting it on a timer like his daughters have done is a good idea.

Modern fuel injected cars that are tuned up, have a good battery and have synthetic motor oil in it, will usually have no problem starting in very cold climates (sub zero F).

Having said that, there are two advantages to having a block heater. 1. It's good insurance for starting and, 2. The car sure warms up a lot quicker.

There are many different types of car heaters on the market here in MN, but the most efficient and least costly to operate is the block heater (most now are 400 watts). If one can be installed on a car, they're the way to go.

Zerostats are made in Canada and the corporate headquarters are located in a suburb here.

By the way, why is it that block heaters can be a factory option on American cars, but not European cars? Hmmm...

Bill, you have me wondering if I can feed my block heater 240 VAC and get 800 watts of heating ... I wonder if there is a Euro block heater, and whether it has different resistance from a US version.

I have the girls plug in the block heater not only for the ease of starting in cold weather. Here in southern Washington, the rainly conditions coupled with a very steep gravel driveway and rural private road visibility can be poor. Being inexperienced drivers (by my standards, they think I'm wrong) and need every advantage possible. Having the use of heater defoster etc is a real plus. The turbo's have more trouble climbing out of the driveway cold than does the 240D. In fact my motorhome has to be towed in and out (coupled to my suburban)for traction.

[This message has been edited by Dennis Taylor (edited 01-25-2000).]

If you plug the 120VAC/400Watts block heater into a 240VAC outlet, according to my math, you will get 1600 watts of heating. If the heat cannot be removed by the coolent quickly, the heater will be damaged.

David

While we were in Florida last month, I left my '80 300SD plugged the whole time we were gone (two weeks). Also, if I drive another one of my cars down to Cincinnati for the week, I'll plug the diesel in and leave it until I drive it again. I've been doing this for a long time now, and I have yet to see any problems. One thing I do notice with block heaters is that when the car is in a garage, the heater does a considerably better job of keeping things nice and warm. I guess because you can factor another 20 degrees inside the garage. Anyways, my $0.02

------------------
Rgds,
Aaron Greenberg
MB technician
Precision Motorcars, Cincinnati, Ohio
'67 250SE Cabriolet
'77 450SL
'79 6.9 (SOLD)
'80 300SD
'85 380SE
'89 420SEL
'93 300E 2.8

I agree since.

If a 400 watt heater (load) on 120 volts would be 3.33 amps current and so resistance would be ~36 Ohms. (Mine measures 33.3 ohms)

With this resistance at 240 volt it would be a 1600 watt heater

Robert,

I think 400 watts pluged in for several hours would produce all the heat one should require.

I too would worry about having 1600 watts. This would probably shorten the life of the heater. And we've heard how difficult putting in a new one can be!

Fyi, I've seen several posts mentioning the need to periodically inspect the block heater to make sure it is not seeping coolant from the threads and retighten if necessary.

(Along with fast glow plugs, I'm having the shop intall an in-hose heater unit tomorrow.)

Bravo to Dennis Taylor who knows ohms law & P=IE. I always try to remember to check the blockheaters on the cars I get in and they are always ~35 ohms. The general rule of thumb is to have it plugged in for several hours when the temperature gets to < 20°F.
I have been able to start my '85 300DT (230,000 miles) at zero ° w/o being plugged in by preglowing it 4 times then cranking it until it runs smoothly, about 20-30 seconds.

Best advice is to put a factory block heater in (use a little heat as previously stated) and a 3/4 drive breaker and extension: 3/4 don't flex none!!

------------------

If you have a "Clark Tools" store anywhere nearby, I bet they will have the tool for you.