Where is that stinking COOLANT drain plug? =)

[SmartKCar]

I'm changing out the COOLANT in the smart and can't seem to find the drain plug. Called the dealer, they don't know, service manual doesn't say.
Help?!
Thanks guys!

[jwight]

First, I don't know. Second, why change it? Third, pages 39 and 40 in the Tech Manual discuss the cooling system. There is a coolant hose at the engine which is disconnected to bleed the system. However, I'm guessing (operative word) the radiator has a drain plug on it. If you find out for sure where the drain is please let us know.

http://scp-parts.com/pdf/2008fortwotech.pdf

[homeslice]

Factory coolant is never good. I buy a gallon of the Amsoil coolant which lasts up to a whopping 250,000 miles and is non-toxic. Then that's the last time I ever have to mess with it.

You should buy one of those service manual CD-ROM's on eBay for the smart so you can service your own vehicle.

[Duckhunter]

Originally Posted by homeslice

Factory coolant is never good. I buy a gallon of the Amsoil coolant which lasts up to a whopping 250,000 miles and is non-toxic. Then that's the last time I ever have to mess with it.

You should buy one of those service manual CD-ROM's on eBay for the smart so you can service your own vehicle.

Do you sell that wonder coolant?

[Old smart]

Watching.

BTW, the smart approved coolants are:

"Antifreeze/Coolant
Specification MB 325.0
Mobil Permazone Antifreeze/Coolant (green)
Mobil Permazone 50/50 Prediluted (green)
Old World Industries EURO Peak Coolant/Antifreeze (amber)
Valvoline/Zerex G05 (yellow)
Valvoline/Zerex G48 (blue)
BASF Glysantin G05" (yellow)

N.B. Investigation has so far revealed that the above products are not over-the-counter at the U.S. parts places, but distributed to Euro car dealers only.

Add. More investigation reveals two coolants available in the U.S. that, for what it's worth, are M-B approved: Mobil Delvac Extended Life (green) and Peak Global Lifetime (amber). The approval says MB DBL 7700 not MB 325.0, but 325 is actually "Page 325.0" of M-B publiction DBL 7700.20. Both are suitable for European cars (no phosphates) and Asian cars (no silicates). The deal with phosphates in Europe is that the common hard water there causes the phosphates to percipitate out and compromising the coolant's effectiveness, and silicates are contrary to the Japanese JASO standards to prevent waterpump wear.

M-B's own proprietary coolant (P/N BQ 1 03 0002) is made by Valvoline (clear). Based upon the blue color of my coolant I would presume it is a factory fill of Valvoline/Zerex G48 or Glysantin G48.

[smartSEATTLE]

The picture is a little difficult to figure out but it is located on the back of the engine. The little silver plug with the blue mark on it is the drain. Not the sensor but the plug in the block.

Word of caution, it is VERY easy to get an air bubble trapped in the upper portion of the head right by the coolant temp sensor, it this happens the vehicle will over heat.

[jwight]

Thanks for the photo; think I will leave the drain plug alone.

[jonnysan]

Here is a test that I personally did on my brand new Honda Prelude. It was an '84 model and proved to be probably the best car I have ever had in terms of reliability. I hope the Smart can do as well.
Anyway, thru that entire 16 year time period I never changed the coolant in the car but simply added small amounts as needed. I put 395K miles on it..same engine, same clutch, 4 timing belts and other normal wear items. I had to change the radiator at 250K miles as it rusted out thanks to Upstate NY Winters. I strained the coolant that I removed and put it back into the car.
One thing that I did do religiously was change the thermostat whenever the operating temp showed too low a temp in Winter or too high a temp in Summer. That was usually done every couple of years and these are 35-40K miles years I talking about here. Every time I removed the thermostat housing to replace the thermostat, I'd inspect the interior of the water jacket (aluminum) and it was always clean as can be and not corroded OR ERODED even the slightest bit.
After 16 years of service, I surmised that changing coolant was just another way to support the HUMONGOUSLY sized internal combustion engine $$$$ machine. As long as the engine ran in the normal range and the inside of the cooling system remained clean, why change it? Never had a freeze up, overheat or anything else like that with that car.

FWIW, I never changed one hose on that car either in all that time but that's a different test and story.

Don't take the word of your friendly antifreeze coolant peddler when it comes to changing/flushing out the coolant system...HE SELLS THE STUFF!!!

[homeslice]

I would never listen to that at all. Coolant also acts as a lubricant. I've seen Dexcool turn all sludgy. You got very lucky. Some people do. Most people don't. Just like some people who never change their transmission fluid and get lucky while the rest are spending $2,000 on rebuilding or replacing their transmission.

It's very inexpensive to change coolant. For my case, $20 every 250,000 miles is simply not worth the risk. $20 is chump change compared to spending $1,000 to overhaul an engine.

[mdfortwoguy]

Originally Posted by homeslice

Factory coolant is never good. I buy a gallon of the Amsoil coolant which lasts up to a whopping 250,000 miles and is non-toxic. Then that's the last time I ever have to mess with it.

First off... please don't turn this into a downhill Amsoil argument again.

You should buy one of those service manual CD-ROM's on eBay for the smart so you can service your own vehicle.

Second - I wouldn't trust one of these as far as I could fling it. These cars haven't been around long enough for a good 3rd party manual, and anything that may be EU sourced isn't going to cover a lot of the North American specific parts of the smart.