I drained the radiator and about a gallon of s****y brown used up coolant poured out. I thought that was all just fine, but I checked the (original ) user's manual, and apparently there was another 1.5 gallons of this crap inside of the engine block and trapped in other areas.

The Haynes told me that there was a nut/bolt/plug that needs to be removed from the engine block in order to allow complete drainage. Thanks for telling me, jerk, there wasn't a photo so I had to come to this forum with my tail between my legs "I do beseech you oh mighty Diesel Demigods, reveal unto me the location of this plug/bolt/nut." Anyway you d00ds were a real help, someone described to me the area where I would find it; and I did.

Alright, so I couldn't get this blasted plug/nut/bolt to loosen. I had to reach in at a weird angle and couldn't get enough leverage to really muscle it. I could have sprayed it with WD-40 or something, but whatever; I didn't think of it. Shut up.

Right, so, I did the next best thing. I started the engine and waited for the thermostat to purge all of the crap into the unplugged radiator.

DAME. Here I thought that I'd gotten it all. As soon as the temp gauge hit 80 degrees, the radiator started to piss out this disgusting brown coolant. I had it changed at a service station about 20K ago, but I guess that all they did was flush the radiator and forgot about the block, because this stuff was ripe for getting rid of, I can't believe that it cooled so well for being so filthy.

Anyway, I ran the engine like this until it started to get warmer than its usual running temp, then I closed the radiator and filled with water. Ran the engine for a while, then unplugged the radiator again. More yucky brown. I filled the radiator and ran the engine to purge it two more times. Once I'd gotten most of the water out I filled it with antifreeze and called it Kosher.

One thing that aggravated me, though; once I filled the radiator with that sexy green colored antifreeze, I started the engine and watched the contents of the radiator turn Brown AGAIN as the fluid cycled through. Whatever.

Why the hell do these cars take so much fluid? I mean....7 quarts of oil and 10 quarts of coolant for a 2.4 litre engine that turns out less than 70 HP...what is going on here?


Wow I wrote a lot. I'm going to go to bed now I think. Or something.

__________________
1982 240D.
My name is Michael, and I am an 18 year old binge-drinkin', cigar-smokin', novel-writin', all around unsavory and unnattractive guy. I tell long-winded stories, and I only shave once a week, although I've had to do it every day since I was 16.

May the Diesel Demigods have mercy on you.....
He knoweth not what he hath done!!!!

For what it's worth, I flushed both my 300D and 240D without removing the engine drain using (more or less) a method I read someplace in this forum. After draining the radiator, I also disconnected the heater supply hose from the engine (near the alternator) and got a good amount of coolant out. I then disconnected the heater supply hose upstream of the heater valve (mono valve on 300D) and turned on the heater control. After draining all I could, I used a hose to flush through the heater core and the engine, letting it drain out the connection near the alternator. Lots of old coolant came out. I also disconnected the top radiator hose and flushed through the engine that way. The only downside I noticed was I dumped a bunch of coolant and water right onto the alternator. It didn't damage the alternator, but it would probably be better to disconnect the other end of that hose. I then refilled with 50/50 MB coolant/ demin. water, leaving the upper hoses open to bleed as much air as possible. That was a few weeks ago and the new coolant is still the proper color, so I guess I got rid of all the green/brown junk.

It's almost impossible to properly flush these engines without removing the drain plug. Yes, some tenacious souls think they have done it, but, it requires multiple flushes and fills.

The reason is that the entire block remains filled with fluid, even if both the cylinder head and thermostat housing are completely removed from the engine. I recently had the pleasure of finding this out. Opening the plug lets about three quarts of fluid out on the garage floor.

You can't properly flush the block unless the thermostat is open. The thermostat won't remain open because the flushing water is too cold.

You could take the thermostat out of the engine and get a decent flush, but, I can't say that I've ever tried it.

BTW, the green antifreeze needs to be changed, I'm sorry to tell you. Zerex G-05 for you. See if you can crack that drain plug this time.

I agree that removing the plug is the correct way to do it, but the heater supply hose is upstream of the stat and will give you a flush path through the engine. I found that it will run clear after flushing for about a minute with a hose. Actually, I flushed, then ran for a day or two with pure water and citric acid flush, flushed again, and refilled with a 50/50 mixture. I suspect I stranded some water in the engine after the flush (by not removing the plug) so I flushed a couple of gallons of demin. water through to get rid of the tap water. I suspect my actual mixture is a little less than 50/50 because I didn't get the engine completely drained, but that's probably OK (I'll check it before winter). Come to think of it, removing the plug may be less work.

I didn't have the heart to tell him about the "sexy green colored antifreeze."

The heater supply hose runs from the head, throught the heater core and back to the thermostat housing. So, all of the flushing that is performed will be circulating fluid above the level of the thermostat housing. I agree that some exchange of fluid occurs within the block, if you do this for an extended period of time, but, I wouldn't want to lay odds that you get all the block fluid exchanged by this procedure.

He's not going to be very pleased.

Your probably right, I just didn't want to mess with the plug, especially on the turbo.

I don't blame you. I had the good fortune of having the manifolds and turbo sitting on the bench behind me.

Drain plug was a piece of cake. It's a rather stout plug and I can't imagine that a proper six point socket would ever round it over. In my case, the plug came out effortlessly. It might even be a brass plug, IIRC.

For all concerned, the plug is sitting about two inches forward of the end of the starter and about one inch above the top of the starter.

So far I've been able to avoid having that much good fortune, fortunately.

Then you've also avoided the good fortune of a cracked head. It's turned into quite the experience for the SD.

Ouch!

FWIW, if you happen to be changing the water pump, you can use its hole in the block as a flush port. I flushed the system on my 300SD in the midst of a water pump replacement a few weeks ago. The WP hole sits at the bottom of the water jacket, as you would expect.

__________________
80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

Is it something horribly detremental to leave the prestone gasser stuff in there?

What is Zerex and what is different about it? Where may I purchase it? (autozone?)


WHY AM I SO IGNORANT!?

__________________
1982 240D.
My name is Michael, and I am an 18 year old binge-drinkin', cigar-smokin', novel-writin', all around unsavory and unnattractive guy. I tell long-winded stories, and I only shave once a week, although I've had to do it every day since I was 16.

I don't think anything is horribly detrimental.

The general consensus around here is that the green stuff causes accelerated deterioration of the plastic parts in the system.

The Zerex is just a different glycol compound. It's recommended by many of the new car manufacturers these days. In fact, if you were to go to a M/B dealer, you would purchase M/B anti-freeze that is the same Zerex GO-5. So, clearly, M/B knows something about the green stuff that they don't care for. I'm sure Autozone would have it. I get it at PoopBoys. It's a bit pricey (about $10.00).

The owner's manual is your resource on these items. It will tell you to use only M-B anti-freeze. If you follow the manual, and buy the M-B anti-freeze, you can't go wrong. Most people don't even own the manual anymore.

The general consensus here is that the Zerex is identical to the M-B antifreeze.

I can't spell Detrimental!!!!

__________________
1982 240D.
My name is Michael, and I am an 18 year old binge-drinkin', cigar-smokin', novel-writin', all around unsavory and unnattractive guy. I tell long-winded stories, and I only shave once a week, although I've had to do it every day since I was 16.