If you want to do a real flush and drain all of the coolant, you arent going to get out of undoing the block drain. There's a few quarts of coolant in there that wont get out by any other means.

Do a search for 'block drain' and there are some great pictures. Its a 19mm plug on the passenger side of the engine. Its about 6 inches forward of the starter, accessible from underneath.

Ive got it down now (I took one green shower and then decided there must be a better way) - car on ramps. 19mm 3/8" socket with 6" extension. Loosen the screw underneath a little. Then take the socket wrench off and leave the extension/ socket on the bolt. Kneel down in front of the passenger headlight and reach in and grab that extension and unscrew the drain. This way, you dont get wet, not even a little bit.

Someday when i have time I have pictures of all of this, I need to make pictorials of these things.

Good luck...
dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Exactly how would it just "pop out"?

I think you have heard incorrectly.....

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

You are thinking of the press in casting ("freeze") plugs. The block drain plug is a threaded plug. The only way it can "pop out unexpectedly" is if you forget to tighten it.

Thanks folks, for your replies. Yes, I was referring to the freeze plugs. I wasn't aware this was a threaded plug. Thanks so much for the advice and technique to loosen it, I will definitely incorporate draining the engine when I decide to do the citrus flush.

Do you all use Teflon tape when putting it back in, or does it seal well enough by itself?


Thanks again!

__________________
1983 300D (Hans)

Seals fine by itself. Dont over-torque for the next time.

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

I can't remember; does it take a copper sealing washer like so many other things on these cars? If so, you may or may not need one of those. I reused mine and it sealed fine.
There is a whole lotta fluid in that block. You will see how much when you drain it.

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

I'm guessing on the turbos it's much harder to reach than on the non-turbos--very easy to snake a ratchet under the EGR so no getting under the engine for that drain block plug.

On the wagon there wasn't a washer, but on the sedan there was an aluminum-looking washer. Will install a washer on the wagon next spring, but so far it's holding fine without one.

-noah

__________________
1980 300D (non-turbo, 421k miles)
1984 300TD (turbo, 305k miles)
1985 Vanagon (170k miles)

I used citric acid from a soap supply shop here in Seattle, Zenith Supplies (www.zenithsupplies.com). I used it on both cars with the same result--maybe it was the citric acid, but I figured citric acid is citric acid is citric acid...

Yes, I had just installed new thermostats prior to the flushes.

I'd say it was a LOT of crap, yes--the wagon clogged several times before it finally started flowing freely. Not as bad on the sedan, though. I was draining into a oil change pan and still saw cloudiness for a good five washes or so *after* getting the bulk of the crap out.

I didn't have overheating issues before the flush, so I'm not sure the chalk was present, or if it was some sort of reaction with the citric acid.

Good luck and stay warm!
-noah

__________________
1980 300D (non-turbo, 421k miles)
1984 300TD (turbo, 305k miles)
1985 Vanagon (170k miles)

For all who have been reading along...

Yesterday I flushed the system. Concurrently I mixed a 10% solution of citric acid and ran some experiments on it. I:

-heated it to boiling
-added some motor oil to it
-added some antifreeze to it

All of this with the same tap water that I got the white chalk with. No chalk, nothing created the precipitate.

CONCLUSION: The white chalk was IN the system to begin with. So, to test my hypothesis I ran another shot of citric acid solution in the radiator, following the FSM directions. Ran it up to 80C for five minutes as described in the FSM and drained. Trace amounts of white stuff, but the water was brown and had a bad smell. Point is the white stuff didnt re-occur. So the citrus flush got it all out, and it was in there to begin with.

What caused it? I found during the flush my monovalve had a tear and my aux pump wasnt working. My car is front Texas and heat was rarely used. So Im guessing between those things there was just a lot of gunk buildup in the core etc.

So hopefully I can finish the flush with dignity this week. I had to replace during the flush (that I didnt know about before)-

-water pump (weeped after day 1 of flush)
-radiator (neck snapped off)
-aux water pump (dead)
-monovalve diaphram (discovered this unclogging)
-expansion tank (saw a crack near the cap)

good luck and be ready for detours...
dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

it's like dumping acid in your engine

__________________
1987 420 sel

Finished the flush two weeks ago and now have a 1000 miles on the new components with 50% Zerex solution. All is well. No signs of chalk now, and the temp hangs at 85-90C, maybe drift to 95C when going 85 on the highway.

Now to fix the ACC system...right now I either have max heat, or no heat.

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Try replacing the foam tube to the heat sensor behind the glove box. -Remember we talked about this recently.

76 300D: Last Sunday, Syracuse NY. getting cold!
Process: Zerex G-05 and Zerex Flush worked for me this week.
No problems. Drained green coolant, flushed block and radiator w/ garden hose. Filled with water + Flush, ran 20 min. drained, flushed w / garden hose and all drains open for 10 min. Filled w/ garden hose,ran 20 min, drained, flushed again, then closed drains and filled wi 1.75 gal of Zerez G-05 and topped up with Distilled Water. No problems. good to -34F.
It is very important to drain the block. On my 300D, the Hex bolt engine block drain is easilly seen and loosened. You must drain the block this way. and remember to remove the bleed screw on top of the Tstat housing to aid the process.

hey Paul,

Thank you for reminding me. Its time to replace my CCU and see just how many of my vacuum pods work. Next weeks project...

dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car