Coolant help
 

Hey guys! I have a 2000 MC 3.8. I was getting ready to drain the water out of it and replace it with dexcool as I was a lil short on cash when I added the water. I was just wondering if I have to bleed the air out of the system after I do this. Also I was wondering how much coolant it holds, I couldn't find anything in the manual about that. Thanks for any help!

Yes, you have to bleed it at the tiny hex screw on top of the thermostatic housing. You'll probably need to do it several times. Do it with engine warm and heater on. Hope you used distilled water mixed with the coolant. Tap water has impurities and minerals in it that will shorten the life of your cooling system parts.
The cooling system capacity is 11.7 qts., but that's with a completely dry system. You can't get it all out with just a drain and refill. If you're doing a drain, flush and fill you'll need one gallon of concentrated Dexcool and a gallon of distilled water. Best to buy 2 gallons of water in case you need a bit more. Should be about a 50/50 mix.

Yes I found out when doing this that there are knock sensors or something that you must take out of the block to drain the coolant in the water jackets after doing the flush to get all of the old fluid out. A real pain, I was able to get the front one out but couldn't even reach the back one!

Are you pulling our chain? That comes across as a bit much to clear a system of old coolant. Seems like running the engine and doing the regular flush method would be adequate. Don't know that I have ever seen a shop remove knock sensors doing a coolant flush / change. Your description may be a technical by the book method for a purist. I tend to think any remaining old coolant would be minimal and never adversely affect the new coolant mixture ratio or performance. But that is just my thinking.

Depends on how contaminated your old coolant is I suppose. I have flushed my old car twice and still find chunks of brown dexcool floating around in there. If a shop had a pressure system they can get all the old stuff out but for guys doing it in their driveway that's the only way to get the old stuff out of the block. I'm thinking because I couldn't pull the back plug that's why I still had the brown clumps of dexcool in there.