Howdy guys, Like a dummy I never checked the manual for proper coolant type and I've been topping off with the universal Prestone stuff. I really don't know how bad that is for our cooling systems but after 60k miles I finally realized we require a specific coolant! Today I got the right stuff... Zerex G-05 from Napa... and I'm trying to replace my coolant now. I know there's a petcock on the radiator for draining... I think thats on the lower passenger side... but I can't find the coolant drain plugs on the engine block. There's supposed to be two hex plugs I think... somewhere near the center front of the engine? Does anyone know where they are and what size hex I'll need? I'm not doing a flush, just a drain of the old (wrong) coolant and replacement with some new. I'm not familiar with how to make sure I get all of the old stuff out and any tips would be appreciated.
The block plugs are on both sides of the block, towards the rear. You probably have to pull the starter to reach the passenger side one. I've only pulled them with the motor on a stand, not in the frame. They're standard sized plugs (not metric). From what I remember, they're 9/16".
So... how do I get the coolant out of the heater core? Danka Senor. Thanks Dave but that "universal" pic of the block drain plug is what confused me in the first place! I like the sm quite a bit, especially the organization of the electrical diagrams, but they kinda got lazy in writing the cooling section
hahahaha I'm feeling pretty stupid not knowing much about this process. I'm thinking two things, after I drain the radiator and block... 1. I'll run the car for a few instants and hope air in the system will be enough to move the remaining coolant out of the heater... but will this burn up my water pump? Will it even work? - or - 2. I'll fill with distilled water and then run the car for a bit. This will definitely push coolant out of the heater and now I'll have a diluted mixture of the old coolant in there. I guess I could drain and repeat with water until clean. I think I'll go the #2 route, it's actually how the sm suggests we clean the cooling system... just seems like a time consuming pita.
The heater core sits up pretty high as compared to the block plugs and its lines go right into the water pump. I've never had any coolant come out of the heater core after draining from the petcock. I assume that it gravity drains or is siphoned out. If I were you, I wouldn't worry about the heater core. I definitely would NOT run the car without at least water in the motor and water pump.
So I pull the car up on my little ramps... poop the hood and loosen the coolant pressure cap... then get my bucket and the small monkey wrench. I crawl under... carefully place the bucket under the radiator drain hose.. and loosen the petcock expecting as deluge of coolant to come rushing out. NOTHING. Not one drop. WTH? I even started the car for a bit, still nothing.
Are you sure you got the petcock open? I've always had to use a special socket that my buddy has to get it open.
Well, it turns 90* ccw fairly easily. If I put more pressure on it, to try and turn it further, there's a lot of resistance. How far do I need to turn this thing?
Hmmm. That sounds right. Do you have compressed air? Sometimes sediment in the coolant collects in the bottom of the radiator. If you can, open the petcock and then blow some air back through the tube to try and get it flowing.
Ahh good tip there. I don't have compressed air but I can stop by a local shop and give that a try. Thanks for the sanity check.
If it is indeed open and plugged with sediment, just use a paper clip bent scientifically just so, or whatever else you can find, and give the hole a little in-and-out just like back in high school. That should move or loosen whatever is plugging you up. I can't remember how the petcock works but maybe you don't have a direct line into the radiator so compressed air may be better. If the petcock base is threaded in to the radiator you could always just unscrew the whole thing...then you know you're open for sure
With all this petcock and in-and-out talk...i'm gettin horny. If I remember right, you can turn the petcock more than 90 degrees. I just use a good pair of chanel locks. To flush the whole system i removed the thermostat, replace gasket, replaced water neck, drained via petcock, fill with water leaving drain open, start motor and kept water flowing in and through the system for sufficient amount of time (until only clear water drains out). Let cool. Close drain, fill with coolant, crank motor and get to temp. Let cool, replace thermostat with gasket, top off with coolant.
Honestly if you really think about it just topping off with the wrong coolant isn't going to effect much. The total volume of the system is much much greater than what you are adding in. I would say that you are now on prestones maintenance schedule not the mopar schedule till you change it out. Still 60k is a good number to do a coolant drain. Also keep in mind when these motors were engineered they take into account standard draining and filling procedures (meaning residuals and such). So simply following the procedures they have set up and you should be just fine.
Well gents, the patient is awake and doing fine thanks to your help. After scientifically bending a probe , it became clear that the petcock indeed wasn't open. Turning to 180* ccw did the trick. I do believe it'll actually turn further and eventually screw itself all the way out as it's some kind of worm gear. But I've read of people having problems with reinstalling so I didn't push my luck further than 180*. This drain valve is pretty tight, and if you have the special tool (if there is one) then that's ideal, but channel locks or pliers will work too, it's just a bitch cuz there's not much room to operate. After warming the car to get the tstat open I idled her with the drain open, filling the coolant tank with distilled water as it got low. After about 7 gallons of water it started running pretty clear and at one point the coolant (water) boiled over out of the open coolant tank. At that point it was pretty clear that the system was pretty much filled with water only. I shut the car off, let the radiator drain, and closed the drain valve. After the drain, the instructions posted here worked like a charm, thanks Dave! I had to remove my intake to open the air bleeder... and it was at this point that I realized I had no idea what mixture percentage I'd need due to not knowing how much water was left in the heater core and engine block. I took a swag at 70/30 (coolant/water) and began the fill. Eventually a trickle of coolant began to come out of the air bleeder, spilling onto the accessory belt (I didn't bother getting the barbed fitting and 4ft tube). After going for a short drive to circulate and mix it all up, I checked with the magical Prestone coolant tester... and it was right around a 50/50 mixture. Are these accurate?? I agree that topping off shouldn't have much of an effect, I just want the piece of mind knowing that I have a full correct fill. Also lately I seem to be using coolant, ever so slightly, and as I'm tracking this I want to know it's the right stuff in there. Dookie, here's a lil sumsum for ya if you weren't horny anymore. I think her shirt says "dookie"
