The Worlds Slowest Coolant Change Pt. 2

"MM54" (mm54mk2)
08/20/2015 at 19:27 • Filed to: None

As you may remember from my !!!error: Indecipherable SUB-paragraph formatting!!! I’m changing the coolant for the first time in an unknown length of time/miles in my car a gallon or two at a time. The first round was apple cider, this round is tea with cream.

The marked difference that I doubt one gallon of distilled and 5 days water made between the two is that the first gallon was drained after the car sat overnight, and this second gallon was about two hours after I got home from work. The first gallon has a lot of precipitate in the bottom of the jugs now, and I suspect this second will have even more since it’s still suspended in the “coolant” which was sticky where it dripped on me.

As to why I’m going a gallon (or two, now that I have two empty gallon jugs from the water I’ve put in) at a time - for various reasons, I can’t remove my thermostat without risking needing a new intake (corrosion-related, of course) to properly flush the system, and I can’t drain the block normally because one plug is inaccessible with the motor mount installed, and the other one is as rusty as everything else. The leaves me to my plan, which it seems a lot of others have done - drain some and refill with distilled water regularly until it comes out clean-enough.

Then, through the mathemagic known as addition (the whole system holds ~4gal and the radiator/hoses are 2 of that), it’s a matter of putting 2 gallons of straight antifreeze into the radiator, and once it’s mixed for a couple days, fine tune with the hydrometer sitting somewhere in my box of rarely-used-tools.

DISCUSSION (15)

Urambo Tauro > MM54
08/20/2015 at 19:42

This a Crown Vic? Where are you draining it from?

Out of a 14-quart capacity system, my Thunderbird manages to drain about 2 gallons at a time when I pull the lower radiator hose. I find that about 4 “rinse cycles” seems to get it running fairly clear.

MM54 > Urambo Tauro
08/20/2015 at 19:47

Yep - 2002 P71. I’m draining from the petcock on the radiator through about a foot of tube. The knob itself leaks terribly so I have to keep pressure on it or as much goes on the ground as goes down the tube...

I’ve only been doing 1 gallon since I only had a gallon’s worth of empty containers on hand, but now that I have two empty water jugs I’ll use those. The forums claim you get about 2 gallons if you let it run the whole way down from the petcock. Based on the condition of, well, everything on this car when I got it, I doubt this coolant has ever been changed. If I’m lucky, it’ll eat up less than 10 gallons of water before its clean-ish.

Urambo Tauro > MM54
08/20/2015 at 20:01

Distilled water is cheap. But I can understand not wanting to drain it half a dozen times.

The thermostat’s on top, right? I had to replace my intake because the coolant crossover was plastic, originally. All the plastic ones eventually crack. What is the corrosion issue you’re worried about?

Nisman > MM54
08/20/2015 at 20:01

Basically how I did it in my Maxima. I got all of the fluid out, couldn’t get the correct amount in. Had to run it carefully for a few days and add to the reservoir until it no longer drained the reservoir. What a huge pain in my ass.

MM54 > Urambo Tauro
08/20/2015 at 20:06

Yep, 88 cents a gallon I can run tons through before the cost is a factor. It’s just a hassle.

The ‘stat is easy enough to get at - I did replace it about two years ago when it stuck open. In doing so I discovered that the threads of the bolt that hold the thermostat housing to the intake were corroded enough that half the threads came out with them, and going back together (post-clean-up) it was way tighter than it should be. I suspect if I take it apart again, those threads may be no more.

At least I have the metal crossover.

MM54 > Nisman
08/20/2015 at 20:09

This is a really easy system where the reservoir is part of the pressure system, and is T’ed into the lower rad hose. It even burps itself after you drain and refill it (the only point that holds air is about 1/4 of the upper hose).

Urambo Tauro > MM54
08/20/2015 at 20:27

Part of the reason I’m such a big fan of using anti-seize.

Yeah, sounds cross-threaded. Hopefully that bolt will hold as long as you need it to.

AM > MM54
08/20/2015 at 21:24

My truck sort of just got a coolant flush. By sort of I mean it all leaked out. It was coming out crystal clear though and I haven’t done one coolant flush in the 140k I put on it.

MM54 > Urambo Tauro
08/20/2015 at 21:26

I too like to put antiseize on just about everything. Sadly, factories (and previous owners) don’t.

MM54 > AM
08/20/2015 at 21:28

Impressive. I’m pretty sure this has had the gold and green stuff mixed in it. The cap asks for gold (with a big X over pink) but there are green hues in the stuff I’m draining when I hold it up to the light.

AM > MM54
08/20/2015 at 21:32

Must have been filled with green at one point, possible it got low and that’s all they had available?

Mines a GM so it has to be the red/pink “GM Approved” Dexcool.

MM54 > AM
08/20/2015 at 21:35

It would have come from the factory with Motorcraft Gold, and like I mentioned the cap requests a yellow-liquid, not a pink (go away dexcool, nobody likes you). No mention of the green but I’m pretty sure it got in there. That’s what’s going in when I’m done flushing it, too.

AM > MM54
08/20/2015 at 21:51

Dexcool is a horrible product but at 240k km theres no point switching to green. Whatever damage was going to happen, already did (I just replaced water pump).

deekster_caddy > MM54
09/15/2015 at 21:25

I will never understand why any automotive engineer thinks putting steel bolts into aluminum castings without some kind of corrosion preventative is a good idea. Anti-sieze at minimun, heli-coil should be OEM. So many broken bolts. So... many...

deekster_caddy > AM
09/15/2015 at 21:27

Dexcool is just misunderstood! Change it every 5 years or 100K miles like the factory told you to and there aren’t any problems. But after that, it becomes nastily acidic and melts plastic. Unfortunately GM chose to use a lot of plastic engine parts that come in contact with the coolant. Whoops.