I am doing a coolant flush due to an intermittent dash indication of low coolant. When I flushed by opening the drain plug on the right hand side of the radiator, I expected > 2 gallons of coolant to flow out. Filling it into gallon containers I drained out about 70% of that.

The car is on flat ground. I find it unlikely that I would be that low on coolant given that the light came on for the first time on my previous drive. I turned the engine on and it did drain out more fluid.

Any suggestions on how I can try draining out more? Should I open the thermostat housing? I don't know what the previous coolant was and am trying to drain out everything before a refill.

 

To me, it's a poor design. I think (have never seen them myself - even though I have swapped engines in one of these cars) there are drain plugs for the water jackets in the heads somewhere up the underside of the engine, but I think they would be a real challenge to get to. I personally don't remember seeing them... On my 928, the plugs for the heads can be reached easily and every DROP of water can be removed,,, anyways

It becomes a math problem. Measure what came out in an empty gallon jug or two - if youre lucky and did the last flush you will have a basic ratio of coolant to water in the OLD coolant. If this is the first time you've done this in the car and another did the coolant swap before you, you will have to guess - maybe by the color of the coolant or the feel of the coolant when rubbing the liquid between your fingers.

Then try and mix your new batch on the side in another bin of some sort to get your right ratio - with what's left in the car in mind. It ain't no fun.

It is and isn't an exact science... All you can really do is try to get it right. What I have experienced is that when I run 50/50 or it leans on the side of more coolant to H2O, my 2002 runs hotter and a bit more erratic from 199 or so, up to 208 or 210, and I don't like it. When the ratio is more on the H20 side,,, seems a bit more stable and rarely goes past 202 204F... But that's just me.

See what others say.

 

Large drain plug on the left side of the block to the rear of the motor mount.(17mm hex plug)

Accessed from the left side between the wheel arch and steering rack area.(long extension and flex joint with 17mm hex key socket)

It uses the same seal as the oil gallery plug at the back of the engine.

 

Member Texas Dan did a good how-to on flushing the system:- see attached.

Ignore the references to the coolant he used - stick to the one you have already chosen.

 

Thanks. @JayJagJay @motorcarman @michaelh

I looked for the drain plug to the rear of the motor mount on the left, don't think that is in my reach (literally and figuratively ). I drained the system and measured exactly how much I am draining, It is close to 50% of the system capacity. Bit surprised that that is all it is. I had estimated 70%.



The color is getting lighter, above is from the most recent drain and below is from the first drain





Getting here was 3 drains - I'm guess I'm about 3 to 4 more drains from getting clear water thru the system. At which point I plan to top up with only concentrate. It has been time consuming drain - fill - drive - cool system - luckily it is the long weekend and I've nothing else to do. If not I might have given up by now.

I was following Texan Dan's notes - had the saved to dropbox when I was looking stuff up before starting. The only thing I have not done is to run pressurized tap water thru the system. Didn't want to do that - no sure if I want to.

 

This is a good fact... Thanks MCM...

 

Long tiring weekend - but I got clean water (or as clean as I can get it to) after 8 drains and refills. Purchased the metal thermostat housing and plan to replace that and refill with coolant sometime during the week. Appreciate everyone's help

 

I always spend the extra $70 or $80 to get the crossover at the same time.
The resin pipe gets deteriorated over time and needs new.