Quick Coolant Flush mixture question
 

This is my first time flushing my 05 987 S. Based on everything I have read I will not get all the old coolant out. Possibly only 4 or 5 of the 6 gallons. I will flush with distilled water which will mix with the remaining coolant then drain that out leaving over a gallon of diluted coolant in the car before I put my new 50/50 in.

My question is do I need to worry about the overall mix in the car being less than 50/50 because of the remaining coolant? Should I mix my new coolant possibly 60/40?
I could be over thinking this but I don’t want to screw it up.

Thanks for the any help!

I went 50/50 with my drain. You'll be fine.

Save the overthinking for mechanical stuff. :D

Ok thanks Starter986!
I just finished draining and got about 4 1/2 gallons out. With no drain plug it was a challenge to get the hoses off. The coolant was a green/brown color. I used a vacuum system to check for leaks and refilled with distilled water ran it up to temp now I am waiting for it to cool before draining it again changing the water pump, thermostat and belt then refill with 50/50.
So far so good
Cheers!

Yeah... those hoses can be sticky. It'll be easier next time (assuming a next time).

Likewise me.. although I have a drain plug. I, too, removed those rear coolant hoses. Also, I replaced the thermo and WP.

A vacuum system? Perfect. If the procedure properly was performed... you're good to go. However, I believe with the vacuum system you could have sucked/pushed out near every last ounce of old coolant? You didn't? Why?

The vacuum was just used to check for leaks and refill, not coolant removal. It worked very well.

To drain the coolant I just opened up the hoses and raised the front of the car along with setting the heat at max. After I drained the distilled water and removed the water pump and thermostat more came out. The water pump came out easily and was in good shape but the thermostat was much more difficult. It was installed with Torx Bolts instead of regular hex bolts so I had to make a trip to Harbor Freight to get sockets to remove them. Two of the bolts were hidden behind other hoses and the exhaust which were challenging. Tomorrow I will put the belt on refill it and hope for no leaks.
Time for a beer!

Hi Mark. Just yesterday i had my coolant replaced via a vacuum machine attached to the filler hole. (Was getting a second flush following valve work).
This thing sucked out 7L then replaced with a fresh 50/50. All in about 15mins.
Saved all the hassle. Nice clean job.

Perfect. I made the same HF run when I did my WP/thermo. ;)

You saved some cash! What's your next project?

Refilled the coolant this morning after using the vacuum to check for leaks then put the new belt on and ran it to make sure nothing came lose then put the panels back underneath, the hood, access panel and trim. Hopefully I will have no problems. My biggest concern is that I couldn’t get a torque wrench on most of the bolts on the thermostat and water pump so I hand tightened snug.

Next I will pull the Center Console, radio and some of the dash so I can tape up the air flow door that is coming apart sending bits of debris through the air vents. I am going to carbon fiber wrap the console while I have it off because mine is scratched up. I’m also going to carbon fiber wrap the plastic on the doors by the window switch.
I will try to post pictures but I have difficulty posting on this site.

Thanks for your help!

I probably should have taken mine in but I am pretty hard headed and cheap so I did it myself.....
The second time I drained it I got more out. A little more than 5 gallons.

If you don’t mind my asking how much did your flush cost? It definitely took me a long time and was a learning experience for an amateur like me.

Cheers

The flush and refill was £39

Same here... torque wrench challenges... hand tightened. I worried about it for a week or so... waiting for leaks... nothing. All good.

Yeah... the air flow... foam. Likewise, here. I'm looking forward to your writeup!

Cheers!