Hey all! I'm getting ready to do the inline tstat mod and figured it was time to do coolant as well. I originally replaced the coolant when I got the vehicle along with a replacement factory tstat, new expansion bottle/cap, and new water pump. At the time I used prestone "yellow" and distilled water. I have since read up that these motors are supposed to use "orange" dexcool exclusively. A couple of questions:
1. Am i boned? was Prestone "yellow" a bad call?
2. If I'm going to do a fresh flush and fill, what is the best option going forward? Orange? Blue? stick with yellow?

 

a quick search here will show that the majority of us run and recommend the standard green, brand is irrelevant. Check out the sticky at the top of the d2 section for the inline thermostat mod. If nothing else replace the factory one with a factory 180 degree.

 

Yes. Search is your friend. I too use good ol' Prestone.

Pull the lower radiator hose and drain what you can. Reconnect the hose and refill the system with distilled water, bleeding the system according to the procedure in the RAVE. Take the truck for a drive for a few miles, just to circulate and mix what's in the system. Let the truck cool down and repeat the process until you can't see any color from the antifreeze. It usually takes two cycles for my truck, maybe three if you want to be sure you have all the old antifreeze out. At that point you have only, or mostly, distilled water in the system. Drain the system again and then fill it with Prestone Concentrate, not the 50/50 they sell.

You'll end up with a 50/50 mix since about half the water stays in the system when it's drained by pulling the lower hose. Take the truck for another drive of a few miles, and top it up with more Prestone Concentrate. This is what I have done every other year for the last decade plus.

 

Mine's filled with Porsche coolant because that's what I had when I did my flush. It works fine and is safe for alu blocks since 911 motors are aluminum as well. That said, I wouldn't recommend it because it's quite expensive when something like Zerex G40 would do the trick just as well.

 

There are nice block drains on both heads, near the back of the head on the drivers side and near the front of the head on the passenger side. Using the drains you get the sediment out of the engine block. Then you just have the water that can't drain out of the bottom of the radiator.

 

BMW coolant for mine from the dealer. About $30 and is specifically made for aluminum engines and components. I think Zerex makes it for them, so maybe consider Zerex too.

 

I use Audi/VW coolant because that's what I run in my S4. Just easier that way. Since I had my Turner engine installed it has been the only coolant type used. I actually flushed my old motor and ran that coolant as well.

 

I’m buying a D2 next week that belongs to the local LR Independent shops’ LR mechanic who’s become a good friend of mine (that’s a big asset btw… haha!).

It’s an ‘03 with about 30k miles on an AB top hat motor. Still running Dexcool.

As you would expect, he likes whatever LR spec’d for it, and says he’s never had bad experiences with Dexcool as long as it’s drained and replaced.

Id rather avoid Dexcool and just run the regular stuff. So going to do a flush after I get it sometime soon.

Ive read a bunch of threads on coolant flushing and it seems like the key is to flush with distilled water multiple times to get the Dexcool totally out. Any other recommendations?

 

Drain the block

 

The downside of Dexcool seems to be larger than the upside. For that reason I switched to green Prestone in the 2001 P38 I just bought. I flushed it several times and then used compressed air to blast out the last of the liquid (which was basically entirely water at that point)