Mike B

Opinions on the blue coolant available from VW and Audi?

Marine Blue

Andrew which green coolant are you referencing? There are many types out there these days and it would be helpful to know which ones are causing problems with our cars.

I ask because the Prestone "Mix with Any Coolant" has a green hue although it's been reccommended by many.

Earl Gillstrom

You got the correct answer many times. DRAIN THE BLOCK, flush with water and use ZEREX G05. G05 is the OEM AF used in all Fords and Chryslers. I have used it in many 928s for years and it works fine. Install 2 gallons (undiluted) first and then add distilled water to fill. That way you get the proper 50/50 ratio. DO NOT use the stuff with the water added. There is always some water left in the system after flushing and you end up with less than a 50/50 ratio.

worf928

This horse was most recently beaten here:

https://rennlist.com/forums/928-forum/404881-green-yellow-orange-which-coolant-is-right-for-our-cas-read-here.html

The Prestone "Mix with Any Color Coolant" is the Long-Life coolant Bill Ball refers to above. I venture to write that it, along with the Zerex G-05, have been given the Rennlist Seal of Approval (RSoA)

dr bob

The stuff I'm using now is the Zerex G-05. It's almost water-clear. Here in the tropical desert climate of SoCal I run a gallon in distilled water, plus one bottle of Water Wetter.

The Water Wetter helped immensely on my Explorer when it was doing summertime towing duty across the deserts to Arizona. Daytime air temps 120º-plus, with a trailer-load of water toys, black truck. Sitting at idle with the AC on max, the temp would drift up towards overheat on the gauge. Rev the engine slightly and the airflow would improve and avoid boilover, but still... A bottle of Water Wetter added, and suddenly it could sit for extended periods with the gauge just a little higher than normal. No worries at all about heating after that. So I'm a believer, based on my own first-hand experience. My 928 has never had any heating issues, but then again it's never been without Water Wetter in the years I've owned it. IMHO, it's about the cheapest $8 insurance you can buy.

worf928

Whoops... meant Bill Ball not DrB. Sorry Doc.

bd0nalds0n

When my car went to Greg Brown's shop with green coolant in it, it came back with blue coolant in it. Autobahn makes it. You can get it at the VW dealer although they charge ~$25/gal. for it.

dprantl

Blue coolant = most expensive blue dye you've ever seen.

Dan
'91 928GT S/C

Jfrahm

A Wet Vac will get that coolant out fast and easily without having to go after the block drains. Gets the vac nice and clean too. I use the radiator hose and put a drain pan underneath to catch what comes out when the hose gets pulled.

dr bob

Good idea on the wet-vac. You'll still want to pull the block drains to get any sediment out of there, but after the coolant is out a little bit of water flushed through there isn't nearly the same mess.

Bill Ball

Andrew: I don't know what using green had to do with your heads. I've used it almost exclusively and see no evidence of corrosion/erosion, at least as judged by the water pump. That's what Porsche put in the car. When I got my car with 70K miles, since it was exclusively Porsche serviced, that's what it had. I swallowed the Dex-cool Zeitgeist at the time and switched to it for one change, then after thinking about it, I went back to green stuff.

Bill Ball

How do you use the wet vac to get the water out of the water jacket around the cylinders? Do you thread a long hose into a low spot inside the block?

dr bob

Bill--

The wet-vac idea is to attach the hose to the top (non-thermostat) side, then open the block drains. The massive velocity of air rushing through the block drains will carry the remaining water out the top...

Seriously, putting a little negative pressure (it's all relative...) at one spot will draw a lot of the fluid out. I'd be tempted to try it at the top after draining the radiator and heads the 'normal' way. Flush with a LOT of water through the top hose into the block. Then open the block drains while using the business end of the wet-vac to try and capture the outflow.


I do the drain-and-flush-and-drain routine now, minus the wet-vac. I have a couple very large dishpan-like trays that go under the engine, so most of the draining fluid is captured there anyway. Any stray is wiped up with a towel. The floor is cleaned after these events anyway. For the most part, I concede that there's some cleanup, plan on washing the coveralls, etc.

Coolant is due for change early summer, and brake fluid is due about then too. Auto trans will come up end-of year. Might be time to just put the car up once, do everything, and call it a day. There's room for a couple cars in there at the same time, so maybe a mini-clinic is in order. Since I will have to wash the floor anyway. I still need to get that wheel bearing tool and do the rears. Might be a l-o-n-g day.