86 951 Driver

I have read that the consensus is phosphate free coolant. I replacing the radiator today. My question is what kind of coolant should I use? Currently the standard green stuff is in there. Should I stick with that or drain it complete as best I can and refill with something else? My radiator is cracked so I would rather not have to flush it. Any ideas?

PorscheDoc

Prestone is just fine. Flush your system every couple of years and you won't have any issues. The issue is leaving coolant in for 15 years at a time.

67King

Is the car outside in below freezing temps? If not, distilled water with Water Wetter.

Fluidplay

+1 temps are always good even under hard, prolonged driving

86 951 Driver

I live in Kansas City, MO. The middle of the country. Coldest it gets here is about 0 degrees F. It does sit outside when I drive it to work. Its mostly a daily drive/weekend toy.

quinnfiske

I have been using VW/Audi blue. Available from dealerships. I also found it in a local auto parts store under the name Pentosin.

EVOMMM

dealer blue no problems+ water wetter

tjbreen

I ran water wetter and distilled for a few years then burned a valve and had to remove the head. There was some corrosion on the mating surfaces and passages. I now run some (2 to 3 cups) antifreeze in the system, partly because and can get to below 32 in my attached garage and partly for water pump lubrication and corrosion resistance.

86 951 Driver

Would they have that at NAPA?

mudbuddha

Has anyone use Mercedes Benz coolant? My shop used the clear coolant type...think it's for MB.

mtnman82

I just replaced the thermostat in my c230. I had the original blue/green coolant which you supposedly can't get here in the US in the system. When I drained it, the fluid still looked pristine after almost 8 years & 85K miles. I was told to use the orange Mercedes coolant available here in the US, and it is supposed to be good for just as long. The newer MB's have a redesigned cooling system and a special fluid that's supposed to go 15 years before replacing... I think I'd still change it out before then, just becasue I'm a little **** and I thought the ~8 years on the original stuf was excessive (you have to wonder how much antifreeze properties are left after 8 years). Bottom line, I think you'd be fine with MB coolant, but with as often as we seem to pull these cars apart I'm not sure longevity is a major concern.

zerMATT951

Prestone extended life - phosphate free, easy to get just about anywhere, orange.

86 951 Driver

I just worry about it being the Dex Cool stuff. Dex cool sucks. I am running the green stuff for now, but in the spring I might changed to a waterless coolant to get that last 1 HP on a stock motor.

quinnfiske

They had it on the shelf at my local NAPA store, but don't know if they all have it.

I have read that Dexcool is different stuff and formulated for newer cars. VW recommends a different coolant for new cars as well.

I would not use plain water in a street car. It is good to have the various additives that the coolant has. However, it is slippery when dumped on a race track, so it is a good idea to use plain water and water wetter for race cars.

mtnman82

FYI - I just found a bottle of Pentosin at my local Oreilly's auto. They said they keep one bottle in stock because every now and again someone will ask for it. They can order it if it's not on the shelf.