![]() ![]() GM engines with plastic intake manifolds (which flow coolant between the heads to hasten warmup) with differing heat expansion characteristics than the cylinder heads were problematic. The chemistry works if it's handled properly and there are no underlying problems with the cooling system. The Japanese automakers considered that an acceptable risk, and time, so far, sugggests they're right.Īs for the inference that DEX-COOL is inherently problematic, nonsense. GM specifically rejected using phosphate out of concern that if it precipitated out of solution as hard crystal, it could cause waterpump seal damage. The circulating "unused" phosphate is available to quickly repair the OAT protection coating in the event something sloughs some of it off. OAT can take up to 3,000 miles of operation to build up an adequate protection film (though once established is very long lasting unless mechanically disturbed). It has no effect on the generation of cavitation bubbles. Phosphate latches onto aluminum almost immediately. The phosphate content which all three major Japanese automakers specify is for added quick aluminum protection - especially important now that the Japanese "big three" are filling their engine bays with aluminum motors, as well as using aluminum heater cores and radiators. It is silicate-free but contains some phosphate, which provides some protection to the water pump from cavitation damage. Then I will sit back and see if I can convince myself to do the same with the Corolla. But when I started to learn those stories surrounding DexCool and the different ingredients (no silicate but phosphates) in Japanese cars, I feel a little bit uneasy from time to time. I was actually excited about the 5 years/15000 miles claim. I had been using Prestone (conventional green) all my life and Dexcool was the only "Prestone" coolant on the shelf at the time I visited Wal-Mart. I plan to use it on my 2000 Mazda MPV, which is over-due in the coolant department, and my son's 1999 Altima, which I replaced with Prestone DexCool last year. Last week when I found out that a local dealer has the Toyota red at 13.88 coupon price, I went ahead and bought 4 gallons. Since then I learned that the red is similar to HOAT and can last longer. Zerex G-05 was actually on my mind but I could not find it anywhere (Kragen, Autozone, Pepboys) at that time. Back in May I changed my Corolla OEM fill (red) coolant with Prestone "all makes all models" extended-life because I didn't want to pay 17.50/gallon for something that (the guy at the dealer parts counter said) would only last 2 years. Mickey, thanks for confirming that Toyota red is HOAT. I chose not to use the Toyota red because of price and availability. I recently flushed and refilled my wife’s 2002 Camry with the red coolant in it. Apparently the reason is that Honda has taken a public stance against coolants containing 2-EHA (2-ethylhexanoic acid). But they recommend their Zerex G-05, a HOAT, for Honda. Zerex recommends their DexCool clone, Zerex ExtremeLife, for 1997 and up Toyotas. What's going on, here? Prior to 1997 Toyota used a conventional green coolant.įrom 1996 forward they began using a unique OAT coolant which does not use 2-EHA (2-ethylhexanoic acid) which is used in DexCool, the GM version of an OAT, and the European OAT formulae. Just had a service writer tell me there were two different Toyota red coolants, one regular and one long life, red and pink. This may have some true in it because the coolant I drained out of the Corolla seemed to be still clean after 5 years/60000 miles! However recently I have reading people saying that the red coolant is good for 5 years/50000 miles. I ended up replaced it with Prestone "all makes all models" when the guy at the dealer's parts department told me that the red one was only good for 2 years/30000 miles. They did have the red one in concentrated and pre-diluted. But the three Toyota dealers I inqured only had the pink coolant in pre-diluted 50/50. A couple of months back when I changed the coolant in the Corolla (yes, it was over-due), I was thinking of replacing it with the pink one so that I don't have to do it as often. The Highlander owner's manual calls for coolant change at 120 months/120000 miles whereas the Corolla is substantially shorter. Both contain phosphates but they are different. I believe Toyota switched from the red to the pink around 2003. Toyota calls the red coolant "long life" and the pink coolant "super long life". The Corolla came with the red coolant and the Highlander came with the pink coolant. I have a 2000 Toyota Corolla and a 2004 Highlander. ![]()
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