What is the proper coolant for a WJ 2003 4.7 V8? Haynes says HOAT 5 year 100,000 mile. I already knew this but I thought all HOAT was red? I'm having trouble finding the Red HOAT. Oreily has HOAT coolant but it's yellow. I'm doing a coolant flush and wondering if that yellow HOAT would be good for my vehicle? Thanx.

 

HOAT coolant is a low silicate solution to help prevent corrosion in systems with aluminum components. Regardless of color, if it says HOAT, it's compatible. If you're doing a complete system flush including the block, you can use ANY antifreeze coolant and be fine. We've used Green glycol in aluminum engines for decades and had no problems as long as it's changed regularly. HOAT says it's good for 5 years or 100,000 miles, but I wouldn't leave anything in my engine that long anyway. JMHO.

If you're buying full strength coolant, use distilled or demineralized water with it.

 

Thanks for the info!