i have a 2000 durango 5.9 and the coolant reservoir is leaking and i dont have the money to replace it my father inlaw told me as long as the radiator has water in it the reservoir doesnt need to be filled i live in mostly always sunny san diego california the worst it ever got during the summer is 104 it doesnt last long and im not a heavy driver and im rarely in traffic i heard talk about distilled and tap being good and bad on both sides im wondering given the weather conditions and my daily driving is having just water fine for the engine?

 

The res is there to handle pressure expansion overflow, which will leak out from your broken tank, and not be used later as the engine cools. It's $16.64 at Rock Auto.

 

i understand the reservoir is fairly cheap but can the truck radiator run with distilled or tap water given decent weather and driving without issues?

 

the best way to look at this-- is if the tap water you are using is decent for your coolant system. Check the oldest taps or faucets in your home if you see scale and mineral biuld up of sodium, calcium,copper. I never use tap water. Distilled is better than tap water, but deionized is the best all minerals are removed in deinozed. destilled can still have minerals in it. Many will say water is water I always ask if they scale or biuld up on taps then they follow my reasoning.

 

My comment was about... if this is the story for a $16.64 part, you're in deep dodo owning an old vehicle.

I've only used tap water in everything I've owned for 50+ years, and I keep vehicles a long time. I've never had contamination issues.

 

You should only use distilled water in it, same as the battery. Regular tap water has minerals that attack the internals of engines period.

Also you can get the 50/50% antifreeze mix and use it if you would like.