Es300 Overheating/cooling Maintenance

[Monkeyface]

I have a 1995 ES300 and it has been overheating for the past week. I have owned the car for 2 years and I have never did a radiator flush so that might be the problem but I just wanted to check to make sure if I need to replace my water pump too.

When it overheated I drained and replaced the fluid in the radiator using a 70/30 mixture. I didn't do a flush because I was in a rush. A couple days later all that fluid was gone for some reason. There are no leaks in my radiator and my coolant isnt leaking anywhere. There is a hole in the coolant reserve box but coolant doesnt leak from there.

Is doing a radiator flush good enough?

Should I replace the coolant reserve box (I don't know what its called) if there is a hole on top of it because I may be losing pressure from the hole?

How do I know if I need to replace the water pump? Does there have to be a leak?

[rhkwon]

R U sure you put in enough coolant? I'd recommend a 50/50 split.

[steviej]

After you put in the replacement coolant, did it overheat again?

Have you had the system pressure tested to make sure there are no small leaks.

What was the cause of the original overheating.....bad radiator cap, waterpump going?

The coolant level drop is probably just air bubbles working themselves out from when you added the replacement coolant. Coolant heats up, the bubble comes out, the level goes down. Just add more to the overflow jug and watch the level. If the jug has a hole in it, replace the jug, it ain't there for looks. The jug should have some coolant in it at all times.

my big question.....why a 70/30 mix?

steviej

[SKperformance]

Just a small question ,what colour is your coolant?

[mburnickas]

steviej brought up good points. Yup, I must agree why a 70/30 mix? you are shotting yourself in the foot.

I would not just go by color of a coolant. I know that Lexus uses regular coolant (EG) and a red dye. I went to my local diesel dealer, International, last night and talked to some people that I know from going there so long. EG coolants can be purple, orange, red, yellow, green & I saw pink last night-weird. The same colors for ELC, minus green and yellow. Some have more ash then others and more Chlorides then others.

So, do not just go by color.

[Lexusfreak]

I'd go with a Lexus/Toyota long life coolant (or equivilent). Have your mechanic inspect the cooling system for any leaks & get hin/her to look at the thermostat & rad cap & hoses. Use distilled water as well & do a complete flush. After that is performed, keep your eye on the fluid level for the next week or two in the recovery tank. Top up if needed, but if your adding a lot in that time, take it back because something is wrong.