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Preventive maintenance or overdone: Thermostat on Acura

1999 Integra with 90k - this is my primary car too but not used to commute. Have a 2nd car too.

The radiator upper hose seeps a bit - loosing 1qt in a year.
When I fix this, should I also do the lower hose? If I am doing the lower hose, should I also do the thermostat?

Had the timing belt, waterpump about a year ago - had I known, these, I would done then too.

I am also concerned that the newer OEM thermostat might have poor life span than the one in the car - apparently from 1999 - I bought it in 2004 when it was a lease return. I have another 25 yr old integra and I never had to do the radiator hoses or thermostat. Also, this 1999 integra has a newer radiator but the other integra is still on the original radiator. OEMs are probably being made in China - besides newer radiators are plastic.

If it is just the upper hose, I can easily do it myself. If I were to do the rest, it is a bit intimidating and possibly run into newer problems … leaks developing etc. This is what I am wondering what is the best strategy?

Ideally You Should Replace The Thermostat And Lower Hose While You’re Working On The Cooling System.

Under the circumstances (recent coolant change with pump & skill level challenge) you should be able to just wrestle the upper hose in there. Do the thermo and hose when it’s time for new coolant in 2 years.

Be sure to properly fill and purge air from the cooling system in accordance with car manufacturer’s procedures for your make and model. Recheck coolant level and add if necessary after the first couple of engine heated/cooled cycles.


I Took A Look At The Thermostat Housing Location On This Car. It Looks Like It’s Pretty Straight Forward, But If You’re Not Confident Then Don’t DIY Unless Somebody Who Has Done One Can Help.

Using a new thermotat seal and locating the thermostat air-bleed to the top are two areas of concern.

You may want to check with a local independent mechanic. Replacing that lower hose and thermostat may not be very expensive, labor-wise, on this car.


Back when I drove (three Hondas) every day I changed the thermostat every 4 years, every other coolant change.

As a preventive measure, I used to change out all the hoses and thermostat every two years or 50,000. As long as you’ve got it all open and the coolant drained, its not that much more to do the rest of it. But I’m a preventive maintenance and repair person and hate unforseen problems. I just changed out my 5 year old battery because it was simply 5 years old.

If your DIY, a thermostat is very cheap insurance. I change out the thermostat and rad cap every coolant change. My truck uses long-life fluid, so I change every 4 years. If the upper hose is showing weakness, I guaranty the other hoses, even heater hoses, are also weak. Changing them out now with all the coolant out will save you from that dreaded late-night-on-a-Sunday-night-in-the-middle-of-nowhere-with-no-bars-on-the-cellphone situations when one of those ancient hoses blows.