I started as soon as the parts arived. before, my temp would read 3/4 to 4/5 before reaching the High mark. now my needle sits around the 1/5 mark, below what i think is considered normal (1/4 of guage) from what i've searched. should this be a concern? i'm worried i placed the thermostat in wrong and cause overcooling...

Before...


new rad cap and thermostat, all OEM replacement...
and now the results...

After the replacement, i went for a drive and sped through the highway, I pushed it hard from 0-60 and coasted once i reached 100. The needle still reads the same temp. I hope i'm not over-cooled...
Again, should it be at the 1/4th mark? Or is this what I should expect?
Thx, Sodara

 

little low, but a good sign that your cooling system is more than up to the task.

 

I wish mine was that low.....however, it has been doing better after some tweaking and now stays right below the middle.
Nice engine bay by the way. Clean looking car.

 

yeah, thanks. I think I can finally go auto cross, now that my cooling system is functioning again.

 

thats about where mine sat

 

how often should the thermostate be replaced? how can i check it? i did a colant flush but didnt know about the thermostate, can just replace it now or do i have to flush it again? my car does not go over the half mark, its a s5 n/a gxl. thanks

 

You do not need to flush your system again. Just take off the pipe, replace the thermostat, make sure the new one is in the same position, put on a gasket or rtv, and you are good to go. If you have never done it before, I would say do it soon just for safe measure and basic tune up. Its really easy and cheap.

 

apparently, many people say the stock Mazda thermostat and radiator cap is really good already. Mine just recently started overheating so i trouble shoot. after the flush, it still overheated which lead me to the components of the system... fan, radiator, cap, thermostat, and hoses. my odometer now reads 62k miles... since you're wondering when to replace. I think the thermostat should last a long time... And i did a search, s5 is normal when the needle is 1/2. so i think you're still good.

 

when replacing the gasket, what should i use to clean out the old gasket? or should it just seal? will the thermostat at napa auto or kregan work?

 

you can smoke your stock gauge readings..... them are way out from real values.

Get you a quality aftermarket unit with fast response to be safe.

REgards
Iwan

 

My temp gauge started reading lower than it used to despite having a brand new Mazda thermostat. When I installed an aftermarket temp gauge it showed the engine temp to be right where it should be (~85degC/185degF cruising and idling), so I figure it was just the stock gauge showing its age.

 

Yep, or the temp sender all gummed up and dieing.