My 1988 RX-7 convertible runs fine, with only 25,000 original miles; I have owned it for three years, and living in CT, worry about the cold temperatures. I had cooling system fluid tested by local Mazda dealer, and he said fluid shows no rust or crud, but it appears that fluid has been topped off many times with no effort to maintain 50/50 mix, and highly suggested pressure flushing system and replacing fluid. I have scheduled to do this, but am a little worried about causing more harm than good. Any suggestions?

 

Flushing the system is certainly a good thing to do and will not cause harm. In that colder weather in CT, you really want to maintain the 50/50 mix as much as possible.

Don't worry man, you're doing what is best for your car.

 

If it has a problem, it's better to have it show during a test that on the road.

The additive package in coolant pretty much wears out after a year anyway.

 

Get rid of the POS stocker and get at least an upgrade all-aluminum unit.

This is the reason why...plastic endtanks.
They can crack and fail without warning sometimes.
It only takes a small rock or an errant hand leaning on it too much, and it's not repairable.
At least an all-aluminum unit is more robust and gives you better cooling capacity.
You win on both counts.


-Ted

 

Hell, even Modine makes an all brass replacement.. Not aluminum, but they dont have plastic endanks.

 

I'll vouchfor this, my top endtake exploaded on the way home once.
Of course, there was a small crack that i had sealed with a few layers of epoxy.

 

I had the plastic top tank split.
I patched it with Bondo Marine Epoxy putty.
It was still holding when the solid brass replacement arrived.

 

I heard the brass (or was it copper?) replacements caused corrosion from dissimilar metals. Just looking to verify.

Ditto, but mine exploded violently after a while.

 

Be VERY careful removing ANY bolts. I broke 3. (1 coolant cap bolt, 1 coolant overflow tank bolt, and 1 water pump housing bolt) All I needed to do was replace a hose, but since it was out of commission I decided to pry around and brake ****. Now I can't drive my car.