FC giving up the ghost? Loosing coolant.
 

Hi everyone!

This is my 2nd RX7, the first I had when I was just a kid at 19 and didnt know anything. Now in my adult years, I am more serious about owning and maintaining a rotary.

That said, I picked up a S4 N/A that sat in a barn for a year or two. 134k. Drove it 9 hours from Washington state to Utah and other than dripping out the coolant overflow when we first started the trip, the trip was wonderful and temps were great.

Once I got it home I upgraded to a Koyorad (good thing I did, the old radiator was running 1/3rd to its strength cause of an actual birds nest wedged in there).

Now the system is dialed in, 100% air tight. Not a leak to be found. Went over it with 3 mechanics a bunch of times. But Im loosing coolant. After 10-15 or so miles, the beep comes on and I check it and it looses about 8-16oz for those mentioned miles.

I smell coolant, not sure if its from the coolant I sometimes spill when refilling, or from another source.

My mechanic friends say they think its a coolant seal and I would need a new engine and or rebuild. They mumbled something about the old man leaving it in the barn with water in the system instead of 50/50 and that wore down the seals and Im burning the coolant out of my exhaust.

Well, Im definitely aware that I will need to rebuild or get a new engine at some point. But before I go down this expensive road, I just want to make sure we have exhausted all possibilities because the engine itself is running VERY healthy with amazing compression for the age.

The only thing I dont understand is how it made the 9 hour trip with no problems before the radiator swap. Also they say Im burning it out the exhaust, but I see no fumes nor do I smell the coolant at that end. So I figure I would see what you guys think.

Thanks so much for listening, hope your weekend is a good one!

Quick easy thing to do, when its cold take the cap off the thermostat neck and start it and let it idle for a good half hour and watch your coolant, if it starts gushing out, or you see alot of “champagne” bubbles, you have a break in a coolant seal

The engine sitting for a couple years isn’t good whether there was water, or a 50/50 mix in the system, coolant turns into an acid when it gets old and degrades many things

If you do what I suggested and you don’t any bubbles or geysers, the next place to look would be the water pump

I think I got both... not exactly a geyser, but I definitely gushed out half my fluid by 5 min and was showing bubbles.

Check it out:
https://youtu.be/bWisayPDOaU

Ya, you lost a coolant seal, and judging by the color of the coolant, you may have a broken coolant seal bridge due to corrosion

Rebuild time i’m sorry to say

I'm not sure if it's the same as an fd but there's a plastic water fitting on the passenger side that's prone to leaking

I remember hearing that you cant used a pressurized machine to flush the coolant. This was never done, but when the radiator was upgraded, they did use a pressure test. Also, some high end radiator caps (the same used in skylines and STi) were used. Could either of these have blown the seals since the engine was good before all this happened?

I’d go with more crappy luck TBH with you