rsteensland

Hey guys, new member here. And new to Rx7's in general. Though I've been doing plenty of research before I purchased my car. I'm pretty sure I have a small hole in one of the coolant seals, but before I pull it for a rebuild, I could use a few more opinions to confirm my suspicions.

It's a 94 rx7, running non-sequential converted stock twins, apexi power fc, and air to water IC, if any of that helps with diagnosis lol.

Anyway, it literally never overheats, runs perfectly normal temps. But it blows coolant out of the reservoir whenever I drive. Even with a cold motor and just starting and idling for a little bit, it will pressurize the coolant system.

I just put a coolant funnel on and let it idle for about an hour. it stayed at 160 deg the whole time with fans on and bubbled the entire time.
I would consider that a done deal, but if any of you watched the gears and gasoline RX7 trip across the states. The same thing happens with him, and it took over an hour of bubbling before he got all the air out of the system and turned out to be fine.
I just want to make sure I don't pull the motor for no reason.

Do any of you guys have any other tests or ways to more effectively bleed the system?

Here is a video of the coolant bubbles at the end of the hour. The end of the video has a close-up side view of the bubbles.


Thanks so much!

DaleClark

iTrader: (55)

Welcome!

You should get one of the kits that tests for exhaust gasses in the coolant to be 100% sure. Most likely you have a bad seal but this will give you the certain answer.

It looks like some things in the car will need a go-through - that vacuum cap with a hardware store hose clamp on the nipple that used to go to the AST is a recipe for disaster. Most likely there's other janky work like that that probably caused the problem in the first place.

You can drive the car but it's on a clock, it's not going to get better. Start planning on a rebuild.

Dale

rsteensland

Thank you! That's a good idea, I had been debating trying to find one of those kits.

But yeah, I figured it'll be a good time to pull everything and clean up any wonky things from previous owners. I def am planning a rebuild soon. I just wanted to be sure.

DaleClark

iTrader: (55)

I've seen those kits at parts stores, it has a fluid that you let the bubbles vent through, if it changes color you have exhaust gasses in the coolant.

Dale

Sgtblue

iTrader: (16)

As steady as those bubbles are coming out...and blowing the coolant out the reservoir, I’d be convinced it’s a coolant seal failure. But testing won’t hurt if you don’t want to wait too long. Coolant sitting in the seal grooves can cause pitting and erosion, which will make the iron unusable.