Amir Sarabi

Hey guys. I've got a 91 fc turbo and I d had some problems but right now I'm asking that I have a coolant problem. So I topped off the radiator and the reservoir and started her after deflooding it. I started it maybe three times that day and the last time it ran about 20 minutes while me revving it a little bit. Turned the car off and saw that the reservoir was completely full and the steam from the hose was making it bubble and after it sitting for a bit the reservoir went back down and everything looked normal. I just wanted to get some opinions on what could happen and what I could do to check on what's going on. Thanks guy!

DC5Daniel

iTrader: (10)

First, there have been several revisions of the FC cooling system, it may be helpful to get some pictures of how yours is setup (different cap combinations, different overflow reservoirs, difference vent hose locations, etc.).

Your system is boiling over, which usually means either you have a bad radiator cap, or a leak somewhere in the system. Chances are someone in the last 30 years has replaced your radiator cap with some cheap parts store version; you're going to want to get an OEM cap. You can also rent for free a coolant system pressure tester from any auto parts store.

I should also point out it's not uncommon to hear some boiling from the engine after shutdown. There is no coolant circulating and localized hot spots can form. Boiling in the overflow is however, abnormal, and a properly functioning pressure cap will vent to the overflow before boiling point is reached.

Did you burp the system? Are you using a coolant/water mixture as opposed to something silly like straight water?

Amir Sarabi

For sure I'll definitely do that it just boggles me cause the car ran great when I first got it and now it's just one thing after another. I'll get some pictures for ya TMR hopefully. It's an turbo conversion from an NA so it's a fully built engine with a greddy intercooler system and a shoot I don't remember what radiator it's got but I'll get some pictures for ya cause I'm new to this whole thing so I need some help. Thanks for the super quick response tho.

DC5Daniel

iTrader: (10)

Welcome to 30 year old cars, especially an RX7 . This will become a common theme until you go through everything on the car, don't kid yourself.

If it truly was fine and this popped up unprovoked, chances are you just need $30 worth of new radiator cap from the dealer and you'll be on the road again.