Hi everyone,
Hope you RX-7 Guru's can aid me. I just got an RX-7 about 2 days ago and it is overheating. Whenever i drive it for more than 3-5 miles the temp skyrockets and the coolant light goes on. Then when i pull over coolant is coming out to the overfill tube off the container. Then i can hear a bubling sound it seems. Im not quite sure how to remedy this so if you guys could put in your 2 cents that would b great,
Many thanks

Nick

 

#1 don't drive it till you fix it. rotaries + heat = bad

#2

https://www.rx7club.com/2nd-gen-archive-72/%2A%2Ahelp%2A%2A86-base-overflow-bottle-filling-all-time-19294/

 

It seems to run perfectly fine at idle, but when i rev it up (in my drive-way) the add coolant went on but temps stayed the same. i seriously hope my only option is a rebuild, i just dont have the resourses. Is it easy to rebuild a rotary? how long might it take.

 

Well, first i'd check the coolant overflow reservoir, see where its at. if its low, add more. then try adding some at the actual coolant cap.

 

Was the coolant/radiator flushed recently? If the coolant was replaced recently it is possible that an air pocket is causing your trouble. Just warm up normally with your air bleed and filler cap off until the thermostat opens. Remeber to turn heater on to high once warmed up also because the core might hold air that gets reintroduced into the system if it is an air pocket. Might see bubbling for a while but not get overflow then refill with coolant slowly with engine running then close air bleed and cap.
If the bubbling doesn't stop or if coolant shoots out of the filler then you might have a leaking coolant seal and you would more than likely smell exhaust in your coolant. Bad news, You'll be needing a rebuild then.
Hope it's just an air pocket and you can "burp" your system. Good luck.

 

ouch...i think your coolant seal is gone......
did seller mention this problem??

 

I got it at an auction for about a grand so didn't really get to talk to the owner, thing is that the car was driven on accident without a radiator cap, ouch, but was immediatly pulled over and i added collant and continued on my way home, since then i havent been able to drive it more than 5 miles. How difficult is it to rebuild? What's the time scale for an overhaul? Oh and where exaclty is the air bleed?

 

they have videos on the rebuild that can help.....

 

wait, i know this is stupid but check the the hoses behind the TB, you said it was spewing coolent? That happend to me and it was the Rear TB to Rear Housing coolent Hose... Hope this helps i dont think that a coolent seal would "spew" coolent everywhere

 

true, but if its coming from the overflow tank then....
chances arent good

 

what about the water pump when my alternator belt snapped wich also runs the off the water pump all my warning lights came on and it started over heating fast

 

It is definitly coming just from the overfill tank. The thing is i ran it for about 10 minutes then let it sit overnight, then the next morning slowly opened radiator and coolant went into the overfill then air. I might just take it to the dealer cuz i dont know of any rotary shops near me in Milwaukee, wi. But this is the only problem with the car and got it for a grand at the auto auction. It starts a little rought cold, but then it purs.... until i drive it ha. Would a little Bar's leak or block weld solve the problem for about 10k miles?

 

DONT TAKE IT TO THE DEALER, unless they actually KNOW rotaries they will just screw ur car up.they know less about the rotary engine than u probably do.

 

before adding coolant start car and turn on the heater full blast and then open the radiator cap you then should see air bubbles and then start adding coolant

 

You mean the STEALERSHIP

 

this has had succsess for some people but didnt work for others...if its to far damaged (coolant seal) it may be to late....

 

Quote: "Oh and where exaclty is the air bleed?"
I dont know if the S5's had one on the radiator or not. S4's have one near where the hose from the water pump goes into the radiator on top. It's a plastic, phillips screw head looking thingy. You might not have one on yours though. Even without one you should be able to bleed the air out just by leaving the filler cap off and running the car at a fast idle until it warms up and opens the thermostat. Remember to turn on your heater then and check to see if bubbles come out.
Might want to replace your radiator cap if it's old too. Might not be holding pressure properly and cause the overflow. Could be something as simple as that.

Are you blowing white smoke out the tailpipe? I'm not sure if the RX's do that with blown coolant seal. I'm guessing that might depend on whether the seal blew on the intake section of the housing and not the compression/ignition/exhaust side of the housing which is more likely but it might do that also if water enters there when the cooling system is pressurized still after you shut off the engine. But then you also get the constant bubbling and gas/exhaust smelling coolant if you did I would think.

Good luck.

 

could be a faulty thermostat or a coolant seal, i would opt to actually check the car before thinking the motor is gone out. you will find that a lot of people around here will just tell you to rebuild the motor, rather do a coolant seal test listed in the FAQ or pull out and test the thermostat and bleed the cooling system properly and test the system for leaks before assuming it needs a rebuild.

 

One thing I'd check is the radiator cap. I've seen these fail and cause problems that you speak of. If nothing else it's cheap and easy to address.

 

Yea i got a new radiator cap already, and I talked with the owner and he said the thermostat was recently replaced. So the mazda dealership wouldn't know how to fix a rotary? i think i will start by draining the system, filling it up with some bars leak and let it run for a while, so i can monitor temps. The car only has 100,000 miles on it so i dont know how bad the seal could be yet. I just want it to last summer til i can rebuild it. One thing i noticed is that even after sitting overnight the system is still pressurized, i dont know whether it is normal or not. I hope some bars leak will fix it. Other than this there is nothing leaking externally. Thanks for the tips, hope i can get this to work cuz its one sweet car.

 

are the plugs wet ?? with antifreeze??

 

Don't count on it. The second you opened your hood you knew more than most any of the techs they had would know...and even if they thought they knew about rotaries via the Renesis...the Wankel is a whole different ballgame.

 

so basically im having a guy come over to pressure test the system. If it fails, the engine is hot and needs to be rebuilt, right? If it passes, its probably the TS or WP. Which would be very good news. Another thing i forgot to mention was when it does over heat it will come back down to mormal and run within a few minutes. Its very wierd, i just hope the engine isnt shot, cuz then i basically have to sell it. Thanks for your guys' input

 

I had this same problem, STOP DRIVING IT NOW. I needed a new front plate and 2 new rotor housings! I bought 2 videos online, the diy 13bre video and the atkins rotary video. Goodluck with your rebuild.

Go read as much as you can in the archive about stuff, it will be a big help in the end

 

well yea it has just been chillin in my garage since i noticed it. How long did it take you to fix it??