Jordan, Interested in learning about FC's and how they work
 

Hi, my name is Jordan D. I reside in the great Pacific Northwest. Within the last 2 years I purchased my first car, which happens to be a 1986 13B N/A GXL RX7. I was not too familiar with the rotary engine and its mechanics but was always intrigued about their unique design. When I bought the Rx7, the previous owner was of relatively young age and admitted to blowing all Apex, Coolant Seals. He informed me that the car started and drove but in doing so it billowed out large blue/gray smoke. Previous owner also boasted about getting car up to 120mph on highway with smoke purging. I knew the car would need a "fresh rebuild". I paid a local rotor head for new internal seals and used/salvaged rotors and housings. After installing the fresh motor, I could not get the engine to start for the life of me. Pulled a lower spark plug and it was fouled with coolant and when turning engine over with EGI fuse unplugged, it was apparent there was coolant seeping from the open spark plug socket. Took the engine back to the mechanic and he inspected the housings and noticed he overlooked a small electrolysis hole in the housing causing the plug to foul. He then replaced the housing and used a new rebuild seal kit. After getting this fresh rebuild installed for the second time, the engine would crank but not fire and run on its own power. We hooked the car up to a tow strap and after towing the car a few feet and popping the clutch the Rx7 roared to life letting out large smoke clouds from exhaust ( I forgot to mention before attempting to pop the clutch we squirted a small amount of oil into the spark plug sockets ). Ever since then I have been reading forums and trying to understand how my FC is suppose to properly perform/operate. I still have minor issues with the ride but nothing that will keep me from getting from Point A to Point B. I love this car and can't help but grin when romping this beauty, I know she is rough around the edges but her attitude makes her one of her own and mine and there are not too many other Rx7's around where I live. She definitely likes to test my patience and try to give me headaches but I love being behind the wheel and intend to never give her up, Life Long Project :). Well this is my introduction and I hope to learn a lot from everyone on this site and hopefully fulfill my goal to become familiar and knowledgeable about these awesome cars. Thank you for taking the time to get to know me and my Rx7 :)

Obviously, the PO didn't know how to treat a rotary. They love to rev. They run great at high rpm's. My 91 NA has seen 8700 RPM and didnt miss a beat. FYI: it sounds like the PO ran the car hard while cold. That is the easiest way to blow coolant seals. Make sure you baby your 13b until it's up to full operating temperature and she'll last a good long while. Mine's still running the original engine with 85k miles and as long as my electrical gremlins havent drained my battery overnight she'll start every time. I even had a bad secondary injector that was stuck wide open flooding my back rotor and the car would still start idle and run without dying. These engines are resilient if treated properly https://www.rx7club.com/images/smilies/icon_tup.gif

Unfortunately I think my coolant seals have gone south :(. Every morning since the rebuild, I would start the car there would be white smoke for a few minutes then it would slowly go away but my coolant levels would always be okay, but now my coolant likes to stay in my overflow tank and occasionally my add coolant buzzer likes to scream at me.. :(

That's definitely not a good sign. How many miles are on the rebuild and how have you been treating it? Does it smell like its eating coolant?

I am having similar problems with my 86 rx7 nonturbo. i bought the car with a bad motor. but i had a good replacement to put in. i didnt have trouble until i started to connect the wires on the passengerside of the engine compartment. now i have 2 brown/black wires that dont match the harness on the motor. every other wire had a match except thess 2. but at the same time i have 2 black wires on the motor harness that dont match the wires coming from the fire wall. so now i have 2 wires from the firewall and 2 from the motor that dont match. if you haveany advice i would appreciate the knowledge.

There are 8,000 miles on the rebuild and I treat it fairly well. I let it warm up until the engine temp gauge gets above cold before driving it but if I'm in a hurry in the morning and cant sit around for it to warm up, I never take the rpm's above 2800 in each gear until it reaches operating temperature. Also, when I drive it I make sure to get high in the rpm's at least once before arriving to where I need to be and shutting it off, I heard it's good for the engine and stops carbon buildup. The other day I was driving to work and came to a stop light and smelled like coolant and then the buzzer came on. I fixed a hose clamp that wasnt properly seated and havent smelled coolant or heard the buzzer come on again but the coolant still likes to hang out in the overflow tank. Ever since the first time I heard the buzzer I have been making sure not to drive the car every day, just in case.

As far as the wiring question goes, sorry I have no idea. I just finally tracked down my electrical issues today. Turned out I had a bunch of random symptoms due to my windshield leaking and getting my cpu wet. I can't believe the car even ran there was so much corrosion. I believe i have some wiring diagrams somewhere I'll check in a little bit when i have more free time.

Jordan, I saw a page somewhere on how to check for bad coolant seals when i was shopping for my FC. IIRC it said start the car cold, remove radiator cap (or resevior cap I forget which I havent looked at my cooling system to see if its sealed or not. I believe it isnt so the rad cap would be the dead giveaway) and watch to make sure you dont see any bubbles. I'll search for that link in a little as well. The white smoke on startup could be any number of things. Sometimes (especially when it hasnt be run for a few days) mine blows out some oil smoke on startup. The clamp you mentioned could have been leaking this entire time without you knowing it. With only 8k on it I couldn't imagine the engine being blown. It is better to let the car at least hit normal temp on the gauge before driving and i tend to take mine very light throttle to 3k-3500 when its not quite fully warmed up. I believe thats all i can offer right now feel free to correct me on anything wrong or ask if anything is confusing.

Thank you for taking the time to help me try and understand what I may be dealing with, it is much appreciated! I will run a few tests today to see if anything pops up and I will post an update. Yesterday I pressurized the cooling system and it held pressure just fine.

Do you think maybe a bad thermostat or water pump would cause the same thing? I used aftermarket parts and not OEM Mazda parts

thanks
 

thanks again for the advice.

bad water pump would only leak..especially if you say you replaced it..so NO on that.
Thermostat could be..Mazda thermostat only..Stant brand etc are crap.
Have you tried another NEW rad cap yet? a Faulty cap can depressurize the system and then not let the coolant return to the engine when it cools.
Also a bad hose to the reservoir or INSIDE the reservoir will prevent the coolant from going back after it has entered the coolant reservoir.

Thank you misterstyx. I called the local Mazda dealer and they ordered me a thermostat (only $20 so not too bad of a part to just throw at it) and they also had a filler neck cap in stock that I am going to pick up this evening.

Here are the diagrams I found when I was dealing with my electricals:
https://docs.google.com/file/d/0Bzy-cXUDftdrYWExNjAxN2MtZTBiNC00MTVlLWIzMTctZTliZjA5OT QxNTE1/preview?pli=1&hl=en_US

https://docs.google.com/file/d/0Bzy-cXUDftdrMDM3ZDI0MGEtZWJmNS00Yjg1LWI0MzMtYjFjMGU2OT UwMDc0/preview?pli=1&hl=en_US

https://docs.google.com/file/d/0Bzy-cXUDftdrMmFmNzY3MmQtNWRhNy00YWU1LTgyMzAtZDMxMGFmNm ViMjZj/preview?pli=1&hl=en_US

Hope they can help

Guys,I am seeing 2 different members posting here.
If you care to ask a question and are NOT the OP then please do.(86Gen2Dream)
It's not really respectful to overtake another one's thread when they have taken the time to submit the question.
They need Their answer,that is why they posted.Not answers to someone else's problem.
It defeats the purpose..sort of like advertising a whopper at Wendy's..not cool.Get your own sandwich..chuckle!
OK Gentlemen?
THANKS.

Sorry, I forgot that was a rule here. I'm used to other forums where threadjacking is super common and was just trying to help. I just signed up yesterday cut me some slack haha. Anyways, Jordan update us on any tests you may do.

I apologize for that i just got on today. i meant no disrespect on your thread jordan.

Its okay guys but I have an update on my rx7. I pulled my EGI Fuse and cranked the engine with full throttle and I have a video with the results. Tell me what you think....

That definitely doesn't look good to me :( I've never blown an engine in any of the cars I've owned in my life so idk the symptoms but bubbles in the coolant while cranking seems really bad to me...

It is possible that any of the above mentioned possibilities could have happened, air ended up in the cooling system, and it overheated blowing the seals. Or in a very optimistic view maybe thats the air coming out of the cooling system (very unlikely imo but maybe possible idk lol just throwing it out there)

Wait...did you bleed the system after you fixed the clamp that was causing the leak? That video could have indeed been you bleeding it if that had been your issue the entire time (hoping for your sake)

I have not bled the system. I was thinking maybe I should do that but the heater always blows warm. I will look up how to bleed the cooling system and attempt to do that tomorrow before the weekend. Hopefully there is just a pocket of air somewhere causing this no return of coolant from overflow tank. I even pulled the EGI Comp fuse and cranked just for a second before this test and then pulled the spark plugs and they were dry.

That's actually good news. I think this problematic clamp may have caused some air to enter the system. It took months bleeding the cooling system on a 331 rattruck/streetrod build me and my bro have going on... but we only ran it about once a week because we had other issues going on with it.

You are awesome! Just when I was about to condemn my seals you gave me a little bit of hope. I would have never thought some air bubbles in the system would cause my car to start acting so strangely. I will do some research tonight, learn how to bleed the cooling system and then hopefully drive the car home with no buzzer or lights flashing at me and report status back. I really do appreciate all the help you and everyone has been offering me. There are not too many rotary people around where I live, well that I am aware of, so its been tough treading with this project.

OKay Okay sooooo... I pulled my filler neck cap (topped off coolant), unscrewed my radiator bleeder screw and then started the rx7 and turned heater on full blast. Bubbles rose then the cooolant level dropped and then after about a minute coolant started leaking consistently from bleeder and then I closed bleeder screw and topped off coolant and then went for a drive after letting the rx7 warm up for 15minutes. After getting back from the drive I checked the overflow tank and coolant did not go into the tank (Bad or good?). I then shut off the car and added coolant to the overflow tank so that when it was cooling down it had coolant to draw from. I also noticed that when I was driving the rx7, my gears had more pull to them.. Could an air bubble in the cooling system have robbed the car of power? Hopefully my coolant problems never come back and I can sleep in peace now haha.

Typically the thermostat is a high point in the system (anyone feel free to correct me on this im used to old carb'd v8 cooling systems cuz my family was old school about cars when i grew up). If an air bubble gets trapped at the thermostat it would cause a false temperature reading making the car think it was cooler than it is and would cause the ecu to run the mixture much more rich than it should be at full operating temp. As far as the overflow not filling, if you filled the rad with the car warm i could imagine the coolant didnt expand enough to fill it. Your last post sounds like good news just keep an eye on it and if i were you (im a little ocd lol) i would probably repeat the bleeding process another 2-3 times just to be sure there is absolutely no air in the system. Glad your problem was something simple.

I will repeat it just to be safe. Hopefully that was it