lcdial

iTrader: (1)

I'm a new FD owner -- 1993 VR with all the reliability upgrades -- but reading these forums, I can't help but be a bit paranoid about its reliability. Searching on these forums has been tremendously educational, but at the same time, it's somewhat like asking a hypochondriac to go to med school. I'm hoping this group could help alleviate some of my concerns -- or at least focus me on the ones that are important. Here goes:

1) Cold starts are bad -- Could lead to flooding: I've read lots of articles about NEVER stopping a rotary until it's had a chance to warm up. I get that, but is this concern overblown? I mean, I find it hard to believe that Mazda could bring a car to the mass market that couldn't make a 5 minute trip down the road without flooding. That said, I'm always super careful not to use my FD for short trips -- Paranoia or Reality?

2) Hot starts are bad -- Rotaries can have challenges starting when warm. I've understood this may only be a problem when compression is low, but it still worries me a bit. The other day, I stalled when parking the car and immediately panicked that she wouldn't start up. She did just fine, but I still worry -- Is this a justifiable concern?

3) Never let the FD run hot -- I know this one is true, and I've got a digital temperature gauge on the A pillar. I watch that thing like a hawk. So much so that it actually takes the fun out of driving. My car runs between 180-200F on short trips, with temps running up to 212F on longer trips (with the A/C on -- once the A/C goes off, she'll settle back down to 195ish). Where do I need to be worried about temps? Is this something I should be staring at every 30 seconds when driving? How much obsession with temps is warranted?

4) Don't run the FD (hard) when cold -- I use the FD as my occasional commuter, which means I will get going when the temps are still cold. I take pains to keep the boost off (shifting at 2.5-3k) until it hits the magic 180F, but how serious is this? Is it okay to start playing with the car at 160F? What harm am I protecting -- different expansion rates on the rotors vs. housings?


Are there any other areas that I should be paranoid about? Any areas of seemingly common issues that are overblown?


Thanks so much for all your help -- on these questions and the massive amount I've learned about my car just following along your adventures...

MattGold

iTrader: (107)

Yeah. Much more reliable when you just park it and look at it.

The truth is: FD3S are finicky. However, you can mitigate a lot of it. Of your posted concerns #4 is just good habit for any car. However, #3 is the most critical. Overheating a FD makes it a ticking time bomb. In most piston cars, you overheat it, maybe you need to replace a headgasket and you're good. However on an FD (or any rotary for that matter) the coolant seals most likely are now toast and you're going to be in for a rebuild soon enough.

#1 and #2 are more symptomatic on cars with pre-existing issues IMO. However, there is some credence to #1. Always better to get it up to operating temp to avoid flooding.

The other thing you really need to respect is Air/Fuel Ratio. I'm sure you've read this already, but it bears repeating; you can't just start throwing parts on a car without a tuner that knows what he's doing remapping your ECU. No full exhausts until you have an ECU and Fuel Pump.

If you roll through all the reliability mods and keep it stock-ish power levels, it'll treat you well.

TomU

iTrader: (11)

IMO, a stock FD driven as it's intended (street) is very reliable.

What "reliability" mods has been made to your car? Some are less reliable than others.

1) Think this is more an issue with previous gens, but it's generally better to wait until the engine warms up a bit before you shut it down.

2) Low compression motors or modified motors may have trouble starting hot. Problem is when you crank it too much and it's not starting, it will flood. If you have good compression, I would not worry about this (if you do worry, let it cool down before re-starting)

3) This is the Achilles heel of the FD. Hopefully your reliability mods have addressed this (aluminum radiator, downpipe, and possibly a second oil cooler and larger intercooler)

4) This goes for most engines, but especially for rotaries.

Are there any other areas that I should be paranoid about?

If the vacuum hoses are original, they (and your solenoids) may be at the end of their life. This goes for all rubber in the engine compartment. Suspension is probably at it's end too.

Natey

iTrader: (19)

Never had a hot or cold start issue in any of the 3 engines I've been through since I bought my FD.

See? They're reliable as ****.

knotsonice

iTrader: (2)

If you can list what was done to the car. Just saying all reliability mods could be anything. One thing I have noticed with cold starts during the winter can be a pain but that was self inflicted on myself using 20/50 oil. Since then I'm using 10/30 during the winter and 20/50 spring/summer. I've had my FD for close to 17 years now (my stock turbos had 178k miles on them the same time the Rotary went, this was about 3 years ago and had a lot of work done. I bought the car when it was re-built at75k.) The first 12-13 years pretty much stock few mods: N-flow racing rad, Larger stock mount int, down pipe, high flow cat. Never had much of any issues. I'm now running a rebuilt motor, single turbo and all the goodies under on her some listed below in my sig. And Yes I daily drive her still! As long as you take care of the car it'll treat you right. Keep up on the maint for her!

lcdial

iTrader: (1)

So, my car has a older but rebuilt engine (although I don't have the paperwork on it) and the following:

• custom tuned pfc
• Larger stock mount intercooler
• Racing Beat dual tip exhaust
• Aluminum radiator and AST and
• Silicone vacuum hoses

It's great to hear from those of you who have had no problems! There's some significant selection bias in forums posts. No one generally posts to say that everything is fine!!

Anyone have any thoughts on the desired temp question? I almost wish I didn't have the digital gauge, because I get to wrapped up in it!

knotsonice

iTrader: (2)

If you don't have dual oil coolers I would do that. It does provide some cooling. You may see your temps come down some more. i remember a post from a while back that had all the cooling readings. I think your temps for a pretty much stock system is fine. I'll see if I can frin the post and link it here. I have dual oil coolers (stock) and the koyo N-flow racing rad. On the highway my temps are about 178f ish I rarely get to 185 even driving in traffic.

TomU

iTrader: (11)

Rotary Tech Tips: Water Cooling

https://www.rx7club.com/3rd-generati...thread-571088/

Zepticon

iTrader: (1)

The car: 94 EU mod with stock engine except for HKS downpipe.

1) Cold starts are bad -- Could lead to flooding: Read about it but never experienced it myself. Have taken mine from the garage, driven two minutes to the supermarket, shut her down and shopped some stuff, then started her up and gone to the garage. Never experienced flooding on mine.

2) Hot starts are bad -- Rotaries can have challenges starting when warm. Experienced this a two times. BUt i have always gotten it to start on the 2nd try. Just stopped cranking, and then tried again after 5 seconds and she fired right up.

3) Never let the FD run hot True. Get a bigger radiator, two oil coolers, and be aware when driving in hot weather and slow traffic.

4) Don't run the FD (hard) when cold Goes for every car.

knotsonice

iTrader: (2)

Tom Got it. From 2nd link.

7. Optimum Temps
65C (150F): too cold. According to service manual, EGR valve is non-operational below 150F, "to improve drivability when cold."
82C (180F): getting warm. Thermostat begins to open, circulating coolant through the radiator. Some coolant is still bypassing the radiator.
95C (203F): fully warm. Thermostat is fully open, not bypassing the radiator at all.
100C (212F): boiling point of pure water at atmospheric pressure.
105C (221F): getting hot. Stock ECU will activate fans to cool the car down. Fan speed will be low, or medium (if A/C is already on).
108C (226F): hot. Stock 93-95 coolant thermoswitch activates, changing fan speeds from low>> medium (or med>>high if A/C is already on) (switching to an FC thermoswitch will change this temp to 203F)
115C (240F): getting dangerous. OEM temp gauge begins to rise.
117C (243F): dangerous. boiling point of pure water with 13psi pressure cap.
121C (250F): too hot. OEM temp gauge will point to white line. Boiling point of pure water with 16psi pressure cap.
124C (256F): way too hot. Boiling point of pure water with 19psi pressure cap. Boiling point of 50/50 coolant mix with 13psi pressure cap.
127C (260F): way too hot. OEM temp gauge will point to red line.

bajaman

Too many people think these cars are fragile or finicky, almost like you roll the die every time you get in it. Far from the truth. Most of these cars have run well over 100,000 miles on the original engine, and often through several owners of varying experience. Once these cars have found a new owner who has done the sensible things, i.e. "reliability mods" and rebuilt the engine, you can easily expect to get another 100,000 miles or more with little to no drama.
It's a car, drive it.

$lacker

iTrader: (9)

The best thing for reliability is to beat the **** out of it while driving it
Take it to red line every time you have it out - don't let carbon accumulate on the rotor faces or around your seals

OG BBF

Just want to throw my 2c in. There's a lot of horror stories regarding this topic but the only way you can decide whether it's true or not is to own one, look after it and then make a decision.

ive have 3 FDs and I want to talk about my second one for this topic. I rebuilt it when purchased and we start the story 20,000miles later. I went through a period in my life where things were hectic. My girlfriend was pregnant with our daughter, at that point we didn't live together. On top of all that my father was in and out of hospital, he wasn't well at all. Phone call after phone call I had to be somewhere...hospital....girlfriends, pick up stuff from store, take pets to vet as no one else was able and let me tell you that FD sadly was treated like a cheap *****. Driven when cold because I'd have to rush to thit hospital, shut off when cold, restarted cold....waited hours in traffic during summer temps. The car beeded a tune.....cruising AFRs would his 16-17!!! Foot down, crazy rich at 10.....but I had no chance to map it as I had other priorities....no daily driver. Anyway all I'm saying that FD was abused....everything a rotary needs was not given.....it killed me doing it but I had no choice. But let me tell you, that thing kept on going....during what was probably the hardest time in my life....that FD never let me down, was always there when I needed her.

After when my daughter was born, dad was better and life returned back to normal.....I remember the first day I had to myself.....I gave the car a thorough once over.....the only battle scar it had? Slight weeping from the sump. Compression was still in the low 8s all around, injectors spraying as they should I was shocked.

Now this isn't to say a rotary with maybe 50-60-70k on the engin could handle the same sort of abuse, but I hope his gives you some perspective into my experience with their reliability.

My advice is check compression.....if it's low or the numbers seem weak,build a strong engine. Then look after it. Don't be scared of them....they aren't as fragile as people make out. O ring tech has come a long way from the factory ones, viton is stronger and more resilient. As I always say, if a rotary is unteliable and weak, then it wouldn't have won Le Mans....24hrs being pushed to the limits with crazy temps....think about it

adam c

iTrader: (2)

Its good to be a little paranoid about these cars. That means you will likely respect and take care of them.

I bought my first RX7 in 82. It was a brand new GSL. In 35 years of owning RX7s, I have only been stranded twice. Once was running out of gas. The other was flooding at 8000 ft elevation. My friend blew 2 apex seals on his FD, and we were still able to drive it 140 miles to get home.

Reliable but finicky (as mentioned above) is a good description

arghx

iTrader: (3)

Original coolant hoses and radiator will fail on you. dual oil coolers help.

Who tuned your pfc? Was it a trusted professional?

Natey

iTrader: (19)

Haha, the old saying went: RX-7, the only car that can go 100MPH with a blown engine!

Montego

iTrader: (1)

If you are near stock levels or not messing with fuel upgrades, cold starts and hot starts are a non-issue. For the most part people who have these issues you will find that they have upgraded injectors, fuel rails, ect... In other words, it is self induced. Myself included as I never had an issue prior to me ******* with the fuel delivery.

Not allowing to run hot can be said for all engines, not just rotaries. You said you have a PFC right? Set the fans to kick in at +85C (185F) and problem solved. Mine stays rock solid at +85C on average and mild spirited driving no matter the distance. It is only on very hot weather 100F that my temps climb, not too bad overall as the most I've seen has been 103C (217F) but that day was very hot and IIRC it was like 105F day!

Yes don't run it hard when its cold. Dude come on- it takes like five minutes and less than a mile of regular driving to get the car up to +80C. JUst practice a little bit of self control.


The only one I can think of (and it is not paranoia)- is the practice of not runing your car hard for 5 minutes prior to arriving to your destination. Because letting off the boost allows the turbos too cool so when you shut down they don't cook. This is a very common phenomenom that applies to ALL turbo cars, not kjust rotaries. Hence the turbo timer market (but don't get one).


Yes the whole rotary is made out of paper misconception... These cars are not unreliable if you leave them alone. It's the owners that have given them a bad rap by cheaping out on components and/or being greedy with their power goals. The fact is that a near stock FD will start every time, won't leave you stranded, and you can pretty much WOT at your heart's content without any fear of detonation.


The thing is that the FD doesn't take kindly to mistakes so mod it at your own risk.

arghx

iTrader: (3)

just FYI, the engine output is limited when the engine is cold by the double throttle system. The secondary intake ports are closed until water temperature exceeds a preset temperature, (50 or 60C off the top of my head). Nowadays that limit is done with the electronic throttle.

So I'm not even sure you could run your engine all that hard when it is cold because the throttle is forced shut. it's kind of idiot proofed if the double throttle is working.

DaveW

I didn't see the need to be compulsive about regularly changing the (green, ethylene-glycol) coolant mentioned. This is more important in the RX7 than with most other cars because the o-ring ledges (between engine segments) are quite thin. Allowing the coolant to get its anti-corrosion additives get depleted will cause rusting. And if the o-ring ledges rust through you will have oil in the coolant, coolant in the combustion chambers, etc., requiring a rebuild.

I take the easy way out - drain the radiator (about 1/2 of the coolant capacity) every year and replace what drained out with fresh 50-50 mix of green AF and distilled water. That is easy, and keeps the coolant in good condition.

I've done it that way since almost new, and no issues.

Red94fd

iTrader: (5)

Another one.. i am tired seen this type of conversations. They loop around and around. the car is about 20 years old, parts will breake. When new and stock, it could be very reliable if people would had mainteined the car the way it should be.
Moded car is never reliable, it might run well for some period of time depending on thousands of things. Enjoy while it runs and drive it hard as some one said it.

lcdial

iTrader: (1)

This is why this forum is the best! Lots of great info in here! Thanks everyone!

I think the issue is that when you're researching buying and FD, as I was for several months waiting for the right one to find me, you hear such exaggerated claims of unreliability that, when you finally get a car, you're just looking for it to eat itself.

What I'm learning here is that, in the end, it's a car. Taken care of (ie, addressing issues promptly, changing fluids, watching out for issues like high temps), there's no reason it can't last for a long time.

This is great! I'm going to go out this weekend and hit a few 8k redlines -- without worrying so much!!!

Thanks all!

PS-. Mine is an R1, so it should have the dual oil coolers already. I'm told the tune was done by someone trusted, but again, no paperwork. That said, the tune has allegedly been in place for several years with no problems, and judging by the exhaust smell, runs a bit rich -- which, I understand is the good side to err on.

I still have alot to learn about this car and already in your debt for what I've learned so far.

Project88Turbo

iTrader: (22)

Just to add another couple of data points:

My car has 98,000 miles and was on engine 4 when I purchased it. This car was cursed from day one. Within the first thousand miles a coolant leak and overheating was noted, and the water pump was replaced. Then the engine was replaced.

Then engine was replaced again and the main cat was noted as being melted. Then, the engine was replaced with a Mazda reman, and this is the one currently in the car as I purchased it.

When I pulled the engine to clean it and reassemble the externals, the cat was broken and melted. It had never been replaced. This had to play a factor in the engines falling.

My buddy has owned his for over 10 years, and he had the engine rebuilt at 70,000. It did not blow up, the water seals had begin to seep coolant into the combustion chamber giving it the 2 stroke sound until the coolant was cleared from the spark plugs.

In his ownership, the only faults he experienced before this were a leaking gasket at the turbo and the vacuum lines are redone when the sequential system did not operate correctly.


So, I'd say they can be reliable if they are cared for. This is no different than any other car in this respect. I work on VWs and they can be on complete opposite ends of the spectrum depending on the owners care. Ones that are over 200,000 miles and only minor issues or low mileage cars that are completely trashed because no maintainace has been done.

My long standing advice for "Trouble-free driving" is to buy an Accord or Camry, and more recently added the 2nd Gen or newer Prius to that list. But what fun is it to drive those if you like cars.

Vince

Natey

iTrader: (19)

On the Tacome/4Runner club, if you go 500,000 miles and the engine dies, you got a lemon. My old Honda CRX HF got nearly 60mpg. I finally sold it for 2grand at almost 300K miles, still running perfectly.
Some cars are more reliable than others. Period. How many 1993 Subarus or Nissans or Mitsubishis do you see on the road?

I think the FD is surviving pretty well. They only sold 'em (and not many) in the US for 3 years and here we all are, almost 25 years later.

nugget2941

My 1993 fd has 180,000 miles and I didn't need a rebuild until 150,000 or so. The only reason it needed it was I didn't start it for over a year. My mistake. They may not be reliable as a civic, but they are not that bad.

SA3R

I HAVE had the cold start (ran it for only 2 minutes and then shut it down) problem once or twice.

This was due to my idiot gardener/landscaper guy coming around unannounced, offloading his mower and starting to mow my lawns without telling me he was coming to do it- I rushed to the FD, started it up and moved it away from where rocks could fly and hit it.
I then shut it down immediately because I needed the car keys to move other cars away from his stupid mowing and flying debris.

I came back to the FD later to move it again and nope, it was flooded.

Other time it happened was when customs drove one off the ship from Japan and then they shut it off 60 seconds later while I was pleading with them not to do that- they thought they knew better than me. That FD flooded instantly and they then had to tow it around because I wasn't allowed to touch the car until it was given customs clearance.

My double throttle solenoid is not connected, as the barb broke off it. This means the double throttle plates are always full open, so you can give it 100% full throttle when the engine is still cold. I don't, but the car has been running without double throttle for 3 years now with no apparent ill effects.

I've had my car since 2010 and daily drove it through Australian summers and winters as my only car up til about 2015 when I got a beater daily driver car. In all those years the only problem I had was the coolant temp sensor failed (causing the car not to start or run) and that was an easily replaced, $40.00 part.

My daily driver/beater car is an Australian GM sedan with an LS V8 engine. It gives more trouble and fails much more often than my FD ever has. The FD is now the "reliable backup that will always go" when the LS car inevitably fails- craps out a water pump, coil packs, engine computer, ABS system, or power steering.

The FD proudly waits in the garage, and (probably) silently laughs at the silly LS6 V8 daily sedan and its delicate composure.