Editor's note: Dave Disney has an edited version of this on his site, cleaned up and with some additional info added. It can be found at: http://rx7.voodoobox.net/infofaq/bguide3g/bguide3g.html
But I have a slightly different take on a couple of items, so I am leaving this up. I don't think they are major differences, so they should really be about the same. --Steve
_______________
Date: Thu, 16 Apr 1998 21:28:52 -0500
From: tom (jelkil@interaccess.com)
The following is a primer I have compiled for those who are contemplating the purchase of a 3rd gen RX-7, but for one reason or another are fearful of its reliability record. This has come up many times on the list, in private email and on the NG. If you have something to add, please email it to me so I can repackage it and then have someone (Steve C?) add it to their website.
THINKING ABOUT BUYING AN RX-7 BUT HAVE HEARD HORROR STORIES?
The 3rd gen RX-7 is a great car, but it does have some problems. These problems by themselves are not serious in nature, but if not addressed can lead to catastrophic mechanical failures that may damage the reputation of the marque as well as put a sizeable dent in your wallet. You must remember that this is a high performance vehicle and requires maintenence commensurate with its capabilities. I will address each item in order of importance, with the most critical items last.
The RX-7 has always been a high performance sportscar as each new generation was introduced. With performance often exceeding competition that was priced far in excess (or for that matter, a multiple) of its purchase price, there are some areas where sacrifices were made to save money, while developments in the high performance aspects of the vehicle were well represented.
The least critical of these areas are interior trim. The black console, door and dash panels were, on the 93 cars at least, coated with material that would not hold up. Many of these early cars had these panels replaced under warranty. Some early cars also had exterior paint problems, where the color coat did not adhere properly to the primer. By now most of those cars have been touched up or completely repainted, so don't disqualify a repainted car as a candidate for purchase. (Ed. note - the '95s at least did not have these problems.)
Another area of concern is instrumentation. The oil pressure sending units in all 3rd gen cars are of poor quality and should be replaced with a good aftermarket mechanical guage or electrical guage and sender. (It is normal for these cars to show low oil pressure at idle). The water temperature gauge is also too heavily center weighted, so that even an overheat condition will show only as slightly high. This too should be replaced w/ an aftermarket gauge. The car lacks a boost gauge, which should be added and is indespensable for the diagnosis of engine or engine control problems.
There were 3 recalls on these cars- brakes (vacuum hose modification), new (high temp) fuel lines and cooling system (pressure cap and fan control module). These should already have been performed by now.
The inadequate ground wires between the engine and body should be supplemented with heavy duty cable. In some cars this will remedy the 3000 rpm hesitation that occurs when not fully up to operating temperature.
There are some vehicles with 5th gear synchro problems. The use of Redline oil should prevent the problem from developing in the first place.
Because of the complexity of the sequential twin turbo control system and the turbo system itelf, the area under the hood is quite crowded, and underhood air temperatures are very high. This causes the hoses used for vacuum and pressure operated engine controls to harden and crack. These hoses should be replaced with tie wrapped silicone hoses that can withstand much higher temperatures. This is a job that involves a good bit of labor (approx 6 hours), but the materials only cost about $35. Coolant hoses, especially to the turbos, must be replaced regularly or with silicone ones. There also is a website outlining a $30 cooling system mod that should be performed as soon as you get the car- there is an expansion tank that frequently fails, and the modification eliminates this tank. There is also a <$10 modification to allow the fans to work after the engine is shut off, this should also be added. Proper (read- not too tight) belt tension is essential for water pump ($200-600)longevity.
The exhaust system on the 3rd gen car consists of 2 catalytic converters, a front unit in the downpipe and another large unit under the floor. The front converter has a reputation for disintegrating and subsequently clogging the main one, which results in skyrocketing exhaust temperatures and probable engine failure. A large number of 3rd gen cars have had engine replacements as a result. The current year (Japan only) cars no longer have this first cat, just a straight downpipe w/ no cat. If legal in your area, I recommend replacing it with a straight through downpipe readily available from the aftermarket. Besides significantly lowering the egt, it will also lower the underhood temperature, extending the life of all underhood components.
The Mazda dealer service department may be the greatest threat to these 3rd gen cars. DO NOT go to a dealer for service unless you get a recommendation FROM ANOTHER RX-7 owner first. Many dealers are not properly trained to service these cars and do more damage than repairs, but there are enough dealers and independent shops that specialize in this particular vehicle that service should not be a major problem.
These cars, when fitted with just a few bolt on modifications, are capable of tremendous horsepower gains, but these modifications must not be lightly undertaken- proper fuel enrichment to accomodate intake and exhaust flow improvements MUST be provided. If you are purchasing a modified car, make sure fuel enrichment has been taken into account.
Remember, for a combined total of under $600 in reliablility upgrades (if you do most of the work yourself), you can have a bulletproof rotary rocket capable of embarassing some very exotic machinery. There is no need to be afraid of the car. It just requres proper preparation, that although is not required for you basic Honda, will put a huge smile on your face when you put it through its paces. As you surf the web, take a look at the enthusiasm you see in the (many) RX-7 websites you'll see. Racers, engineers and other technically oriented types are HIGHLY represented among the ranks of owners. People love the car for a reason, and these people wouldn't be so dedicated to the model if it wasn't so special.
From: Steve Cirian (steve@ScuderiaCiriani.com)
A compression test would be one thing a lot of people recommend. Since the rotary engine requires specific test equipment, a Mazda dealer will need to do this.
Do an in-the-car boost test on the test drive if the car is equiped with a boost gauge. (For some reason Mazda did not include these on any model.)
Some cars have suffered O-ring problems.
The car should NOT smoke. Oil leaks show up as blue smoke. (Not sure what this is in a rotary, but in a piston engined car would be bad rings. In a rotary, it would probably not be bad apex seals, but it is still not a good sign.)
White smoke usually means that the engine is getting water/antifreeze into the comustion chamber. Someone mentioned that this is due to bad seals (these seals cost about $400 as part of a rebuild - not sure what the rebuild would cost if you had to rebuild due to them.) That person also mentioned that the water in the engine caused it to burn too hot, and ruined the apex seals. Parts of the seals went through the turbos and ruined them as well.
Black/brown smoke usually means the car isn't burning all of the fuel going in. This rich condition is probably nothing to be worried about if all the car needs is a tuneup.
Check for paint chips if the car is a '93.
Check the paint under twilight conditions, or at a gas station that has fluorescent lights, as this will make it easier to see mismatched paint (from repairs), swirls, and other paint defects. Bright sun / bright lights at the used car dealer will hide defects. Dark at night will as well.
The 93s also had some problems with the console peeling. The early cars had these painted instead of having the color mixed into the plastic. This is fairly easy and cheap to fix by replacing the panel.
Ask if the car has ever been in an accident. Frame damage is forever. The hoods are aluminum, and the bumper covers are plastic, but other than that a refrigerator magnet should be used to check for Bondo.
Have the car inspected by a dealer who is reputable as RX-7 knowledgeable. These dealers are hard to find.
Check the price on the:
The Competition Yellow Mica color cars seem to be worth a lot more. The rest of the cars should be priced about what the blue book says. Silver may be worth a bit more due to the rarity of these as well as the yellow ones. Low mileage will also be worth more.
Stay away from any car with a Rebuild Title. This usually means the carwas stolen, totalled, and then resurected. Probably all sorts of problems.
Check the vehicle history on the Vehicle History Report website. VHR will sell you a report on the car you are looking at for $19.95. You just need to know the VIN. Or call 800-633-7834.
Also see: EZ Title Search
One more thing - a lot of people that are looking at used 3rd gens usually see tons of cars for sale that have had the engines replaced. I suppose an owner who experienced a blown engine would be a lot more likely to sell. Most people who have no problems with the car aren't selling :-)
Date: Wed, 6 Jan 1999 16:59:10 -0600 ...do yourself a favor and spend the $20 to instantly lookup the VIN/title-history with
something like carfax or similar site.
Date: Fri, 14 Apr 2000 22:36:34 PDT I have the SCC that has the first article on their RX-7 Project Car.
it is the December 98 issue. It talks some about Things to look for.
blah blah blah
Shopping Around.
When looking for a used Rx-7, it is especially necessary to be patien and
discriminating. Do not be surprised if you look at a dozen rx7s before
finding a good example. When it comes to milage, the lower the better.
There are far too many ways for careless owners to abuse and neglect the
rx7. Oil changes should have been conducted regularly at every 3,000 miles
or less. The car must never have overheated in any circumstance. Further,
there are many examples of used rx7s on the market that have been
"ruthlessly thrashed" on the race circut or damaged by an unexpected off
road excursion.
There are three recall notices that must be done to any perspectice rx7 is
not completed already. The first is a coolant recall which replaces parts
of the cooling system(water pump seal, thermostat gasket, upper radiater
hose, etc.) with stronger and more heat resistant materials. The second
recall involves the braking system and replaces a check valve and hose
leading to the brake booster. Without this simple recall, the valve may
stick under certain conditions and hinder power-assisted braking. The third
and final notice that will need to be taken care of is the fuel system
recall which replaces certain fuel lines under the intake manifold with
lines made fron material more resilient to the extremely high levels of
under-hood heat associated with rotary-powered vehicles. One can also call
Mazda's Custon Service line at (800) 222 5500. With the vehicle's VIN, they
will be able to determine which , if any, recalls have been applied to the
particular car. Unperformed recalls can be taken care of, free of charge,
by any Mazda dealership.
There are a few more problems typically associated with the earlies third
generation RX-7. Most apparent is Mazda's lees-than-perfect painting
process. Premature paint chipping is ussually isolated to the car's hood
and the rocker panels aft of the rear wheels. This problem was eventually
solved when a more traditional panting technique was applied at the factory.
Another aesthetically challanged area of interest is the RX-7's plastic
interior that has been known to peel terribly over time. This problem was
likewise fixed by the factory. Finally, when shutting the drivers side
door, don't be surprised if it takes a good slam to close fully. The doors
on RX-7s are notorious for their high effort requirements. Then again,
anyone to weak to operate the door on a high performance sports car is too
[much of a pussy] drive one, 'nuff said
The Test Drive.
Perhaps the most revealing analysis of the RX-7 will be conducted during the
test drive.If the car is started when cold, the engine should immediately
jump to 3000 rpm. Mazda refers to this function as the "accelerated Warmup
system". You should think of it as cruel and unusual punishment. Gently
'blipping' the throttle should drop the engine speed to 1500 rpm. After a
few minitues of conservative driving, the idle should settle between 750 and
950 rpm. If the car has very low milegae(less than 20,000) the engine may
idle slightly higher due to a "mileage switch" that is activated during the
ectended break-in period., Another unusual quirk of the car is a notical
fuel-related hesitation at 3,000 rpm when the engine is cold. This is
completely normal and should lessen dramatically as the car warms up. It is
also very important to remember that with rotaries, like conventional piston
engines, most internal wear and tear occurs during cold opperation. During
this time, it is absolutely imperative that driving at high rpm or under
boost should be avoided at alll costs.
Once the car is up to operating temperatures, the real evauluation begins.
Unfortunately, a stock RX7 is not equiped with a boost gauge making boost
testing more of a "seat of the pants" experience. It may not be too
unreasunable to bring a boost gause and vacuum line and tap it into the
small nipple on the passenger side of the intake manifold before the test
drive. The vacuum line could then be fed under the hood and through the
windor to the gauge that can be taped to the dash
To check the boost pattern, cruise in 3rd gear at 35. As the road ahead
clears, accelerate under wide open throttle. Boost levels should quickly
spool to 10 to 12 psi. Just above 4500 rpm, the boost level should drop
breifly to approxamitly 8 psi and then slowly build up to 10 psi by redline.
If boost levels are unusually low or erratic, there could be problems
with the complicated turbo control system of the turbos themselves. Listen
carefully for knock under prolonged boost[heh heh]. Knock can be caused by
running inexpensive, low octane gas or by lean run conditions caused by
clogged injector sor dirty fuel filters. If detonation is detected, lift
off the throttle immediately and look for cars elsewhere. In a rotary, if
you hear a knock, the motor is already likely to be damaged.
A characteristic common with rotaries is their lack of low end tourpue. If
the engine speed drops below 2k, the car is essentially crippled. However,
right around 2500, the turbos quickly come to life and things start to
happen,, Upon first drives, the car may feel "jumpy" when tooled about
around town. Eventuallky, the driver will get used accustomed to the unique
throttle management required by the powerplant.
RX-7s are also known to exhibit a chronic hood latch squeak that can drive
some owners into fits of frustration. This noise can be fixed easily, sa we
will see in this project series. Clunking noises from the supension, on the
other hand, are not so readily ameliorated. Cars manufactured before May
31, 92 (check drivers side door jam) come equipped with an anoyingly noisy
upper a-arm bushing. This can be replaced with an updated version, but at a
remarkably high labor cost.
The trans should shift precisely and smoothly. It is not uncommon for rx7s
to develop 5th gear syncro damage, typically cause by a botched 2nd to 3rd
gear shift. If damage is present, shifting quickly from third to 5th
gear(without letting the engine speed reduce) will result in a terrible
grinding sound. Repairing a 5th gear syncro is very exspensive since it
involves removing and dissassenbling the tranny. Finally, check for warped
rotors, cracked wheels, engine leaks and the typical areas involved when
inspecting a used car.
It is also a good idea to check the water temp gauge toward the end of the
test drive,. The needle should point slightly below the middle temp range.,
Also criticle to the longevity of the motor and turbo is a niuce cool down
period of at least thirty secons. Spirited driving on the treack can
require up to 5 minitues of cool down to let the iron and aluminum
components of the engine recover from their tnermal exspansions. It is also
normal to hear the boiling and bubbling sounds fron the engine after the
ignition has been turned off.
Date: Sat, 9 Jan 1999 11:15:52 -0800 Check out Felix's web site
and look at "How do I know if my engine's apex seals are OK?"
Date: Thu, 16 Jul 1998 11:11:33 -0600 What are some suggestions regarding inspecting a vehicle prior to purchase?
The current owner has been upfront that the engine is due for a rebuild (has
over 100K miles). I'll be flying to Dallas tomorrow to check it out and, if
it checks out ok, accomplish the transaction. Then I'll drive it back to
Colorado ... carefully in the heat.
I currently own a '93 R1, so I'm not new to the breed. However, he has done
quite a few modifications to his car, whereas mine is basically stock.
Here are some things that occur to me ... what do you think? What else?
1. He'll pick me up at the airport in his other car. I want to do my
initial check-over with the car cold. I'll make sure that all the
aftermarket pieces he advertised are still on the car. I'll also ask him to
track down the receipts and owner's manuals for these add-ons.
2. Generally look for leaks and problems in the engine compartment.
Another potential buyer had a compression test done, and the numbers were
low (in the 6.0:1 range), so the engine is understood to be in so-so shape.
Confirm that visible hoses have been replaced with silicon hoses.
3. With the engine and car still cold, use the jack-stand to remove one or
more wheels, and look around under the car. The current owner indicates the
rear brakes were redone recently, but the fronts are pretty worn and due for
replacement. Check for play in the bearings and bushings.
4. The current owner indicates the tires are pretty worn out. Look them
over for signs of mis-alignment, abuse, and whether they are up to a 700
mile trip in 100+ degree temperature. Look over the wheels closely, as '93
wheels were prone to cracking. Check air pressure.
5. Check out the turn lights, brake lights, headlights.
6. Wash the car in the shade, and look over the condition of the paint,
brightwork, glass, etc. Look for evidence of the car being wrecked.
7. Check the condition of the seats, under the seats, seat runners, carpet,
glove box, storage compartments, spare tire, seat-belts, sun roof, windows,
etc. The current owner indicates there is some degree of interior peeling.
8. Check the condition of the radiator, a/c condenser, and other parts in
the front of the car that might have taken some hits from road debris.
9. Condition of adjustable shocks. Bounce car up and down. Make sure I
understand how to make adjustments. During road test, make changes and see
if the adjustments seem to be doing anything.
10. With the hood open, have the owner start the car, and listen carefully
as it warms up. Check out the fan and air conditioning.
11. Let it run a minute or so, watch the gauges, and then turn off the car.
Listen carefully, and look around for fluid leaks (oil, coolant) and
oddities. (However, my understanding is that RX-7's don't like to be run a
brief period of time ... oil pools in the housing or something?)
12. Make sure the "turbo timer" is working ok. Get user manual if still
available.
13. Initial city road test with current owner driving around the
neighborhood and parking lots: 14. Highway road test with current owner driving: 15. Find open area, and do the 3rd gear WOT test. Watch for boost levels
and spikes on the boost gauge.
16. Conduct road tests 13, 14, and 15 with myself driving.
17. May be hard to do, but find an open area (early in the morning?) where
it is possible to drive aggressively. "Toss" the car in left-to-right
transitions, a'la a slalom. Drive like a simulated autocross with hard
turns, accelerating out of turns, and hard braking.
18. Find a quiet place and give myself time to collect my thoughts about the
purchase itself.
Other questions:
1. Is it practical to visually inspect the turbos for cracks in the
housing? What else can you look for. He has a boost gauge, so will I be
able to get a good idea of the condition of the turbos from that? He claims
a 3rd gear WOT pattern of 12-10-12 (which seems very good)
2. Are there inspection plates that it would be practical for a
non-mechanic to open and look at? Clutch? Turbo actuators?
Date: Tue, 24 Aug 1999 22:18:17 +0000 While I have no data to back this up, the general feeling is that
rotary engines do best when driven with spirit. Built-up carbon can
break up under the wrong circumstances and create real problems
with a rotary. The low mileage and "pampered" nature of the
particular car you mention suggests that it never really had a
chance to clear its throat. These cars tend not to do well as
garage queens.
The usual mode of "sudden" failure for a rotary is a broken apex
seal. However, I have not heard of the failure described as your
friend did--similar to the car going over a bump. Usually there is a
mysterious loss of power combined with a lumpy idle. I am not
saying the motor was not lost--only that this may have been a very
unusual case. Unfortunately, the dealer will trade the old engine for
a Mazda Rebuilt one, so no one will know what let go internally.
Most 1st and 2nd gen N/A RX-7 owners fall into two categories:
The first group owns commuter cars. They take minimal care of
the cars, but the cars are run daily, and have served their owners
well for many years. These are the beaters you still see on the
road. The second group is made up of enthusiast cars--often
modified, and sometimes not too wisely. These engines typically
have "moderately" shortened lives, but no one cares because that
is part of the trade-off for heightened performance. Engine life in
the fast lane is still quite acceptable for the level of performance
attained.
Finally, you need to be aware that a primary weakness of a rotary
is not the engine itself, but the fact that it is composed of
alternating layers of steel and aluminum--sealed with large O-rings.
A single episode of over-heating due to a burst water hose can
warp the layers relative to each other and compromise the O-rings.
People used to steel piston engines are used to not worrying about
water hoses until something breaks. Mazda doesn't tell
unsuspecting owners about this situation, so a lot of engines are
lost when the first hose lets go. To make matters worse, Mazda
uses bogus water temp gauges, designed not to startle the car's
owner with unnecessary movement. By the time you see the temp
rising, it is often too late to save the engine.
People on the outside think rotaries have a bad reputation for
breaking, but those of us who care enough to learn about these
powerful yet small engines realize that they are actually unusually
robust, putting up with poor care and hard use from their owners
without a wimper. If you do proper maintenance, change the water
hoses every 50,000 miles or so, keep the cooling system in top
shape, and beat the heck out of the car on a daily basis, you will
love rotaries for the rest of your life.
Turbo rotaries (T-IIs and 3rd gens) require a bit more TLC from their
owners, and are more easily screwed up by unwise modifications,
but are still capable of long engine life. The
price/performance/complexity envelope of these cars is several
notches above the N/A machines, and they were/are built for an
enthusiast driver. It is very hard to gauge the innate reliability of a
T-II or a 3rd gen because relatively few "factory new" cars made it
to old age without being unwisely modified. Many T-IIs had
problems after the stock exhaust system wore out. Owners
replaced them with aftermarket units for "more power" and to save
money--not realizing that exhaust back pressure from the stock
system was necessary for proper boost control. Boost went up
beyond the stock ECUs ability to provide fuel and engines started
to break.
Many 3rd gens fell victim to bad dealer work, including such
silliness as replacing engines in an unsuccessful attempt to cure a
problem caused by something as simple as a split hose or a
clogged cat. The engines got a bad rap for breaking when they
were in fact quite fine. The dealer would then screw up the engine
replacement, and the owner would end up with a poorly running car
and no one around to fix it. This problem was the result of poor
dealer tech training combined with a very complex engine
management scheme. Now you know how the rotary got a
reputation for being fragile.
Fortunately, there is a non-dealer network of highly skilled
specialists out there who can take a 3rd gen and make it anything
from a very reliable street machine to an all out track racer. There
are also dedicated T-II owners who have nicely documented
solutions to typical problem areas on their cars. In fact, I would go
out on a limb and say that the T-II is one of the prime platforms in
the world from which to build a relatively low budget supercar.
I hope this helps you understand more about the world of rotary
engines and gives you the confidence to pursue your own interest.
One thing I will guarantee you. If you decide to try and find a good
car, you will find all kinds of help from the equally good people on
this list. Just bring us into the process before you plunk your
money down. Hopefully we can help you get started in the right
direction by steering you to a good local mechanic who can
evaluate the car.
[Mail me]
[To Lightning home]
[To my home page]
[Copyright Notice]
From: "Eng, Cary"
From: "Travis Miller" (travisrx7@hotmail.com)
From: "Derek Vanditmars"
From: "Lynn Allan"
- Slow speed turns
- Slow speed braking
- Lots of low to medium rpm easy shifting, including reverse,BR>
- operation of the fan, air conditioning, gauges
- higher speed turns, braking, shifting.
- Slow speed braking
- Lots of medium to high rpm shifting. Avoid "power shifts", but do
some of the shifting quickly to check for synchro problems (especially 5th)
From: "David Lane" (dlane@peabody.jhu.edu)