If you are having trouble with some of the terms or abbreviations used in this section, please feel free to click our acronym and abbreviations sections here:  http://fc3spro.com/abb.html!

We have tried to create this buyers guide to be useful for those looking to purchase a potential FC3S turbo.  This guide will ultimately link with a lot of pages already written for the "Problems" section - http://fc3spro.com/TECH/PROBLEMS/problems.html, as alot of info is cross-referenced between the two sections.  Information will try to narrow to FC3S-specific areas, but we will include a "Preliminary" section to address most universal topics on buying any used vehicle.


Preliminary:
There are helpful resources on the web that allow you to get a good idea on current vehicle prices.  Kelly Blue Book is located at:  http://www.kbb.com/ and is a good place to start if you have no idea on prices.

In additon to the above, you need to do a thorough check of the chassis from as many vantage points as possible.  This includes... Most of the above information in this Preliminary section can be applied to almost all vehicles when looking for a potential used car to buy.  The subsequent sections will cover more specific areas to the FC3S turbo!


Engine:
The engine is about the most important (and expensive) part of the car.  If the engine isn't in good working condition, the car is literally worth dirt.  A good rebuild will cost in the neighborhood of $2,000 - almost everything else on the car can be bought for several hundred dollars from a wrecker (if you can locate one).  J-Spec engines (engines imported into the U.S. from Japan) can be bought for about $1,000, but it's not a 100% guarantee those engines will be good; even with warranties, the hassles of losing labor on removing and installing the engines and shipping it across country is a lot of headaches!

Most of these vehicles are rolling over 100,000 miles or easily above that.  FC's with original engines with this kind of original mileage will need a rebuild soon, especially if you're going to chase higher performance output; the apex seals on a 100,000 miles engine is too thin to take any more abuse, especially when boost starts to rise.  Replacing these out-of-tolerance apex seals necessitates a complete tear-down, so you might as well rebuild the entire engine at the same time.  Keep in mind, a full set of OEM Mazda parts is going to cost you $1,000 very easily.  Add in the labor costs for an engine rebuild, and it easily eclipses the $2,000 mark mentioned earlier.

It is very hard to ascertain the condition of the internals of the engine very easily, and the agreed upon method is a compression test.  A rotary engine would normally require a specialized Mazda meter, but most people don't have access to one locally; you can try and contact your local Mazda dealer to see if they can do a "rotary engine compression test" for you.  A piston engine compression tester is usually used as a substitute; we need to bypass or remove the check valve that keeps the highest compression reading in the gauge.  By defeating the check valve, we can monitor the three faces of each rotor easily.  The key to this "modified" compression test is to shoot for three, even bounces on the compression tester gauge needle.  Uneven bounces would indicate a bad seal.  Readings between front and rear rotors should be pretty close; the Mazda tolerance is around 20psi between front and rear rotors.  "Good" engines should be able to hit around the 100psi mark.  Anything lower than 70psi is indicative of a tired engine that needs a rebuild.  Bottom line is you want even readings from all rotors face and from front to rear rather than several really high peaks mixed in with a bunch of lower ones.  Any uneven readings is a hint of a possible blown engine.

Any hints of engine damage should discount the vehicle to the "under $1,000" category; the car is only worth several thousand in "pristine" condition - check the KBB site mentioned at the top of this page.  FC's with engine trouble should not be bothered with unless you're able to do an engine rebuild and fit it in your budget.  A chassis with a blown engine can be an economical path to owning an FC turbo, as J-Spec engines keep an engine swap pretty reasonable.


Turbo:
It's only natural to mention the turbo right after the engine; most people seem to always ask about them pretty early in the conversation.  The only real way to check the working condition of the turbo is to take it out for a test drive.  If the car already has an aftermarket boost gauge, that'll help a lot.  A stock Zenki FC turbo produces 5.5psi, while a stock Kouki FC turbo producs 7.5psi of boost.  On the stock boost gauge this is about 1/2 to 2/3 up on the gauge sweep.  The power should come on smoothly, with the Zenki producing turbo power at 4,000RPM, while the Kouki FC turbo produces power a little lower at 3,000RPM.

ANY abnormal noises while the turbo is spooling is bad.  Cars running cone filter intakes can produce higher levels of turbo noises, so don't be alarmed if your vehicle has an open filter system.

The stock turbos usually last 80,000 - 100,000 with proper care.  Rebuilding is relatively cheap as the stock Hitachi units are designed like the Garrett T04 turbos units; any Garrett turbo shop should be able to sell you a turbo rebuild kit for a little over $100.

Zenki turbos are pretty cheap to replace, as good, used units are for sale for under $100; you really should not pay more than $200 for a good Zenki turbo, as there are lot of them out there for sale.  A good Kouki turbo, OTOH, is a bit more rare and commands more money to purchase.  Typical prices for a good, used Kouki turbo is starts easily at $300 and goes up.

While test driving, if the exhaust suddenly starts to smoke while under boost, the turbo needs to be rebuilt.


Transmission:
Next to the engine, the transmission is probably the most expensive part of the car to replace.  A transmission rebuild from a reputable transmission shop is at least $1,000!  Note, all North American FC turbo only came with 5-speed manual transmissions; be wary of owners who claims they have an "automatic turbo".  Outside of the U.S. and Canada, there were automatic turbo models, so this really applies to any U.S./Canada vehicle.

The transmission is also one of those components that takes the most abuse from (bad) drivers.  Synchros are usually the first to go then the gears themselves.  The transmission should not be making ANY noises at any time.  Under normal driving, the transmission should shift gears smoothly and quickly.  Grinding during shifting should throw up a red flag; the problem could be as simple as a failing pilot bearing to a failing gear.  ANY transmission work is costly, as labor rates for removal and replacement is usually set at $300 from the Mazda dealer.  This means you need to pay a minimum of $300 (to the Mazda dealer) to even look at the problem!

A "sloppy shifter" problem can cause excessive rattling, but it can eliminated (when trying to isolate the transmission or the shifter) by holding the shifter to see if the abnormal noise goes away; the floppy shifter problem can easily be fixed by replacing the worn shifter bushings: 
http://fc3spro.com/TECH/PROBLEMS/DT/TRANS/flopshift.htm

A worn clutch can be easily diagnosed through this procedure: 
http://fc3spro.com/TECH/PROBLEMS/DT/CLUTCH/clutch.htm

Keep in mind that due to the big differences in ratios between 1st and 2nd gear, any shifts up at redline will result in a nasty grind from these transmissions - keep shifts from 1st to 2nd under 6,500RPM.

Good, used transmissions usually go from $250 to $500.  New clutches are usually around $200 - $350 for a "clutch kit", which includes the clutch disc and pressure plate.


Rest of Drivetrain:
This would include everything behind the transmission.  For the most part, the rest of the drivetrain is usually problem-free and can handle a fair amount of abuse.  Unless the car was severly abused (transmission would tell you), everything behind the transmission should be in good shape.  About the only common problem is "clunking" during acceleration, which would point to a possible failing front differential mount.  This would include:  driveshaft, rear differential, rear axles.

The driveshaft is designed with non-rebuildable u-joints.  You can get the original retrofitted with rebuildable u-joints from a reputable driveshaft shop.

The rear diff can take a lot of abuse, even from mildly modified engines.  If you do hear definite grinding noises from the rear of the car, especially during turning, then the rear diff needs to be examined - you really should stay away from a car that makes grinding noises in the rear unless you're prepared for the worst, a dead rear diff.  The FC turbos all came with LSD's in North America, but they do not exhibit any noise during normal operation.  Even with this "bonus", most Zenki FC turbos will already have worn LSD's, which usually kill their clutch packs within a paltry 30,000 - 50,000 miles; Kouki FC turbos run viscous LSD's which last a lot longer.

The axles do have CV boots on them, as the IRS design requires it, but these CV boots are a little more robust than FWD vehicles due to the fact that the tires never turn.  A quick peak underneath with a flashlight should show the CV joints on the rear axles in good shape.  If the CV boots are torn, be careful as the entire axle (side) could be bad.


Under the hood:
Keep in mind if you need to pass emissions or not.  If local emissions test require a visual, you can't have things missing or have a lot of shiny, aftermarket parts under the hood.  Typically, most FC's have lots of hard, rubber vacuum lines that are very brittle; check for broken vacuum lines, especially over the turbo where heat is concentrated.  Silicone vacuum lines is a good idea, even though it might pique the interest in an emissions test.

The wiring is also prone to turning brittle; a quick visual check to see if the wiring has been compromised is a good idea.  Check the area behind the alternator, as the engine wiring harness tends to abrade easily back there.  As with vacuum hoses, check the wiring in and above the turbo, as the heat causes the wiring to fail easily.  Most suspect are the wires for the O2 sensor and ACV.

Very slow coolant leaks can sometimes be spotted for the tall-tale sign of white crud in and around coolant fittings.  Check the radiator hoses (upper and lower), thermostat cover (upper radiator hose clamps onto this), and the radiator itself.  The stock radiator uses an aluminum core with plastic entanks, and the crimp edges can develop leaks.  [MORE]

Oil leaks can spring up from a number of places.  If the engine is pretty dirty, look for really dirty areas where dirty and crud have accumulated.  Dirt and crud do not normally stick to clean surfaces, so the oil helps them to stick to the engine and engine bay.  A good-sized oil leak would still be wet with oil.  There are a number of places that are common oil leak areas: If you can get the engine to start and idle, the engine should run pretty smoothly.  If the idle is loping or lumpy, it could be due a number of problems.  While under the hood, also check: Some specific parts that should've been changed by now.  Ask the seller if they have all been changed or be prepared to pay for the maintenance yourself (i.e. start deducting more from the asking price!).
Starting the engine:
The engine should crank and start in about 2 seconds (1 Mississippi - 2 Mississippi) which would correspond to 3 revolutions of the engine, if you can count them by ear.  Keep in mind that the engine starts easier when it's cold - always remember to to a hot-start (restart engine after engine fully warmed up), as it should start at about the same time as a cold-start.  Any problems with a hot-start could indicate potentially expensive problems with the engine; a hot-start problem could be simple engine flooding (i.e. dirty fuel injectors) or a tired motor (i.e. bad compression).  Whatever the case, be very wary of an FC that has hot-start problems.

The idle should be steady and at 750RPM, which is Mazda spec.  Variation is stated at + or - 50RPM, so idle should read anywhere from 700RPM to 800RPM.  Be wary of cars that have elevated idles, as the idle could be bumped up to cover other problems.  Intake vacuum leaks are notorious, and bumping the idle is a trick to get the engine to idle steadily enough to mask them.  Whatever the case, an FC idling 1,000RPM is higher should be considered suspicious.

When the engine is idling steadily, check around the car for any leaks.

Watch the exhaust for any hints of smoke.  A very slight trail of smoke is okay.  Prolonged smoking, even minute, is indication of a tire turbo or tire oil seal in the engine.  The "acid test" of the engine oil seals is to rev the engine to 4kRPM and hold for at least 15 seconds.  If smoking starts to pour out of the exhaust, the engine oil seals need to be replaced.  Replacing the internal oil seals requires tearing the entire engine apart - in essence, it's an engine rebuild.


Test driving:
The car should drive very smoothly from a stop.  Keep an eye on the tach to make sure the engine revs smoothly down to idle speed when coming to a stop.  Keep an eye also for the infamous 3,800RPM hesitation by allowing the engine to rev repeatedly through that RPM range while driving.  The engine should also pull smoothly all the way to redline; the engines were designed to rev occasionally to redline, so a knowledgable owner should not be surprised by you trying to do so.  High RPM hesitations can be indications of fuel pump/filter, ignition, or TPS problems.

There should not be any abnormal noises coming from the chassis.  "Clunks" produced from accelerating from a stop or slowing down can be indications of broken engine, transmission, differential, or front upper strut mounts.

A quick test for the clutch is located here:  http://fc3spro.com/TECH/PROBLEMS/DT/CLUTCH/clutch.htm

Brakes should stop the car quickly and smoothly.  The FC is known to have a fairly "soft" top pedal travel, so don't be alarm if the top 1/4th of brake pedal travel doesn't seem to be doing anything.  As long as the car repeatedly stops at the same pedal travel point all the time, the brakes are fine.  If the brake pedal is "spongy" or doesn't respond very well, that could hint at a potential brake job - at the very least, a brake bleed.

Remember to boost the turbo a little and keep an eye out on smoking coming from the exhaust!


Interior:
Plastic trim pieces are very brittle, so finding broken or missing pieces should not be surprising. A lot of the interior electronics are notorious for going bad.
Miscellaneous:



To conclude, most Zenki FC turbos should go for about $2,000.  Kouki FC turbos should go for about $4,000.  We regularly find "bargains" which include either blown engines or other "major" problems (we rebuild engines or swap other parts) or ignorant owners which cannot perform basic troubleshooting (problem turns out to be a flooded engine or loose hose clamp).  These bargain cars are bought at $500 or cheaper!  I realize that there are some people who have a hard time trying to locate these cars locally, or they are just very rare to come across.  Try some of the online car selling listings as listed below if you're having a particularly hard time trying to find one; these cars also regularly pop up on eBay.
http://www.cars.com/
http://www.autotrader.com/
http://www.thepartstrader.com/
http://autos.yahoo.com/
Classifieds 2000 Autos
RX-7 Forum - For Sale, 2nd Gen RX-7




Questions?  Comments?  Send email to:  reted@fc3spro.com

10/12/2003