Common Problems

I've received a few emails from people who have just purchased second-hand Corollas asking about any particular trouble spots they should look for. Aside from the usual stuff to look out for on used cars, I'll also list items that are common with the AE92 Corollas. If you have any other stuff to list, lemme know and I'll add it.

You should also check out ALLDATA.COM for any Technical Service Bulletins and/or Recalls that your car may have. This particular link only applies to the 1988 Toyota Corolla GT-S with the 4A-GE (EFI) engine. Although the list is long, only a few of the items are actual problems that were reported as being major. Most are just memos and such...

Anyway, here it goes...

• Compression
  The 4A-GE engine is robust for a small displacement engine even by today's standards. When checking out a car you want to buy, rent or borrow an engine compression gauge. Test drive the car enough to get it up to normal operating temps. Pull the spark plugs and insert the compression gauge into each cylinder, one at a time. Pull the EFI main relay (it's cylindrical) in the engine bay fusebox and disconnect the connectors going to the ignition coil. That way, there's no spark and no fuel going into the combustion chambers. Go inside the car, floor the gas pedal, and crank the engine 3-4 times. The minimum compression for each cylinder in a TVIS engine (pre-'90) is greater than 142 psi w/ less than 14 psi difference between ALL cylinders. Low compression and/or a big compression differential will mean the engine will need a costly rebuild.
• Tell-tale Oil
  Previous owners usually tend to think of Toyotas as bullet-proof. In many ways, they are, but running an engine without enough oil will kill any engine out there! This is more prevalent in Corollas that have the nicer 4A-GE engine for some reason. Remove the valve covers to take a look at the valvetrain's condition. Excess dark sludge and/or milky-looking clumps are a bad sign. Check the oil level and keep track of how much you add.
• Stuck Starters
  I'm not sure why the Toyota engineers didn't place the starter on the intake side of the tranny where things are nice and cool. Nope! On the GT-S, the starter is sandwiched between a relatively hot engine block and an even hotter exhaust manifold. To their credit, they installed decent OEM heat shields on the exhaust header and starter. Don't be surprised when you get back to the car and the starter won't turn--acute heat soak. The problem's worse if you use aftermarket exhaust headers that don't have heat shields like the KBD unit I'm using. Solution? Fabricate your own heat shield using a sheet of 304 stainless steel and weld on some mounting tabs on the header. You can also buy some of that "heat wrap" for starters that they sell at speed stores. Be sure to check my starter circuit diagnostic tech.
• Old Oil Cooler Hoses
  It's a good idea to replace all four (4) oil cooler hoses. Like other hoses, they'll eventually deteriorate to the point of cracking open and letting all of the oil leak out. Result? Seized bearings.
• Engine Leaks
  The front side seals of the engine usually wear out quicker than we'd like. The result is a big, messy oil leak on the timing belt side of the engine. If you've cleaned the timing side of the engine and see oily grime on it 2 days later, it's most likely a bad cam or crank seal.
• Flooded Valleys
  We all get the urge to clean the engine bay every once in a while. Be careful, though! If you get too much water in the valve cover valley, it'll flood near the spark plugs and the engine will misfire or not start at all. It's happened to almost every GT-S owner I know (including me!), so don't feel bad! =) Just remove the valley cover and sop up the water.
• Pesky Parking Brakes
  I've heard that the parking brake mechanisms on the GT-S models (rear disc brakes) tend to stick. I haven't experienced this myself, but check for it, anyway. First, check how many clicks the parking brake handle will make until the rear wheels are firmly held--this should be b/t 4-7 clicks. Then, jack up the rear end, fully release the parking brake, and spin the rear wheels by hand. If you notice a lot of resistance (like the parking brakes are still applied), have the mechanism checked out.
• Leaky Lights
  The rear taillight housings will usually leak with old age. If you park your car outside during a big rain storm, you may find a noticeable amount of water in the trunk which has soaked the trunk lining. The solution? Get yourself some clear caulking silicon from the local hardware store. Strip the rearmost lining in the trunk for a better view of the taillight housings. See the gap between the plastic housings and the sheetmetal? Plug it up nice and good with the caulk. If you got the clear caulking material, you'll be able to see if there's water seeping through any spots you may have missed.
• Lackluster Lighting
  Almost every Toyota owner I know of isn't happy w/ the interior lighting. Those w/ the "regular" grade AE92 models have it worse than most others--the instrument panel is flood lighted and isn't the best in the night. At least the GT-S model has back-lighted instruments. Dome lights? Heh, forget about it. Of particular note is the bulb that lights up the HVAC (heater controls) panel. It's a dinky bulb that seems to blow out if the car's old. I didn't even know that panel lit up when I first got my car. Then, I took a look in the owner's manual. =)
• Underbody Plugs MIA
  On that note, if you notice some water in the passenger compartment (rare, but not unheard of), jack up the car and check to see if all of the circular rubber plugs on the bottom of the car are still there. They're really for drainage purposes, but if they're not there, they'll be doing the opposite!
• Not-So-Variable Fan Speed
  If you find that not all of the fan speeds work on the ventilation system, the blower motor resistor is most likely burnt out. The part should cost around $25 or so. The resistor is located on the passenger's underdash area. Look for a module held by 2 Philips head screws on the blower motor case.
• Icky Idle
  A cold idle of 1800-2200 rpm is normal! But, if the temp. gauge is at normal operating temperature and the idle is still high, the auxilliary air bypass system may need to be cleaned and the cooling system bled. Also, check the idle stop screw, throttle body gasket, and ignition timing. If you have an idle that bounces between 1000-2000 rpm, you most likely have an air pocket in the cooling system. Bleed the system and the idle problem should disappear.
• Dripping Distributor
  The distributor on the 4A-GE engine is notorious (don't get me started!) for leaking oil after any of its 3 seals fails. You have 2 options: get a new distributor assembly from Toyota (expensive!) or try to take apart and rebuild the old distributor using some generic seals from a specialty automotive store.
• Bothersome Blinking A/C Light
  The A/C compressors (TV14C model) in the older Corollas seem to crap out all too easily. If your A/C light blinks a few seconds after you turn on the A/C, the A/C magnetic clutch pulley, compressor, or A/C ECU (Toyota calls it an "amplifier" for some reason) is suspect. While you're looking at the A/C pulley, have someone turn on the A/C. If you notice the pulley turning (even if it's jerky or doesn't seem to turn that much), the magnetic clutch pulley is fine. The compressor's bearings may have seized and won't allow the compressor to turn. Thankfully, Toyota engineered a compressor rpm safety switch that automatically disengages the magnetic clutch pulley in the event that the compressor doesn't make revolutions.
• Ditch the Dashpot
  Disable the dashpot system. Look at the throttle cam on the throttle body. See that plunger-looking thing that is touching the throttle cam? That's the dashpot. With age, the diaphragm valve inside will keep the throttle from fully closing. It'll make it seem like the engine's idling too high. All you have to do is loosen the lock nut, back down the screw until it doesn't touch the throttle cam, and then tighten the lock nut.
• Possible Rust Areas
  A friend in New Zealand did a serious cleaning on the exterior of his coupe and found some potential rust spots that are only accessible once the rear bumper cover is removed. Thanks, Cam!
• Dirty Throttle Body
  If the engine's idle is bad (bumpy, unsmooth, whatever), try pulling the throttle body, stripping it of the expensive parts (throttle position sensor, auxilliary air bypass, etc.) and cleaning it out using some strong detergent like undiluted Simple Green. Use a toothbrush and get the bore and butterfly valve cleaned as you care. Use compressed air to blow out the small air passages. Use a new T/B gasket when assembling.
• Sucky Synchros
  For some odd reason, Toyota didn't over-engineer the 2nd and 3rd gear synchros in the GT-S' manual tranny (designated C52). Also, the C52s are known for popping out of 5th gear (symptom of bad rear shaft bearings). If you plan on racing a lot, I'd recommend getting some C52 spares (they're available for around $200-300 at some reputable Japanese surplus importers). If you have spare money to burn, get it properly rebuilt (around $600-1200) so it'll hold up better during a hard season of racing. New C52 transaxles are available f/ Toyota for around $1800.
• Redline to the Rescue
  The gear shift quality in most AE92 GT-S's is known to be notchy, if not downright nasty. The solution? Drain the tranny fluid and fill it with some Redline MTL. If it's really bad, then use the MT90 which is a little bit thicker. Don't expect the shift quality to improve overnight... It took me around 2-3 months of running the MTL to smoothen out the shifts a little.