Frequently Asked Questions
In this page is the basic information on the car, maintenance, and background regarding the Celica All Trac. If you are interested in learning how to modify your All Trac, click here for the Modifications FAQ.
About The Celica All
- What To Look For When Purchasing
- Check Engine Light
- How To Perform Maintenance
- How To Troubleshoot Problems
- Toyota Part Numbers
Way back in 1972, Toyota decided to start competing in rally races. Since then Toyota has made much success modifying their baseline cars to compete in events through the years from then until now. In 1975 Toyota Team Europe (TTE) was created to concentrate full time on the racing effort. They took their first big win that year with a Toyota Corolla. In the later part of the 70's TTE moved to the Celica platform to use as their race cars. In 1987, Toyota moved to a bigger facility and showed off their new 4wd Celica. In order for a car to be used in rally racing it had a be a production car; thus, a certain number must be made and sold to the public. So in 1987, the Toyota GT-Four was up for sale. A race car was built and was sold for the sole purpose of racing. There was a lot of details in the design and it shows. In 1988, the GT-Four was imported to the USA under the name Celica All Trac.
The first version of the All Trac is known as a ST165 (87-89). The ST165 was based on the ST162 (naturally aspirated front wheel drive) Celica but with several unique changes. Most notably was the drivetrain that was a full time all wheel drive system. The engine was replaced the natural aspirated one with a 16 valve, 2.0 liter motor that was turbo charged and top mounted water-to-air intercooled. This created a performance oriented engine that had a base of 185 horsepower. The performance was close to it's big brother, the Toyota Supra Turbo. However, the All Trac was popular because could take advantage of the all wheel drive during the winter and extreme weather conditions. The car was not a big seller, but it was not Toyota's intention to sell a lot of All Tracs because the car had been built for competition in rally campaigns. An updated version of the ST165 was released in 1989 that accommodated new designs to the interior. To name a few options were power windows, power sunroof, power locks, power and heated mirrors, and an optional leather interior among other things. Around the time of the last ST165s were being sold, a new body style and update of the GT-Four was being produced in Japan (10/89).
For 1990 a newly redesigned Celica (ST182) was to be introduced. This of course meant a newly designed Celica All Trac (90-93). The production started in Japan using the newly designed Celica platform. This platform came with a wider body and larger wheels with other changes that were added. This how the second generation Celica All Trac (ST185) came to be. This was radically more stylish car than it's predecessor, the old ST165. Replacing the old boxy style of the 80's was a sleeker, cleaner, and more aero dynamic look with a more attractive body style. The ST185 had the AWD system put in and it had a new dual entry turbo charged, air-to-air intercooler system that was also placed on top of the engine. An air scoop was made in the hood so air would be forced onto the intercooler while the car is in motion. Vents were also integrated into the side of the hood to let hot air escape from the engine bay. The compression was also bumped up and low end power was regained. The overall output was 200 hp and 200 pounds of torque. Toyota continued to import the All Trac to the USA through 1993. Also in Japan and other export countries the ST185 RC or "Carlos Sainz" edition was released. It had a better and more aggressively tuned ECU with a more efficient reverse hood scoop design that cooled the alternator and let hot air vent out. Replacing the air-to-air intercooler was a very efficient water-to-air intercooler system. This setup made out with a great victory in the rally championships. In 1993, due to dying interest, and low export from Japan, only 81 US All Tracs (ST185) were sold. This is where the All Trac story ends.
In Japan and other export countries starting in 1994, the ST205 was on produced and sold. This was Toyota's latest rally powerhouse. This was based on their newest Celica platform with many more enhancements. It sported a redesigned head, intake and exhaust manifolds. A larger more efficient turbo was fitted along with a new powerful ECU system and better fueling. The power rating was bumped up to 225 hp. This also had the water-to-air intercooler and reverse scoop design. The suspension system was updated along with a new braking system and new 16" size rims. Still considered quick by today's standards, and the holy grail of any GT-Four or All Trac fan. A special WRC model was also made available with yet a few more rally enhancements. After a few years of production, Toyota bid farewell to it's performance model GT-Fours and Supra Twin Turbos in favor of cleaner, more environmentally friendlier cars. Rumors exist as to the return of the performance super car from Toyota. We can only wait.
In summary, here are the vehicle codes that we in our club use most:
ST165 - 88-89 Celica All Trac Turbo (US), 87-89 GT-Four (Japan)
ST185 - 90-93 Celica All Trac Turbo (US), 90-93 GT-Four (Japan)
ST205 - 94-99 GT-Four (Japan)
See our inspection page.
See our Check Engine page.
See our Maintenance Articles page.
We are keeping a list of the most common part numbers associated with routing maintenance. Since a lot of parts are available only at Toyota, we have only Toyota part numbers listed. Another page will come that contains some aftermarket "acceptable" replacements. However, in most cases Toyota parts are of the highest quality.
What capacity and fluid types to use? Here is what is recommended by the TSRM:
Oil Change - API Grade SF
- Drain and Fill w/ Oil Filter Change 3.8 Quarts
- Drain and Fill w/o Oil Filter Change 3.6 Quarts
- Dry Fill 4.9 Quarts
Transmission Gear Oil - API GL-5
- SAE 75W-90 or 80W-90
- 5.1 Quarts (4.8 liters)
Rear Differential - Hypoid API GL-5
- SAE 90
- 1.2 Quarts (1.1 liters)
- Capacity w/ Heater (8.0 liters)
- Intercooler capacity (1.7 liters)
Depending on where you lived, you received a re-named named GT-four.
USA - Celica Turbo All Trac
Japan - Celica GT-four, Celica GT-four RC, Celica GT-four WRC
UK - Celica Turbo 4wd, Celica Carlos Sainz Limited
AUS - Celica GT-four, Celica GT-four Group A Rallye
The number of GT-fours actually made is a bit of a mystery.
Here are the claims of production by Toyota:
(10/86-09/89) ST165 - 26,500
(09/89-08/93) ST185 - 26,000 (5,000 RC Model)
(00/00-05/99) ST205 - 00,000 (2,500 WRC Model)
Here are the number of GT-fours that were exported from Japan.
9,000 - Europe
2,500 - North America
2,500 - Australia and New Zealand
1,000 - Other
Here are a few websites to search for your own All Trac:
www.autotrader.com - nationwide search
www.cars.com - yet another nationwide search but from newspapers
Ben's Rally Page - Rally or rally to be...
Craig's List - Bay Area as well as other city searches
As well as our own chat board, where users can post their All Trac/GT-four for sale:
These are terms you will see All Trac or Gt-Four owners use in common discussion. This way you will have an idea of what they are talking about.
VSV = Vacuum Switching Valve. This is the unit that will limit your boost in certain conditions. Under normal situations the boost pressure from your turbo is bled away from the wastegate (boost control device) causing a higher boost pressure of about 8 psi. Under conditions such as cold weather or some other situation where full boost should not be attained, the VSV closes. This forces all the boost pressure to the wastegate. This will make the wastegate open earlier and cause you to run about 5 psi until conditions improve. This device should be disabled when used with an electronic boost controller.
TVIS = Toyota Variable Induction System. This system debuted in earlier Toyota MR2 and corolla. Instead of the normal 4 intake runners of an intake manifold, this manifold contains 8 runners. In between the manifold and the head itself, there is a plate in which 4 of the 8 runners have a flapper door than can be opened and closed as needed. Under normal cruising conditions 4 of these 8 runners are sealed, forcing all the air through the 4 small air ports. When the RPM reaches 4300 RPM, or the throttle is fully pressed (WOT), the flappers will open allowing all 8 ports to be open. This will create the effect of 4 large intake ports and thus open the door to higher performance upper end while maintaining low end responsiveness.
Cat Gut = Removing the internals of the catalytic converter. This is one of the first mods performed by All Trac owners. This involves removing the primary catalytic converter and punching out all the material until it is completely empty. This low buck mod is worth about 8-9 HP and is free. This of course effects emissions and is not legal. Some owners have reporting passing smog even with this mod performed.
AFM = Air flow meter. This is the air metering device that measures the air flow into the engine. There is a "flap" that moves against spring resistance as air enters the engine. The more the flap moves away from it's original position, the more air flow is entering the intake system. Based on this figure, the ECU determines what fueling and timing figures to use for combustion.
The Toyota ECU (computer) has a built in protection to keep the turbo from preventing damage to the motor in the case of an over boost. An over boost would be when the turbo pressure limiting system failed, causing the turbo to start making unlimited boost. If this were allowed to continue, your motor would shortly be broken. The Toyota ECU uses a pressure sensor to detect maximum boost. Maximum boost in this case is 12 psi for ST165 and ST185, and 17 psi for ST185RC/ST205. If this amount is detected, the fuel will stop being sprayed into the engine momentarily to prevent further combustion. When driving this appears to be a sudden loss of power, causing you to fly towards the dash. It is almost the same effect as slamming on the brakes. In some cases the check engine light will flash as well, until the car is turned off. This is a good safety feature, but if you are trying to run higher boost on purpose, it can be a road block. There are several devices available to remove this fuel cut (or raise it to a higher level). See the Modifications FAQ for more information.
This is positive crankcase ventilation. While most cars have a valve that controls this process, ours do not. The crankcase oil vapors are vented from the valve cover via a metal tube. The gases are sucked into the intake piping after the AFM using the vacuum created by the running engine. Many choose to disable this process, as once boost is raised the oil vapors collect rapidly in the intake piping and the internal passages of the intercooler.
Comments:John O Gorman (9/2/2014)
I recently acquired a 1991 ST185, the car is a Japanese import to Ireland and I only paid 350 euro for it intentions of using it as a donor yet I've noticed that the car was resprayed some time ago to gray metallic from its original Burgundy Pearl Red Metallic 3H4 and I'm wondering was there many 1991 cars produced in that colour from the factory. As I've been led to believe that the GT4 was only sold in this particular colour for about one year. Thank you for your help.
chris edmondson (12/26/2011)
i have a st205 but have a prob. the boost gage is always going up wen u dont hit the turbo an its down on power.?? can u help. had all turbo stript an that but no good