Ultimate Toyota 3S-GTE Engine Guide

Toyota’s 3S-GTE engine is a 2.0L inline-4 that was used in the MR2 and Celica cars from the late 80’s until the late 2000’s. It came with a turbocharger from the factory, making it a popular engine for performance modifications. And barring a few problems, it can make some pretty good power with performance upgrades.

The 3S-GTE is known to have a few problems with the blocks cracking, oil leaks, and turbocharger failure, all of which become even more likely when modified. In this guide we’re going to cover everything about this engine, with a main focus on performance and reliability. We’ll cover engine specs and then jump into some of the best performance upgrades, common problems, and how performance mods impact overall reliability.

Cars It’s Used In

• 1986-1989 Toyota Celica ST165 (1st gen engine)
• 1990-1993 Toyota Celica ST185 (2nd gen engine)
• 1990-1993 Toyota MR2 (2nd gen engine)
• 1994-1999 Toyota Celica ST205 (3rd gen engine)
• 1994-1999 Toyota MR2 (3rd gen engine)
• 1997-2001 Toyota Caldina ST215 (4th gen engine)
• 2002-2007 Toyota Caldina ST246 (5th gen engine)

3SGTE Engine Specs

Engine	Toyota 3S-GTE
Configuration	Inline-4
Displacement	1,998cc (2.0L)
Aspiration	Turbocharged
Block Material	Cast Iron
Head Material	Aluminum
Valvetrain	DOHC, 16 valves
Bore x Stroke	86mm x 86mm
Compression Ratio	8.5 : 1 to 9.0 : 1
Horsepower	182-256 HP
Torque (lb-ft)	184-239 TQ

The 3S-GTE is a 2.0L inline-4 turbocharged engine. It uses a heavy cast iron block which provides excellent strength. Cylinder heads are made from aluminum in order to keep weight lower. Toyota went with a DOHC 16 valve design, which is standard for many of their engines.

A square engine with equal bore and stroke provides a good balance of power and torque. Depending on generation the 3SGTE features a different compression ratio. 1st and 3rd gen engines are 8.5:1 compression. The 2nd gen engine has an 8.8:1 compression ratio while later 4th and 5th gen engines are 9.0:1.

Add up all of the specs and its good for 182 to 256 horsepower and 184-239 lb-ft. Power consistently increased with each new generation of the 2.0 inline-4 turbo. 1st gen engines offer 182-190 horsepower while all following generations come in at 200+ horsepower and 200+ torque.

Engine Generations

All of the 3SGTE generations share the same basic engine design and specs from above. However, there were a number of updates to help improve power, performance, and reliability over the years. It would be impossible to cover all of the details and differences for each engine. As such, we will simply provide a quick breakdown of notable changes over the years.

• 1st Gen: 8.5:1 compression ratio and 8-9 PSI boost on the turbo. Air to water intercooler
• 2nd Gen: Increase to 8.8:1 compression and 10-11 PSI. Twin entry turbine housing with dual wastegate ports. Switch to air-to-air intercooler
• 3rd Gen: CT20B turbo. Similar design to 2nd gen with larger compressor wheel. Boost increases to 13 PSI. Switch back to air-to-water intercooler. Air flow meter replaced with MAP sensor. Larger fuel injectors. Engine block revised in 1997 to prevent cracking issues.
• 4th Gen: CT15B turbo. Exhaust housing is cast to the manifold. Air-to-air top mount intercooler. Larger 550cc fuel injectors. Compression increase to 9.0:1.
• 5th Gen: Longer injectors lie closer to intake ports. Slightly smaller air-to-air intercooler. Ignition system updates. New valve cover design. Oil cooler removed.

As the generations progress the updates help improve horsepower and torque. There were some interesting updates on the 5th gen engine that seem like downgrades. However, the engine still offers the same 256 horsepower output as the 4th gen engines.

Those looking to swap a 3S-GTE engine will likely find the 3rd and 4th gen engines to be the most capable. Unfortunately, the 4th engine was only in the Toyota Caldina which was not available in US markets (as with the 5th gen engine, too).

Toyota 3S-GTE Performance

Performance of the stock 3S-GTE Toyota Celica and MR2 isn’t our main focus here. We won’t dive into specific performance metrics. 0-60, 1/4 mile, and other performance measures vary too much. Of course, in general the later engines are faster from the factory. Power consistently increased over the years.

The 2.0L turbo engine is very capable from the factory. For its era the 3SGTE engine offers great performance. However, the engines strength is what makes them so desirable. A cast iron block and strong internals mean the engine has plenty of potential on the table. Basic tuning and bolt-on mods can take the engine to the next level.

Performance Upgrades & Mods

We’ve got a full guide on 3SGTE performance upgrades, so check that out if you want to really dig in. Here, we are going to cover some of the most popular performance mods that people do for Stage 1-3 builds, at a high level. We touch on all of these in our mod guide linked above.

Stage 1: (200-225whp)

• Exhaust / Downpipe
• Intake
• Boost controller
• Fuel cut defeat

To make more power on a turbo engine it’s important to help air-flow in and out of the engine. This means an exhaust and intake are great mods to support more power and boost. You want to modify to part of the exhaust nearest the turbo; this is known as the downpipe.

Next you simply need a manual or electronic boost controller. This will allow the engine to run about 14-16 PSI with the assistance of a fuel cut defenser. These simple mods can take the Toyota 3S-GTE engine to 200+whp. All in all, this can be done for less than $1,000 and even less than $500 if you’re resourceful.

Stage 2: (250-275+whp)

To shoot beyond 250whp you’ll want all of the Stage 1 upgrades plus a few extra things:

• Stage 1 mods
• Turbo upgrade
• Intercooler upgrade
• Fuel system upgrades

At this point you’ll need a turbo upgrade unless you have the CT20B turbo in the 4th gen engine. Next you should address cooling with an intercooler upgrade.

The stock fuel system can support about 260-280whp, so fueling mods are a good idea. If you’re keeping the stock fueling it’s important to keep an eye on AFR readings. Once you’re at the fueling limits it’s time to upgrade.

Stage 3 & Above: (300-350+whp)

Now we’re starting to get into much more expensive upgrades. 300+whp on a Toyota MR2 or Celica is no joke, though. If you’re willing to spend the money these are awesome setups. Here is what you’ll need:

• All stage 1 & 2 mods
• Engine management system (ECU)
• Clutch upgrades

The above is a minimum list of upgrades to make 300+whp. At this point you’re well beyond the stock fueling limits. You’ll need a fuel pump, injectors, and a larger turbo as the foundation to make power.

It’s also important you have control over all 3S-GTE engine and tuning parameters. This means upgrading the engine management system and working with a professional tuner to dial in a good tune. Depending on how far you want to take the MR2 or Celica the list of mods can grow very lengthy and expensive.

Common 3S-GTE Engine Problems

• Engine block
• Oil leaks
• Turbocharger

1) Cracked Engine Blocks

Engine blocks cracking is an interesting topic for the Toyota 3S-GTE engine. It uses a cast iron block. A design that’s often desired for the impressive strength of cast iron. However, engine blocks cracking is a hot topic. It’s most common on early gen 3 engines before 1997, but blocks cracking can happen on any 3S engine.

It appears the primary issues lies between cylinders number 2 and 3. The block is prone to cracking in that area due to thin casting. Toyota did beef up the block, so later engines are less prone to issues. Additionally, 3S-GTE engine blocks rarely crack on totally stock engines. It often occurs on modded engines due to higher cylinder pressures.

Anyways, this isn’t much of a common problem as it primary affects 3rd gen 3SGTE engines. It’s also rare on stock engines, so the main concern is those planning to mod and upgrade the engine. Regardless, Toyota blocks cracking is a serious issue that requires a new engine so it’s worth the mention.

*Cracked blocks are most common on 3S-GTE engines making 500+whp. If you’re planning to push the engine that far it’s a good idea to sleeve the block.

2) Oil Leak Problems

Next up are oil leak problems on the Toyota 3S-GTE engine. Oil leaks aren’t really due to any design flaws or other failures. All engines use many gaskets, seals, etc that are prone to degrading over time. Therefore, oil leaks are more of an age and mileage issue than anything else.

Rubber-like parts simply degrade with age and mileage. These gaskets and seals become brittle with age, begin cracking, and oil leaks occur. A few common areas for oil leaks include the main seals, oil pan, and valve cover gasket.

It’s normal for oil leaks to develop on many engines after 10+ years and 100,000+ miles. Don’t be fooled by low mileage examples since age can be just as hard on gaskets and seals. Point is – all Toyota 3S-GTE engines are beyond the age where oil leaks become commonplace. They’re usually cheap repairs, though. It’s especially true for the DIY crowd.

3) Turbo Failures

Last but not least – turbocharger issues on the Toyota 3S-GTE engine. We’ll be fairly quick on this topic since the turbos are actually pretty reliable. However, they are wear and tear parts that take a lot of abuse over the years. It’s especially true since the 3SGTE engine is so easy to upgrade and modify.

Anyways, turbo failures are mostly an age related issues. Most of these engines on the road today are 20+ years old, which is a long time for a turbo to be on the road. Chances are many previously modded 3S-GTE engines already have a new turbo. It’s also a good excuse to upgrade if your turbo does ever fail.

Toyota 3S-GTE Reliability

Is the Toyota 3S-GTE engine reliable? Yes, we believe this engine earns above average remarks for reliability. Turbo engines haven’t earned the best reputation for reliability or longevity. That’s especially true back in the 1980’s and 1990’s. However, Toyota did an excellent job with their 3S-GTE engine. It doesn’t suffer from many major design flaws with the exception of the gen 3 engine block.

Be cautious of blocks cracking on 3S-GTE engines, especially when modding and upgrading the engine. Otherwise, oil leaks and turbo failures are common issues. They’re mostly age related problems rather than any inherent problems or flaws, though.

A lot of reliability comes down to maintenance. Use high quality synthetic oils, change fluids on time, and fix problems if and when they occur. With proper maintenance it’s not uncommon for the Toyota 3S-GTE to make it beyond 250,000 miles. There are even highly upgraded engines that make it to that mileage with few issues along the way.