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CriticalCommonCooling

Toyota Yaris: G16E-GTS Cylinder Head Coolant Bridge Crack

G16E-GTS Cylinder Head Coolant Bridge Crack is a common cooling fault on the Toyota Yaris on the 2020–2023 cars, and we rate it critical. Putting it right costs $4,500 to $9,500 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 29 documented faults on the Toyota Yaris.

Vehicle
Toyota Yaris
Only on
GR Yaris / GR Corolla
Engine
G16E-GTS
Years
2020–2023
Fuel
petrol
Gearbox
manual
System
Cooling

This page covers the Toyota Yaris as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Toyota Yaris faults29 documented faults on this model

What you are looking at

A removed six-cylinder diesel engine cylinder head on cardboard, valve-gear side facing up.Example of the part — not this vehicle

A six-cylinder diesel head off the engine, valve-gear side up. Cracks run between the valve seats on the face beneath.

Ll1324 · CC0 · Wikimedia Commons

What goes wrong

The G16E-GTS 1.6T engine's cylinder head contains an internal coolant crossover bridge/gallery cast into the head that is prone to cracking under sustained thermal cycling and high-load operation. When the bridge fails, coolant migrates into the intake ports or combustion chambers, risking hydrolock or catastrophic overheating. Toyota acknowledged the defect and issued a Technical Service Bulletin requiring cylinder head inspection and replacement on affected units.

What you would notice

  • Unexplained coolant loss with no visible external leak
  • White or grey smoke from exhaust indicating coolant burning in combustion chamber
  • Milky or emulsified oil on dipstick or under oil filler cap
  • Coolant residue or crystalline deposits visible inside intake manifold
  • Engine overheating warning light illuminating under normal conditions

How to check it

Where to look. Engine cylinder head, internal coolant crossover gallery between water jacket passages

  1. Check coolant reservoir for oily contamination and the oil dipstick and filler cap underside for milky emulsified oil.

  2. Inspect inside the intake manifold for white crystalline residue indicating dried coolant.

  3. Request Toyota dealer service records confirming cylinder head TSB inspection or replacement was completed.

Parts involved: Cylinder head.

What it costs to put right

$4,500 to $9,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

  • “Has the cylinder head been inspected or replaced under the Toyota TSB for the G16E-GTS coolant bridge crack?”
  • “Has the car ever experienced a coolant loss event, low coolant warning, or overheating light?”
  • “Can you provide Toyota dealer documentation of any warranty or recall work performed on the engine head?”

Now check the Toyota Yaris you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Toyota Yaris buyer questions

Is g16e-gts cylinder head coolant bridge crack serious on a Toyota Yaris?

We rate it critical and common on the Toyota Yaris. The G16E-GTS 1.6T engine's cylinder head contains an internal coolant crossover bridge/gallery cast into the head that is prone to cracking under sustained thermal cycling and high-load operation. When the bridge fails, coolant migrates into the intake ports or combustion chambers, risking hydrolock or catastrophic overheating. Toyota acknowledged the defect and issued a Technical Service Bulletin requiring cylinder head inspection and replacement on affected units.

How much does it cost to fix on a Toyota Yaris?

$4,500 to $9,500 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Toyota Yaris years are affected?

Our research records this fault on the 2020–2023 Toyota Yaris. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Check coolant reservoir for oily contamination and the oil dipstick and filler cap underside for milky emulsified oil. Inspect inside the intake manifold for white crystalline residue indicating dried coolant. Request Toyota dealer service records confirming cylinder head TSB inspection or replacement was completed. Look here: Engine cylinder head, internal coolant crossover gallery between water jacket passages