CriticalCommonEngine

Mitsubishi Galant: 6A12/6A13 V6 Timing Belt Tensioner & Idler Failure

6A12/6A13 V6 Timing Belt Tensioner & Idler Failure is a common engine fault on the Mitsubishi Galant on the 1996–2004 cars, and we rate it critical. Putting it right costs $650 to $1,400 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 13 documented faults on the Mitsubishi Galant.

Vehicle: Mitsubishi Galant
Engine: 6A12 / 6A13
Years: 1996–2004
Fuel: petrol
System: Engine

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

All Mitsubishi Galant faults13 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Timing belt yet. We would rather show none than show a picture of a different part.

What goes wrong

The 6A12 2.0L and 6A13 2.5L DOHC V6 engines use a hydraulic auto-tensioner with spring-loaded damper and two idler pulleys on a long dual-overhead-cam belt path. The tensioner hydraulic cartridge seals degrade with age, losing damping pressure and allowing belt flutter. Idler bearings develop roughness from heat cycling and contaminated oil vapour ingress. The 6A13TT twin-turbo configuration is a fully interference engine — piston-to-valve contact occurs on belt failure. Factory service interval is 100,000 km but NZ/AU imports frequently have unverified Japanese service histories, making tensioner and idler bearing failure the primary catastrophic risk on these engines. Turbo heat soak in 6A13TT applications accelerates idler bearing grease breakdown beyond the naturally aspirated rate.

What you would notice

High-pitched ticking or chirping from front of engine at idle
Squealing from behind timing belt cover on cold start
Rough running or misfires if belt has jumped a tooth on interference variant
Sudden engine stall with no restart on complete belt failure

How to check it

Where to look. Front of engine block behind plastic timing belt covers; partially accessible from the passenger-side wheel arch after removing the inner guard

Spin both idler pulleys by hand and feel for any roughness, notchiness or axial play indicating bearing wear. Check tensioner rod extension length against spec — a fully collapsed rod indicates loss of hydraulic pressure. Inspect water pump weep hole while covers are off. If a workshop inspection is possible: Remove the upper timing belt cover and inspect belt surface for cracking, glazing, fraying or contamination.

Parts involved: Timing belt.

What it costs to put right

$650 to $1,400 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

“When was the timing belt last replaced and do you have receipts?”
“Were both idler pulleys and the tensioner replaced at the same service?”
“Was the water pump also replaced at the last belt change?”

Now check the Mitsubishi Galant 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.

Mitsubishi Galant buyer questions

Is 6a12/6a13 v6 timing belt tensioner & idler failure serious on a Mitsubishi Galant?

We rate it critical and common on the Mitsubishi Galant. The 6A12 2.0L and 6A13 2.5L DOHC V6 engines use a hydraulic auto-tensioner with spring-loaded damper and two idler pulleys on a long dual-overhead-cam belt path. The tensioner hydraulic cartridge seals degrade with age, losing damping pressure and allowing belt flutter. Idler bearings develop roughness from heat cycling and contaminated oil vapour ingress. The 6A13TT twin-turbo configuration is a fully interference engine — piston-to-valve contact occurs on belt failure. Factory service interval is 100,000 km but NZ/AU imports frequently have unverified Japanese service histories, making tensioner and idler bearing failure the primary catastrophic risk on these engines. Turbo heat soak in 6A13TT applications accelerates idler bearing grease breakdown beyond the naturally aspirated rate.

How much does it cost to fix on a Mitsubishi Galant?

$650 to $1,400 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 Mitsubishi Galant years are affected?

Our research records this fault on the 1996–2004 Mitsubishi Galant. 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.