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CriticalCommonEngine

Mitsubishi Colt: 4G15T Turbo Oil Return Pipe Blockage Causing Turbocharger Failure

4G15T Turbo Oil Return Pipe Blockage Causing Turbocharger Failure is a common engine fault on the Mitsubishi Colt on the 2006–2012 cars, and we rate it critical. Putting it right costs $800 to $2,800 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 10 documented faults on the Mitsubishi Colt.

Vehicle
Mitsubishi Colt
Engine
4G15-T
Years
2006–2012
Fuel
petrol
System
Engine

This page covers the Mitsubishi Colt 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 Colt faults10 documented faults on this model

What you are looking at

No photograph available

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

What goes wrong

The turbocharger oil drain (return) pipe on the 4G15T Ralliart engine is prone to internal carbon and sludge accumulation, progressively restricting oil flow back to the sump. Restricted drainage causes oil to pool in the turbocharger centre section, overwhelming the shaft seals and forcing lubricant into both the compressor and turbine housings, accelerating bearing wear and ultimately causing turbocharger seizure if the pipe is not periodically cleaned or replaced.

What you would notice

  • Blue-grey smoke from exhaust under acceleration or on deceleration/overrun
  • Excessive engine oil consumption with no visible external leaks
  • Turbocharger whine, rattle, or rumble at boost
  • Oil contamination visible inside intercooler or intake piping

How to check it

Where to look. Turbocharger oil return pipe routes from the base of the turbocharger centre housing down to the engine block sump connection on the left side of the 4G15T engine bay.

Watch for: Blue-grey smoke from exhaust under acceleration or on deceleration/overrun. If a workshop inspection is possible: Remove the turbocharger oil return pipe and inspect the bore internally for sludge or carbon restriction; check engine oil level and condition for depletion or contamination; inspect the intercooler core and inlet ducting for oily deposits indicating seal bypass; check for radial or axial play in the turbocharger shaft by hand.

Parts involved: Turbocharger.

What it costs to put right

$800 to $2,800 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 turbocharger oil return pipe ever been inspected, cleaned, or replaced?”
  • “What is the oil change interval and has the oil consumption been monitored?”
  • “Is there any visible oil in the intercooler or intake hoses?”

Now check the Mitsubishi Colt 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 Colt buyer questions

Is 4g15t turbo oil return pipe blockage causing turbocharger failure serious on a Mitsubishi Colt?

We rate it critical and common on the Mitsubishi Colt. The turbocharger oil drain (return) pipe on the 4G15T Ralliart engine is prone to internal carbon and sludge accumulation, progressively restricting oil flow back to the sump. Restricted drainage causes oil to pool in the turbocharger centre section, overwhelming the shaft seals and forcing lubricant into both the compressor and turbine housings, accelerating bearing wear and ultimately causing turbocharger seizure if the pipe is not periodically cleaned or replaced.

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

$800 to $2,800 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 Colt years are affected?

Our research records this fault on the 2006–2012 Mitsubishi Colt. 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?

Watch for: Blue-grey smoke from exhaust under acceleration or on deceleration/overrun. If a workshop inspection is possible: Remove the turbocharger oil return pipe and inspect the bore internally for sludge or carbon restriction; check engine oil level and condition for depletion or contamination; inspect the intercooler core and inlet ducting for oily deposits indicating seal bypass; check for radial or axial play in the turbocharger shaft by hand. Look here: Turbocharger oil return pipe routes from the base of the turbocharger centre housing down to the engine block sump connection on the left side of the 4G15T engine bay.