Mitsubishi MTX13 & MTX15 faults: from starting problems to a lift that won’t lower
Does your Mitsubishi MTX15 not start, does the starter motor stay silent, or does the engine immediately stall again? The original manual for the Mitsubishi MTX13D and MTX15D contains complete fault tables, and in this article we've translated them all into clear symptom-cause-solution tables per system. Supplemented with the most well-known practical issues of this series, so you can search with purpose instead of guessing.
Suitable for the entire series: Mitsubishi MTX13D and MTX15D.
Mitsubishi MTX13 & MTX15 starting problems
| Symptom | Possible cause | Solution |
|---|---|---|
| Starter motor doesn't turn | Clutch pedal not fully depressed (starter safety interlock!); flat battery; loose or corroded battery terminals; defective switch or starter motor | Fully depress the clutch; charge the battery; clean and tighten the terminals; test the switch/starter motor |
| Starter motor turns slowly | Weak battery; poor ground connection; engine oil too thick for the temperature | Charge or replace the battery; check the ground cable; use winter oil (10W-30) |
| Engine won't catch | Empty tank; air in the fuel system; clogged fuel filter; fuel tap closed | Refuel; bleed the system; replace the filter; open the tap |
| Engine starts but stops immediately | Oil level too low (oil pressure safety cut-off engages) | Check the oil level and top up |
The complete starting procedure — including the clutch starter safety interlock and preheating — can be found in our article about operating and starting the MTX13 and MTX15.
Mitsubishi MTX13 & MTX15 runs irregularly or loses power
| Symptom | Possible cause | Solution |
|---|---|---|
| Running irregularly | Air or water in the fuel; contaminated injectors; leaking lines | Bleed and add fresh diesel; have the injectors cleaned; replace the lines |
| Engine stops suddenly | Out of fuel; oil pressure safety cut-off (oil level!); fuse or fusible link | Refuel and bleed; check the oil level; check fuses and fusible link 1025 3543 000 (for reference, verify by serial number) |
| White exhaust smoke | Too much engine oil; fuel supply not in order | Correct the oil level; check the fuel system |
| Black exhaust smoke | Air filter clogged; wrong fuel; defective injector | Clean or replace the air filter; refuel with the correct diesel; have the injector tested |
| Power loss | Injectors contaminated/carbon build-up; compression; valve clearance; fuel filter; air filter | Replace filters; have a specialist adjust the valve clearance (0.25 mm) and injector pressure (140 kg/cm²) every 200 hours |
Many of these complaints start with contaminated filters; in our overview of all filters for the MTX13 and MTX15 you can see exactly which ones are fitted on the machine.
Mitsubishi MTX13 & MTX15 warning lights and overheating
| Symptom | Possible cause | Solution |
|---|---|---|
| Oil pressure light stays on while running | Oil level too low; wrong (too thin) oil; oil filter clogged; pressure switch defective | Stop immediately; correct the level and oil type; replace the oil filter; test the pressure switch |
| Charge light stays on | V-belt loose or broken; wiring; alternator defective | Tension the V-belt (deflection 10–13 mm) or replace it — V-belt MD017016 (for reference, verify by serial number); check the wiring and alternator |
| Overheating | Coolant level too low; V-belt slack; radiator core contaminated | Top up the coolant; tension the belt; clean the radiator core every 50 hours |
Mitsubishi MTX13 & MTX15 engine won't stop with the key
A typical quirk of this series: the engine is stopped by an electric stop solenoid. If it doesn't work, the engine simply keeps running after you turn the key to OFF.
| Symptom | Possible cause | Solution |
|---|---|---|
| Engine won't stop with the key | Flat battery (solenoid gets no power); key timer relay defective; fuse C; fusible link | Open the right side cover and press the solenoid switch by hand; then check the battery, relay, fuse C, and fusible link |
Mitsubishi MTX13 & MTX15 clutch, brakes, and steering
| Symptom | Possible cause | Solution |
|---|---|---|
| Clutch slips | Pedal play too small; lining worn | Adjust the play to 20–30 mm; replace the lining |
| Clutch doesn't disengage | Play too large; lining stuck (after long storage) | Adjust the play; free the stuck plate |
| Brakes poor or one-sided | Play too large; left-right unevenly adjusted; lining worn | Adjust brake pedal play to 40–50 mm and set left = right; replace the lining |
| Brake pedal returns poorly | Return spring; lubrication points dry | Replace the spring; lubricate the grease points (every 50 hours) |
| Heavy steering | Toe-in incorrect; uneven tyre pressure; play in tie rod ends | Set toe-in to 0–5 mm; tyres to 1.2 (front) / 1.0 (rear) bar; replace the tie rod ends |
Mitsubishi MTX13 & MTX15 hydraulic faults: lift doesn't raise or lower
| Symptom | Possible cause | Solution |
|---|---|---|
| Lift doesn't raise | Transmission oil level too low; air in the suction line; hydraulic filter clogged; pump or valve defective | Top up the oil level; check the suction side; replace hydraulic filter 1135 2452 000 (for reference, verify by serial number); have the pump/valve tested |
| Lift doesn't lower | Lowering speed knob is in the locked position (fully clockwise); valve defective | Turn the knob counterclockwise to open it — this is the most common "fault" that isn't actually one; otherwise check the valve |
| Squealing noise when lifting above the stop | Relief valve blowing off (stopper/feedback incorrectly adjusted) | Have the stopper/feedback adjusted |
| Strange noise from the hydraulics | Oil level too low; cavitation due to clogged filter | Top up the level; replace the hydraulic filter |
Remember: the transmission and hydraulics share one 12-litre housing. Wrong or contaminated oil therefore directly causes lift problems — the correct oil recommendation is in our guide on engine oil and fluids.
Mitsubishi MTX13 & MTX15 known practical issues
In addition to the manual's tables, these are, from practical experience and owner feedback, the most well-known weak points of older machines:
- Difficult cold starting: aged glow plugs or too short a glow time are a classic with this engine family. Glow plugs are inexpensive and available individually: Glow plug L3A/L3C (SKU-559014).
- Leaking water pump: with age, the pump starts dripping from the shaft (weep hole). Replace including gasket: Water pump MTX13/MTX15 incl. gasket (SKU-337).
- Sticking thermostat: the engine runs too cold or too hot. Solution: Thermostat 76.5°C incl. gasket (SKU-45001).
- Stop solenoid or key timer relay defective: the engine no longer stops via the key — see the table above.
- After years standing outside: stuck clutch and seized brake anchors.
- Rust and dirt in old fuel tanks: repeatedly clogged fuel filters until the tank itself has been cleaned.
- Transmission leak due to dried-out seals: an additive such as Gearbox leak-stop 250ml (SKU-125004) can help, otherwise replace the seals.
🔧 The most requested parts for faults
For the most common complaints with this series, we have the parts in stock: the Glow plug L3A/L3C (SKU-559014) for starting problems, the Water pump MTX13/MTX15 incl. gasket (SKU-337) and the Thermostat 76.5°C incl. gasket (SKU-45001) for cooling problems, and the Filter set MTX13/MTX15 (SKU-100119) for smoke, power loss, and fuel complaints.
