Potential faults on the Mitsubishi Colt 2.8 tdi

Engine Head and Overheating

According to leisurewheels, the tough and reliable Colt 4×4 was introduced in South Africa in 1997 and was only available in a three-litre V6 petrol engine (with its 109 kW and 234 Nm torque). At the end of 1998, Colt introduced an upgraded version with its new three-litre V6 petrol engine (and its 133 kW and 255 Nm of torque). Colt did not only stick to the three-litre V6 engine, they also introduced a 2.4 litre petrol engine 4×4 and later the more economical and very popular five speed, 2.8 litre four-cylinder turbo diesel (with its 92 kW and 294 Nm torque engine). In the period that the Mitsubishi Colt (known in Australia as the Mitsubishi Triton) was available in South Africa (1997 – 2008) it surely made a name for itself. In this article we will place our focus on this third generation 2.8 tdi, specifically with regard to the main issues related to it.

Why do we do this? Steves Auto Clinic, as a leading automotive repair and service franchise in South Africa, strive towards sharing experiences of vehicle owners among each other. It is better to embrace the philosophy of preventing issues beforehand by fixing small things before they turn into bigger things! In order to act preventatively, we need to be aware. Knowledge is a weapon just as ignorance is an enemy. Before we discuss the issues and start sharing experiences here, we have to make it clear that these views and experiences are not that of the Steves Auto Clinic group, they are the experiences of Mitsubishi Colt 2.8 owners and/or experts on these models. We also acknowledge the fact that one swallow does not make a summer, that is, one instance of an event does not necessarily indicate a trend, that is why we at Steves Auto Clinic in no way ascribe any of the discussed issues here as general and sure faults, i.e., as trends. We believe that by creating awareness of these issues, we empower you to detect issues early and address them effectively.

Let us therefore have a look at the main issues identified with the Mitsubishi Colt 2.8 tdi.

Possible Issues

2.8 tdi Engine Head

In a topic raised in a 4x4community (2008) forum regarding the acquisition of a second-hand 2.8 tdi, the question was asked whether such an acquisition was a matter of a HOT or a NOT deal. This is an open question, but I think the answer can be found in the “head”! In the head? Yes, but not in your head, in the engine’s head… The question many asked, and the issue many raised, was mostly related to the engine head. The matter of head issues was also raised in a 4x4community (2015) forum. From these forums, a few important aspects became known that should be kept in mind when it comes to discussing the issue of engine heads.

The first thing to understand is that head problems with the 2.8 tdi is not necessarily year-specific; you may argue that it is prevalent only in pre 2003 models, but every year of the 2.8 tdi model will be susceptible to head problems IF not driven correctly. Heads crack because of overheating (we will discuss overheating next), and this was apparently a common occurrence with all the first diesel bakkies. If this was so, then why? The first answer lies in the fact that any diesel engine with an aluminium head and pre-combustion chambers may experience head problems when overheating. The pre-combustion chamber is made of steel and it is pressed into an aluminium casting; because they expand differently when hot, they are susceptible to cracks.

The second reason is that most diesel engines do not like high revs and that they are sensitive to heat. An owner of a 2006 Mitsubishi 2.8 tdi, who clocked more than 180 000 km on the odometer, and never revved it higher than 3000 rpm, said that he never had a single problem with his 2.8 tdi. Another owner confirmed this driving style when he found that going over 3000 rpm was a waste and going below 2100 was dangerous for exhaust gas temperature (EGT) on deep throttle. If the road demands more power, it was suggested to change to a lower gear and keep the rpm around 2750. This was also confirmed in another 4x4community (2012) forum, where an owner of a 2.8 tdi who’s vehicle had more than 280 000 km on the odometer, said that his bakkie was much happier at 2500 – 2650 r/min than it was at 3000 r/min or above.

High exhaust gas temperatures will contribute to a cracked head, and it is argued that high EGT is caused by over-fuelling. This happens because of driving the torque, so to speak, and of using low revs and deep throttle. If this happens, the turbo fails to spool fast enough (at low revs) while your throttle have a high demand, hence the over-fuelling and the resulting high EGT. Many owners suggest fitting an EGT gauge; this way you can monitor the heat and prevent the head from any damage. Always attempt to reduce an unsafe increase in EGT; practice proper maintenance on the pump and cooling system, injectors and air filter, and instil good driving styles in yourself. Doing these may all contribute to preventing any engine head problems. It is pleasing to know that the Colt’s block is at least bulletproof, and few people ever heard of a failing block. The problem seems to be only with the head that is susceptible to damage.

If you suspect an engine head default, then have a professional do a Tee-Kay head check with a combustion leak detector. The Tee-Kay is designed to check combustion gases in the cooling system and it is usually performed in the case of suspecting a leaking cylinder head gasket or a cracked block or cylinder head. It is also used when the engine overheats, when there is a loss of coolant, a rusty radiator condition, or even in the event of hard starting. Equally important, consider doing as many other owners have done and take your 2.8 tdi to your nearest SAC Service Centre for a thorough dyno and diagnostic check. It is at the end of the day far better to be safe, than to be sorry.

2.8 tdi Overheating

Another issue raised in a 4x4community (2011) forum that was also raised at 2carpros.com and at justanswer.com, is the problem of overheating. Apparently overheating is not unheard of in the Mitsubishi 2.8 tdi engine. There are many aspects to consider if you experience an issue such as this, but the first thing to remember is the following: the engine is cooled by way of airflow and coolant. The thermostat allows the engine to get to an operating temperature and then it maintains that temperature. The main cause for an engine to run hot and/or overheat can be due to a faulty thermostat that either open or fail to open. The problem some owners experience is that even after replacing the thermostat, the problem at hand remains. If it remains even after replacing a thermostat, then it does not necessarily imply that the fault lies elsewhere. It may be that the brand-new thermostat can be faulty, as part of a bad batch. Thermostats are relatively inexpensive, so try one from a different dealership or another parts supplier. Do not hesitate to contact your nearest SAC Commercial Parts outlet for quality aftermarket spares and accessories.

One 2.8 tdi owner resolved the overheating issue by removing the thermostat, but this is not only a short-term solution, it is also not an advisable thing to do. The thermostat is there for a reason. Whenever you acquire a new thermostat, always ensure that the thermostat is not a single action thermostat if a duel action thermostat is required. Also make sure when replacing the thermostat, that the little bleeder nipple is facing up when fitted. The position of the bleeder is very important. When you change the thermostat as well as the radiator cap, and the thermostat is an 88 degrees Celsius thermostat, make sure that you use a 0.9 kPa radiator cap. With a 78 degrees Celsius thermometer you should stick to a 1.2 kPa radiator cap. It may also happen that the dashboard reading will show a higher reading for normal temperature after installing a new thermometer, especially in the case of an aftermarket part. In other words, the gauge may show a higher temperature, but that does not necessarily means that the engine runs hotter. If you doubt your gauge, then get a digital reading of the water temperature with an infrared thermometer.

You may also consider the following probable causes for overheating and/or an engine running hot. Make sure that there are no blockages of air in the cooling system. Bleed the system and see if that resolves the issue. On the point of blockages, some of the tiny little pipes running inside the radiator may also become blocked. Flushing the radiator will not clean out the tubes; radiator specialist will have to remove the top and bottom tanks to inspect and clean it. Apart from blockages, also inspect the coolant and water system for any leakages. You may consider having a pressure test done on the system to see if there are any leakages present. While you are at it, check the water temperature switch. It usually sits on top of the head and have two wires connected to it. Inspect the water pump too, it is common for the pump impeller to wear down and not sufficiently circulate the coolant through the system. Another possible cause is the viscous fan. The viscous fan is hard to test, and if in doubt, it is better to replace it.

Let us conclude by reiterating the importance of the cooling system. Maintenance of the parts of your vehicle’s cooling system, such as the radiator, hoses and seals, is paramount. If you fail to maintain it properly, it can lead to overheating and this may cause serious engine damage.

2.8 tdi Cold Start

Does your 2.8 tdi struggle to start, then it cuts out while spluttering and smoking profusely? Is there clean diesel coming out from the top of the diesel pump? This issue was raised on behalf of a concerned Colt 2.8 tdi owner in a pajeroclub forum. The reason for this behaviour may be ascribed to a faulty input shaft seal of the diesel pump. If it does not seal properly and allow air to enter, it can let diesel into the sump. You do not want a faulty pump; it can cost you your life if you have a runaway engine from diesel dilution in the engine oil. Have the pump or seal replaced.

2.8 tdi Oil Leakage

Various oil leakages was experienced by an owner, such as oil leaking at a newly installed oil pressure switch, oil sweat around the top of the tappet cover, and a slight oil leakage at the clutch pedal. The advice given was to change the speedo drive (due to the oil leakage on the clutch pedal), tightening the oil pressure switch, and inspecting the half-round seals in the front and back of the tappet cover. Apparently, the rear seals tend to leak, and don’t fret, it is normal for some oil sweat to be present around the tappet cover and turbo pipe inlet to the manifold.

This brings us to the end of the discussion of the Mitsubishi Colt 2.8 tdi. Any issues highlighted here should in no way instil fear in you and/or drive you to a point to get rid of your bakkie. Many bakkie owners speak highly of the 2.8 tdi. However, if you experience issues and require any assistance, be it repairs, servicing, and/or spare parts, simply contact your nearest SAC Service Centre and make a booking, or head down to your closest SAC Commercial Parts outlet. At our SAC Service Centres, we have skilled technicians and mechanics, as well as high-tech equipment to assist you all the way; at our SAC Commercial Parts outlets, we offer quality aftermarket spares and accessories. For fast, friendly, efficient and professional service, choose us; choose Steves Auto Clinic.

Sources consulted during the writing of this article:

Within the above article, potential problems, causes and fixes have been identified as founded on the experience of vehicle owners and repairers, online sources such as discussion blogs, technical service bulletins and SAC experience. This information is provided solely for reference purposes. SAC strictly instruct readers that only properly qualified individuals should carry out repairs and/or modifications on your vehicles. It should also be made clear that the number of times an item is identified within this discussion should by no way be seen as an indicator of a model’s reliability or the frequency with which they may occur. Two of the exact same vehicles, owned by tow entirely different owners, driven in entirely different ways and on different terrains, and looked after in their own unique ways, will each behave differently. As mentioned, this information is provided solely for reference purposes but we hope – in the process of doing so – to empower you with relevant information which may enable you to make informative decisions whenever you experience any of the mentioned setbacks.