Ask the mechanic: Why does my car run out of oil?

Thursday December 13 2018



Pajero GDI

Pajero GDI 

By Paul Kaganzi

Hello Paul, my Pajero Bitama 2009 model runs out of oil even after changing the cover. A mechanic advised an overhaul of the engine and also buying a new oil pump. What may be the cause? Matthias

Hello Matthias, when the level of engine oil drops or reduces between service intervals, it may be due to leaking oil seals or if the engine burns oil due to damaged piston rings. There are signs and symptoms you could use to reinforce the decision to overhaul the engine. For example, if the oil level has to be topped up by more than one litre between a 5,000 kilometre drain interval, emission of blue exhaust smoke, a strong sign of engine oil burning and loss of engine power due to low compression.
Compression is what an engine does when the pistons during the upward stroke squeeze the fuel air mixture and confine it in a small space before it is combusted by a spark. How much air fuel mixture an engine can compress will determine how well the engine performs. Damaged pistons ring will leak compression as they leak oil into the combustion chamber. Your car engine compression can be confirmed with a compression test. Loss of compression will most likely be a result of leaking piston rings. A new oil pump may be required to ensure prompt delivery of engine oil to avoid damage.

My car stopped in the middle of Mabira Forest

Hello Paul, I recently travelled to Jinja in a pajero GDI but while in Mabira Forest, all lights went off when I indicated to overtake. What could be the problem? Also, when I reached Kampala and parked for some time, the car could not start. After jump starting it, the engine started. Whenever I engaged drive, the engine would go off to the extent that I left the car there overnight. What could be the problem? Siraj

Hello Siraj, that Pajero may have three different issues. The first one is an aged battery or faulty charging system. The long journey to Jinja and back should have charged that battery enough to make it start at the mall. First rule out battery or alternator failure. This may have something to do with the lights switching off when the alternator was loaded. Also, have the lights cluster switch checked for a damaged circuit.
Engine stalling when you engage drive is a sign of low power. Have the fuel system inspected particularly the fuel filter (may be due for replacement), fuel pump performance and the precision GDi fuel injectors which are sometimes affected by deposit build up inside the engine which acts like lime scale on a shower head. This affects prompt delivery of fuel pressure and reduces engine power or efficient performance. Advise the owner to fuel this GDi Pajero with Shell V-Power formulated with Dynaflex technology. Its more powerful cleaning additives will instantaneously clean old deposits and corrosion off fuel injectors and other fuel system components and keep them clean.

My gearbox does not shift well

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Hello Paul, I drive a Mitsubishi Chariot. My automatic gearbox has not been shifting well and my mechanic says the gear clutches need to be changed. What is your advice? Chris

Hello Chris, you need to consider overhauling the entire gearbox with new parts not only the gear clutches. The challenge will be finding genuine new repair parts for your gearbox. The more affordable alternative is to buy a quality used automatic gearbox imported by used parts dealers, from Japan. A failure of the clutches will be a result of a breakdown of components in the hydraulic oil delivery system. An automatic gearbox uses pressurised hydraulic oil to engage gears.
The complex system requires an intelligent oil delivery system (solenoid valve block /valve body) which works like water taps or gate valves but turn themselves on depending on the need, a set of gears (planetary gears), coarse frictional plates to trap the hydraulic fluid and help to engage gears (gear clutch bands), a pump and torque convertor to deliver pressurised oil (hydrostatic effect).
When the gear clutches fail, as your mechanic suggests, it is usually a result of a breakdown of the above system often due to a poor maintenance regime with the wrong oil. A quick fix by replacing the clutches will leave the cause of their failure unresolved. You would need a complete overhaul of the above parts.

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