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Ask the mechanic: What is wrong with my gear selector?
There are a number of reasons why your Gear Selector might fail or take long to change gears and these include poor engine performance. NET PHOTO
Hi Paul,
Thumbs up for the great advice you always give car owners and drivers. I acquired a VW Golf estate model 2001 about three years ago. After the first year, it started having issues with its gearbox. Even when I would replace the gearbox, it would affect the car and it would not change gears. I decided to replace the engine and gearbox. This served me for a little while and the problem has resurfaced. Recently, I was driving to Kabale when the car engine check light came on and the car could not change gears. I thought this was due to the old transmission fluid. I had the gearbox serviced but now I find it hard to accelerate beyond 60kmph. Please advise.
Maxwell.
Dear Maxwell, sorry about the frequent breakdowns with your VW Golf MK IV station wagon. The check engine light is displayed permanently on your dashboard when the engine management system detects a power train fault which is affecting the engine emission. Engine emission is determined by how efficient fuel is burned in your engine. Your VW engine may be suffering from incomplete combustion or misfire which might be caused by restriction of fuel supply or spark. This will invariably affect your engine power and acceleration. Poor engine performance will also affect the quality of your automatic transmission gear shifts. I believe you need to find out the cause of the emission fault first before replacing the gearbox the third time. An emission fault is detected by the engine computer (ECU) using values communicated by sensors like the air flow sensor, oxygen sensor and camshaft position sensor. The ECU records a specific diagnostic trouble code (DTC) which can be read by a computerised diagnostic tool at the nearest VW garage. Its worth noting that faulty engine management sensors like the oxygen sensor or air flow sensor can also cause the computer responds to wrong values (information) causing emission fault and the check engine light.
Hi Paul,
I have an issue with my VW Golf iv car. When you ignite the engine, it starts but when the gears start moving from one to two, the third gear goes free and it does not change to another. I have been told that it’s a wiring problem. Advise me before I mess up my car. Joshua H
Hello Joshua, it seems the automatic transmission of your Golf iv may have a faulty electro-hydraulic valve body. This unit is as the logistical hub which delivers hydraulic oil to the selected gear according to the engine demand. The valve body houses electronic solenoids which work as gate valves to release oil to the right gear bundle as instructed by the computer. The solenoid valves can be damaged by bad transmission oil, electric short circuits or a faulty gearbox computer. In your case, it seems the solenoid for gear no. 3 is faulty.
Perhaps that is why your mechanics have suggested the possible presence of an electric fault. To avoid misdiagnosing the transmission computer, it is prudent to carry out a computer diagnosis and a car electrician should test circuits between the transmission computer and gearbox valve body.
Hi Paul,
I closely follow your column every Thursday to get to know more about cars. My problem is that when reversing, the gear selector goes to neutral; the same applies to when driving uphill, it shifts to neutral thus making me panic. What can I do to solve this problem?
Ismail.
Hello Ismail, automatic transmissions rely on clean and suitable transmission fluid (ATF) to engage the gears using viscous (fluid) pressure. When you run the automatic transmission without servicing or renewing the ATF, you risk damaging the internal components such as gear clutch bands and solenoids in the hydraulic valve body.
Ask an experienced mechanic to drain a sample of the used transmission fluid from the pan and inspect it for presence of metal debris or burnt gear clutch material. Should there be no sign of mechanical damage, the mechanic should check the transmission electrical system (circuits, harness, control module and solenoid valves).
Hi Paul, my inquiry is about the dashboard lights particularly the engine management light (ECU / engine warning light). Sometime last year, it lit up then I caused more damage when I used online aids that said I should change spark plugs. That was in September. The light pops back on usually after driving for a few kilometres. In your expert opinion, what could be the problem here?
Henry
Hello Henry, the check engine light is a flag by the engine management system alerting you about a fault affecting the engine emission system. A faulty ignition system (spark plugs, coils or high tension leads) can cause the check engine light. A failure of the fuel delivery system (pump and filter), air flow sensor and oxygen sensor can affect the engine management system and cause the check engine light. A computer diagnosis will point at the cause immediately.
Hi Paul, How do I check the year of manufacture for vehicle tyres and which years should I reject? Thank you. Ambrose.
Ambrose, you have asked a very pertinent question about the date of manufacture of tyres and when tyres should be considered expired. Tyres will expire whether driven on the road or kept in a secure dry room. Tyres are made of mostly rubber which degrades with age, sunlight, heat, cold weather or general wear due to use. The rubber compounds in tyres will age when exposed to oxidation which makes them brittle and easy to damage. This makes these tyres susceptible to cracking of tyre walls, tearing or peeling of treads which can be very hazardous to motorists.
It is, therefore, useful to know the expiry date of your tyres. Most leading car manufacturers, national road safety agencies and tyre safety groups concur that tyres should be considered expired six years from the date of manufacture.
Being able to tell the date of manufacture of your tyres is the first step towards knowing whether they are expired or not. All tyres sold by recognised tyre manufacturers comply with the requirement of the Department of Transportation certification (DOT) to display the date of manufacture.
The week and year of manufacture codes are clearly etched on the side of each tyre wall in a cylindrical window next to the DOT code. You can use this guide to confirm the age or expiry date of the tyres on your car or those that you want to buy.
Ask the mechanic
By Paul Kaganzi
0772316145
send sms: mycar (space) your comments and questions to 6933, or email them to [email protected]
