Engine bay: why can’t my car go beyond 170kmph?
Hi Paul,
I have a Nissan Elgrand model 1997. I have tried to drive it up to 180 kmph but when it reaches 170, it drops back. What could be the problem?
Israel
Hello Israel, your Nissan Elgrand 1997 comes factory fitted with a speed limiter which is preset to lock your top speed at 177 kilometers per hour (approximately 110 MPH). The speed limiter facility is programmed with your engine control module to prevent you from exceeding what is considered a safe speed of the vehicle according to Japanese Domestic market regulations. Speed limiter systems are often used by fleet owners to regulate the speed of their drivers. This is intended to enhance road safety as well as reduce traffic fines picked up by over speeding drivers. Fleet owners are also concerned about the increasing fuel and repair costs arising from over speeding and accidents. Using the in built speed limiter made the Elegrand an attractive choice for buyers back in 1997.
Hi Paul,
I have a Toyota NOAH 2004 which I have been told runs on D4 engine and it is 4 wheel drive. I have to change it’s oil regularly because it turns watery and have discovered that fuel is mixing with oil. What could be the problem. Another mechanic told me that he suspects the D4 ‘s seal is worn out and needs replacement. Is this possible?
Wanangwa
Hello Wanangwa, the D4 (direct four) high pressure pump seals have failed and your mechanic is right you will need to replace it. The D4 Toyota engine in your Noah relies on a high pressure fuel pump to pressurized the fuel rail and electronically regulate precise amounts of fuel at a time. This results in a more efficient engine running. The D4 high pressure pump is partially inserted in the engine because it is driven by the engine camshaft as it pumps fuel to the common rail for delivery. Seldom the pump seals which separate fuel from engine may fail as a result of engine oil quality or service routine. When the seals fail there will be a cross flow of fuel to the engine oil system. You will need special tools, know how and expensive repair kits to rebuild that pump. Outright replacement with a similar new or quality used unit seems to be your only option.
Paul Kaganzi (0772316145)
