QuestionI recently bought a 2002 Land Rover Freelander. I bought the car at 36,000 miles, and it ran great for the six months that I've owned it. Just recently my engine light comes on. I take the car to the Land Rover dealership for repair. They diagnosed that I needed four new vacuum hoses, and new oxygen sensors for the front and rear. They're charging a ridiculous amount of money for this repair. I found it strange that a 2002 Land Rover needed new oxygen sensors at 41,000 miles, which is the current mileage on my vehicle. How do Oxygen sensors fail? And why would I need four new vacuum hose? Why would the sensors fail at only 41,000 miles? Should I take it to another mechanic for a second opinion?
AnswerHi Kimberly,
good questions.
If you talk to o2 sensor manufacturers, they'll tell you that the sensors should be treated much like the spark plugs. They even suggest more frequent replacement then currently performed.
Most vehicle o2 sensors are subject to all sorts of abuse unknown to the owner. Failure is usually a result of deposits on the probe tip which prevent proper measurements. Oil additives, water, even silicone can ruin the sensor. Then there is the ingress of oil and road contaminents within the wiring and electrical harness (a problem that many LR owners face).
"...causes of early sensor failure are deposits on the probe tip that prevent the tip from accurately measuring the amount of oxygen in the exhaust gas. Silicone, condensed water, and some oil additives can contaminate the sensor.
In addition, sensors can be subjected to extreme temperatures, oil fouling, carbon deposits, and the corrosive effects of a myriad of harmful chemicals during a "normal" life. Eventually, even the best oxygen sensor, operating in the cleanest engine, will wear out."
In your case, you are the 2nd owner and there exists a question of how the Freelander was maintained before you purchased it.
As for vacuum hose replacement, this I don't understand. Unless you live in a dry climate, your engine is running at extremely high temperatures, I don't know why ALL those hoses would be replaced. Is the dealer just swapping out some parts to solve a problem they don't understand?
A second opinion from an independent LR mechanic would do well in this case. Hopefully, the repair bill will be far less than the dealer and the diagnosis more accurate too!
Best of luck,
JohnMc
