The Rover V8 Engine Checkup

Is your Rover starting poorly, stalling at lights, idling erratically, using too much fuel, too dirty to pass Emission Inspection? An $80 diagnostic service in our shop can show you all you need to know to keep your Rover healthy.

The computer that manages your engine's starting, running, fuel consumption, and idling is pretty clever and can even compensate for some wear or inaccuracy in sensors. However, we are finding more and more that, as these engines get beyond 80,000 miles, they benefit from a little preventive maintenance. Sometimes that means finding and fixing vacuum leaks, sometimes replacing the water temperature sender, sometimes cleaning or replacing the Oxygen (O2) Sensors.

Knowing what to do when there is a problem but nothing has failed badly enough to trip the 'Check Engine' light has, in the past, been time consuming or required expensive dealer systems but, at Flying Circus, we have routinely checked and road tested Range Rovers, Discoveries and Defenders using our own laptop system:

This setup is a Fluke 98 oscilloscope and our own tester/breakout box which we connect between your car's computer and the wiring harness. This unique tool allows us to drive the car while watching for weaknesses in the engine's management system. In just one road test we can verify that:

• The 2 critical Oxygen sensors are warming up quickly enough and operating fully
• The Throttle potentiometer has no acceleration 'flat spots'
• The Water Temperature Sender is accurately reporting engine temperature
• The Fuel Temperature Sender is accurately reporting fuel temperature
• The Idle Control circuit is working properly and parking ready for the next day's cold start
• The ignition primary side is triggering the coil to make a good spark
• The Fuel Injectors on both sides (they are independent) open for the correct duration
• The Alternator is producing adequate volts
• The Gear Selector is correctly reporting when it is in 'Park' and 'Neutral'
• The computer knows when the A/C compressor is being powered
• The Fuel Pump Relay is 'pulsed' before cranking
• The road speed sensor is working
• and several other important checks that affect proper operation

When a test sequence shows that all the values are within the specified limits it makes it possible to send the car back into service with confidence. When we find a problem that affects performance but has not yet tripped the 'Check Engine' it means we can clean up the vehicle's behavior and avoid the dash warning.

Your vehicle's system can be dignosed and a printout of critical sensors made for $80. It takes about 1 hour and is a smart investment whether you already sense a problem or just use it like an annual checkup.

This printout of the behavior of the Oxygen Sensors is one of several typically recorded during a diagnostic run. In this instance it showed that there was a proble and pointed to a possible sensor failure of Bank A or another fault somewhere in the same bank. Either way the sensor had to be verified as good. After all, it not only tells the engine's computer what to do, we need to read it to understand what is going on in the combustion process. When the O2 sensor was cleaned and bench tested, response was improved and the proper pattern returned to both banks. Without this intervention, the engine management system would probably have deteriorated until a failure occurred.

Call Flying Circus for an appointment for a full engine management check. It's a smart move and now a complete check can be performed in about an hour.