When you disengage the clutch (depress the pedal), the load on the engine reduces, assuming you are travelling on a level road or uphill. If the accelerator pedal position is not changed, the revs will increase.
If you are going downhill, the revs will drop as the wheels stop trying to drive the engine.
The symptoms on your vehicle looks like something in the drivetrain (after the gearbox), probably the brakes is causing a lot of resistance. First of all, do check if any of your brakes (wheel hubs) are overheating after a short drive.
Also check for presence of any oil in the coolant system, which could point to a blown head gasket. |