On our Renault Scenic a large plastic tea-tray shaped flap has come down underneath the engine block. What is this for and is it easy to repair?

Answer 1

The plastic tray is used by many car manufacturers to protect the lower half of the engine and engine compartment from road dirt and damaging stone impact. It is also used to reduce wind noise and improve air-flow under the vehicle. The easiest way to keep it in place is to use large cable -ties and thread them through the original bolt hole then through the hole in the tray. Pull the cable tie tightly and it will keep the undertray secure. Originally these trays are attached by bolts that screw in to threaded clips which attach to parts of the underbody. These threaded portions and the bolts often rust out and snap. Many auto-supply stores sell the threaded clips and a selection of bolts to fit. Caution. On the Scenic you may have to raise the vehicle to get to the rear most tray fastenings. Use metal car ramps to get the front up. Depending on what model year your Scenic is they can be awkward to raise on a trolley jack because they don't have a traditional sub-frame or structure suitable for lifting front wheels off the ground. Don't be tempted to use tyre changing jack either as this is only meant to raise wheel off ground for wheel change. You may find the front tray clips have broken and they can just about be accessed with car on the ground.