Introduction: The OEM spark plug fitted to the MGF is the Champion RC8PYP or Unipart GSP 9652 for the VVC and mpi, which are defined as long life (platinum tipped) and are due to be replaced at 60,000 mile intervals. The choice of these plugs by MG Rover appears to have been due to the perceived complexity in getting to them, and probable cost to the end user. In fact these are an easy item to DIY replace and can provide a genuine benefit.

Adequate performance can be maintained for the full 60,000 miles, however, it is clear that most drivers notice the drop in performance long before then. Evidence suggests that long life plugs work fine until the low to middle 20k miles, and thereafter drop in performance but still allow adequate performance until the recommended change point. A standard copper core plug would be well past its best at 6,000 miles, so this is a significant improvement. One thing is certain, changing your plugs early will help your MGF.

The choice of replacement plugs available is bewildering and in some cases down to personal preference. There is no evidence to suggest that long life plugs are essential to the well being of the MGF. Using copper core plugs and replacing regularly can be cost effective, as the long life plugs are very expensive. Recommendations on the MGF BBS include NGK and Bosch if you don't like the Champions. Whatever you pick, do change those plugs.

Step 1: Gain full access to the engine bay (see FAQ "Open Engine Compartment").

Step 2: The spark plugs are located under a plastic cover running across the centre of the engine (Photo 1). Remove the cover by undoing the two cross-head screws and lift away.

Step 3: With the cover removed and viewing from the rear of the car, the cylinders are numbered 1 to 4 from right to left (Photo 2). If this is the first time of changing the plugs, make note of the way the HT leads run through their guides to their spark plug for replacement later.

Step 4: Repeat the following for each plug in turn...

1. Remove the HT connector from the plug. The plugs are deep set and there are finger grips on the HT lead. Use these, as pulling on the HT lead will almost certainly snap it without removing it from the plug. It is worth twisting the lead before pulling to break the seal between plug and lead. This should make removal much easier.

2. Using a 10mm box plug spanner or plug socket, remove the spark plug (turn anti-clockwise).

3. Where appropriate check and adjust the spark plug gap of the new plug to be fitted to that as specified in the owners handbook.

4. Fit new plug into box plug spanner and screw into plug hole. Tighten until properly secure, but do not over tighten to save damaging plug or head.

5. Replace HT lead onto plug. The HT leads are a snug fit on the plug, so ensure that the lead has snapped into place. This is often best done when the area is quiet and you will hear (and feel) a click as the lead snaps onto the spark plug.

Step 5: Replace the "Rover" HT lead cover. Note that the "Rover" inscription on the cover reads the correct way when viewed from the front of the car (Photo 3).

Step 6: Replace the engine cover as per FAQ "Open Engine Compartment"

Notes:

• A plug socket and extension can be used to remove the plugs, but it has been known for the extensions and the plug socket to become detached. If that happens then your plug socket is some 8" (20cm) down a very small hole. The few pounds for the box plug spanner is money well spent.

• If the plug is tight and reluctant to move, then apply some penetrating oil (eg WD-40) into the plug hole and leave to work. Try again and if still stiff, Spray some more oil, re-tighten and loosen off again, then wait some more. This may take some time but is better than a broken plug or stripped threads. Waiting can be some time (almost 1.5 hours for me) so be patient.

13th April 2002, David Mills