when to change your glow plugs

There is no officialy recommended service interval for BMW glow plug replacement. They differ from petrol engine spark plugs in that they either work or they don’t and a failure can be very sudden, unlike spark plugs which deteriorate over time until they eventually fail. For this reason, glow plugs are replaced only when they fail, not as a maintenance item.

Glow plugs are crucial components for the smooth running and cold start-up of your BMW diesel engine and when they fail, you will experience long engine cranks and difficult start-ups along with misfires when engine is running cold.

We advise that you replace the glow plugs only if you are experiencing issues with cold start up or cold engine running.

snapped glow plug removal

If your glow plugs have not been replaced for many many years, their threads could be seized due to corrosion and carbonisation. We can service your existing glow plugs to keep this problem in check by;

• carefully removing the BMW glow plugs

• thoroughly cleaning the threads on the cylinder head and glow plugs

• lightly lubricating glow plug threads with high temperature ceramic grease

• reassembling and torqueing each glow plug to exact specification

   

If your glow plugs are badly seized and happen to snap during removal, we can have them removed by a special method using precision engineering tools.

Glow plugs are highly prone to snapping when seized which is largely due to their weak external construction compared to spark plugs found on petrol engines.