Any Problems Removing Glow Plugs

[GAJ52]

Hi

I intend to replace the Glow Plugs on one of my BMW Mercruiser engines. As these appear original by the paint still on them and are approx 27 years old, I'm a bit paranoid about trying to remove them and shearing the plug. Apart from soaking the plugs in Plus Gas, has anyone any further advice in making this as trouble free as possible. I've never broken a spark plug yet but this is the first time I've changed a Glow Plug and they look more flimsy.

Glen

 

[rob2]

I changed the plugs on my old Sole diesel - no trouble, just like changing a spark plug. Not quite as old as yours, but being original they hadn't worked for some time. With the new ones fitted, the engine starts willingly from cold. I didn't even think of them as fragile, so handled them without any tremulations - probably saved me from any problems. It is important that you find a well fitting spanner, though. I used a long socket, so there was no strain on the ceramic part of the plug.

Rob.

 

[Jcorstorphine]

I don't wish to worry you but I sheared a glowplug on my old BMC 1.5 Diesel and had to take the head off to clear out the debris left behind.

I do not think the Plus Gas will make it any easier to remove as the plugs initially as they usually seal on a shoulder so the liquid does not get into the thread or the glow section. However you should still give it a soak, just in case it wicks in.

I would suggest that if you get it to move a little, squirt some more Plus Gas and leave for 10 mins to allow it to penetrate.

 

[pampas]

Use a ring spanner or long-reach socket, firm pressure not a jerking pull, should come out ok. Tip. before fitting ne ones use a drill and clean out the holes, engine manual should tell you the exact size, around 11/64" twist in your finger DON`T use in a drill

 

[GAJ52]

Well my fears where unfounded, just got back from the Marina. The glow plugs came out very easy, don't know why I was panicking. As suggested above I did initially crack them then give another squirt of Plus Gas and they unscrewed almost by hand.

I can see why the engine was difficult to start from cold, only one of the six was working.

Thanks for your comments

Glen

 

[Baddox]

You were right to be cautious as glow plugs are thin walled and not very strong. New ones are supplied with a max torque setting which is always pretty low. A tip for anyone else doing the job is to get the engine up to temperature before trying to remove the plug. Some manufacturers recomend greasing the plug shaft with a little ceramic grease before re-installing.