XSeries-forum

I have just replaced the glow plug control unit and I have gone from all glow plugs not working to just 5 and 6 not working ( so guessing they need replacing next) but I still have no glow plug light showing on dash with ignition on not even for a split second! Is this normal or is it because no. 5&6 are still not working or maybe another reason?

Normal unless it's about 5C or so.

Richard

That's ok then. Does this mean that the plugs don't operate until it's belows 5c or just that the car doesn't really require heat?

It's hard to find definitive info but I did read a post straight from a BMW technical document that said: glow plugs will have an active pre-combustion role when engine coolant is below 25 degrees. When engine coolant is below 30 degrees, it will also have a post-combustion role to help burn off emissions. Am guessing this is related to EGR.

My mechanic told me that they had a role to play at all times in ensuring clean combustion but I haven't read any evidence to support this.

My own conclusion is that if the car is starting up fine and not rough idling when cold - don't worry about it.


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Mine shows up on diagnostics as all 6 not working, starts perfect every morning and it was bellow 5 last Sunday , puffs some smoke out when it's cold mornings  but in warmer weather it was fine , I'm a bit reluctant to changing the glow plugs and relay atm.

Timx5 mine was the same, ran and started great ill all 6 not working even in he winter but I just wanted to eliminate the puff of smoke in the mornings.

Thanks for the help/info on this guys

[quote="b20wht"]
Timx5 mine was the same, ran and started great ill all 6 not working even in he winter but I just wanted to eliminate the puff of smoke in the mornings.

Thanks for the help/info on this guys
[/quote]

Did it stop the smoke.

I would say its slightly improved but i have today checked and I now have 1,5&6 glow plugs not working so it should improve when I replace these (not sure when that will be though)

[quote="b20wht"]
I would say its slightly improved but i have today checked and I now have 1,5&6 glow plugs not working so it should improve when I replace these (not sure when that will be though)
[/quote]

I think when I get round to doing mine I'll  replace all 6 glow plugs and the control  unit at the same time.

Even with all six working on mine I still got a small puff of smoke in my E53 on cold mornings, and our E46 with the same engine is exactly the same.

Richard

im not convinced that the puff of smoke on cold start up is down to the glow plugs. mine, with scanner showing 3 plugs down, always gives the puff summer or winter. my old 330d, now over 200k miles, still never puffs smoke and scanner says 5 plugs gone on that. it must be something else in the e53 engine design that causes it.

Could just be over fuelling for the start?  In which case it's gotta be pretty much guaranteed you'll get a puff.

Richard

My E53 has had 3 failed glow plugs for a year now, with no starting problems. It appears that engine ok with no glow plugs down to very low temps. Big job to change as need intake manifold off.

Small puff probably due to a leaky injector.

Mine used to do it until I got them returned.

As above, if it starts and you don't lose rear view then don't worry about it..