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chicaneuk

530d Glowplugs Replaced.. kinda..

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Hey folks..

 

Tackled glow plug replacement on my 530d and unfortunately it didn’t go entirely swimmingly as one of them sheared off when I attempted to remove it. I also used aftermarket intake manifold gaskets (BMW wanted nearly £100 for a set which is just too damn much) to replace the old ones and seem to have been left with a massive air leak somewhere as as soon as you get on the power, there is a very loud sound of turbo boost / air noise coming from behind the dash, and the car feels correspondingly flat, so the manifold is going to need to come off again for a check over.. 

 

Despite only being able to replace five glow plugs, the car does seem to feel better for it and it seems to have cured somewhat the problem I always had of the car REEKING of dirty diesel fumes on idle.. seems much cleaner out of the exhaust now. It seems quieter and smoother at idle too. 

 

My two questions are.. any idea on the typical amount of labour for a garage to extract the stuck glow plug? I don’t fancy trying it myself! Secondly, the glow plug sheared off pretty high up.. I am assuming that they are a solid object internally and block up the hole to the combustion chamber.. I wondered if the sheared plug was the cause of the air noise and not the cheap gaskets but I am fairly sure they are solid internally so that can’t be it..? 

 

Thanks. 

Edited by chicaneuk

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Sorry to hear your woes but out of curiosity why change the glow plugs? I thought they only helped cold start. Do they have another function?

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I have read on numerous occasions they help with general running on these engines including fuelling at idle. Also always got glow plug fault codes when I scanned the car so wanted to take care of that and they are a cheap part and, in theory, reasonably easy to do if they decide to come out! :) 

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The general advice I read prior to starting was: 

 

* Warm the car up thoroughly first (though you will need thick gloves to work on things as the bolts get hot!) 

* Give the plugs a good soak with a penetrating spray prior to starting to take them out - ideally you'd have the manifold off, spray them, reassemble, and remove the manifold the next day with the car hot again.

* Use a torque wrench that can loose as well as tighten, set to around 20 lb/ft and give up if the glow plug doesn't want to back out without exceeding the torque value.

 

I only followed one of those pieces of advice (got the car up to temperature first) as I'm impatient and foolish.. and now I have a glow plug stuck in the cylinder head! But otherwise it's a totally straightforward process. 

Edited by chicaneuk

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You are probably looking at a couple of hundred to remove the stuck one.

I did the same as you apart from following recommendations, bought a Norbar calibrated push through wrench, started soaking the day before as you could get the straw through the inlet onto the plugs on mine (E6x), I then took everything off the inlet, put it back together loose and ran it up to temp, then removed as fast as possible and cracked free all 6 plugs, the 6th had cooled a bit more and I put the wrench up to 25nm and it gave one last chance and it came free.

Due to the cost and implications of having a broken plug I did it as slowly as possible, backed the plug off a turn, hit it with plusgas and turned it back and forth until it was free then did the same again until each was out to give them the best chance, I had the time to do it.

 

Garages have torque limited impact guns specially for these jobs, if you have £150 spare and a compressor I expect this is the better way to go about it https://www.ebay.co.uk/itm/GLOWPLUG-HEATER-PLUG-REMOVAL-TOOL-SET-AIR-IMPACT-GUN-SOCKETS-8-12mm-/162730940377

Edited by GoNz0

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Couple hundred pounds I could live with.. I'm not sure what I was thinking really rushing the job, knowing full well that these things do have a habit of breaking. I suppose I was lucky that it was only one. I'll have the manifold off again and see if I can see what's causing this massive air leak and then think about whether to ring around and get prices for the job.

 

Cheers.

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Top tip - thanks! From the amount of noise it was making, it should be fairly evident once I remove stuff.. I can't help but wonder if one of the little rubber gaskets simply dropped out of the manifold as I was putting it back in place, but that said I would expect it then to be more of a single cylinder "chug" whereas the noise is like a full on WOOSH like I've got a split in some of the turbo pipework or something. Really hope I didn't crack the intake manifold somehow - that wouldn't be amusing.

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13 hours ago, chicaneuk said:

I have read on numerous occasions they help with general running on these engines including fuelling at idle. Also always got glow plug fault codes when I scanned the car so wanted to take care of that and they are a cheap part and, in theory, reasonably easy to do if they decide to come out! :) 

 

I'm intrigued as to how and why the glow plugs would effect fuelling at idle...... Not in any way shape or form saying that I don't believe you as I have literally zero experience with the M57 engine I'm just curious that's all....

 

I am also in the old school train of though, along with Duncan, that the sole purpose (I/we presumed) was to heat up the top of the combustion chamber to enable an easier cold start scenario.....

 

13 hours ago, duncan-uk said:

Sorry to hear your woes but out of curiosity why change the glow plugs? I thought they only helped cold start. Do they have another function?

 

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I can't remember where I read it but I'm sure I have read it and in several places too. Maybe I just imagined it.. entirely possible :) If I manage to find a link I'll share it.

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7 minutes ago, Clavurion said:

After-heating takes place after engine start at temperatures below 20 °C in order to improve idle and exhaust characteristics. CLICK

 

Again, unless I'm missing something its still all cold temperature related....  Also that explanation is a little vague too; what is below 20 °C??!! And how long is the delay?! The coolant or the ambient air?!!! I'm assuming air, but if say its 18°C outside, the glow plugs might come on for a few seconds after starting to smooth out idle etc but can't see them being permanently left on just because its a bit mild out lol. Once the engine is up to temp surely there is no need for glow plugs?!

So I'm still of the opinion that the glow plus are only used for the first few seconds of start up......

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8 minutes ago, boiliebasher said:

 

Again, unless I'm missing something its still all cold temperature related....  Also that explanation is a little vague too; what is below 20 °C??!! And how long is the delay?! The coolant or the ambient air?!!! I'm assuming air, but if say its 18°C outside, the glow plugs might come on for a few seconds after starting to smooth out idle etc but can't see them being permanently left on just because its a bit mild out lol. Once the engine is up to temp surely there is no need for glow plugs?!

So I'm still of the opinion that the glow plus are only used for the first few seconds of start up......

 

Coolant temperature. So yes they are only used when engine is cold. For example glow plugs are not used if the engine has warmed up (or pre-heated) even if the outside temperature is -30 °C.

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14 minutes ago, Clavurion said:

 

Coolant temperature. So yes they are only used when engine is cold. For example glow plugs are not used if the engine has warmed up (or pre-heated) even if the outside temperature is -30 °C.

 

Right o, that makes sense to me. So its pretty much what Duncan and I had assumed,  the plugs are only used for a cold start scenario and nothing more.....

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Fair enough! Maybe I misunderstood what I'd read about how they're used. I'm still happy enough with doing them as a DIY job though - they're cheap to buy, and having the manifold off is easy enough.. just the whole snapping of the glow plugs that is a bit of a shame and makes it a less attractive job :)

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Agreed lol. If every time I did maintenance work I knew there was a good chance of breaking something (your not the first person to break a glow plug in a M57 and I doubt the last either) I wouldn't touch anything at all unless the engine refused to start all together. It's the law of it ain't broke don't fix it lol  :)

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