No power to glow plugs...all 4!

[Cleo]

05 octy 1.9tdi

No wonder the f?£&@;n thing's hard to start...after some googling I found that it's maybe either fuse 2 at the battery with a red wire/cable coming from it or and/or a relay (under the dash, upper top row 4th from the left with 103 on it)....it's these are ok, what else do I look for/check

I also read about someone taking the temp sensor out, you still get the glow plug light in the dash and it starts as it should, but obviously you can't go about with a sensor out, well I don't think you can, not for long.....but where is it? If I wanted to try

[Cleo]

No one's ever had this then and cured it, ******

Edited 28 November, 2014 by Cleo

[Rustynuts]

Glowplugs don't work unless the outside temperature is down to near freezing point. Glowplug light is not an indicator of gowplug function either. Poor starting this time of year is unlikely to be faulty glowplug issue, more likely weak battery or failing starter motor, or camshaft timing out of adjustment.

[erindad]

On the VW Passats the coolant temp sensor decides if the glow plugs (if everything else is working properly) come on or not . If it is faulty/corroded plug then the glow plugs are not energised. The one I cured for bad starting after finding the glow plugs were not working had a corroded plug, fitted new sensor and cleaned connections and away it went , first time and every time. 

 

It is I think a similar setup on the Octys.

[Cleo]

Glowplugs don't work unless the outside temperature is down to near freezing point. Glowplug light is not an indicator of gowplug function either. Poor starting this time of year is unlikely to be faulty glowplug issue, more likely weak battery or failing starter motor, or camshaft timing out of adjustment.

I was told diffirent ie they heat up when cold, what's the point in the light coming if it's not doing anything, stupid that. Yes bad starting was the glows, or quite sure it is, but it's because they're not heating, the starters fine as is the battery, he checked the timing and it's fine too. The only code that came up was the cam sensor, so if it's not the glows it's maybe that.

I was out last night, and noticed that (this doesn't all the time but sometimes) when starting, if use about 1/4 accelerator, it can start easier, weird but that's what I found

I've got a auto spark hopefully coming shortly to see why the glows aren't getting power, then hopefully next week it's the engine mounts, then hopefully the right springs and wheels and get these 245/45 tyres off, christ, tyres that size on a bloody octy (rolls ayes)

Edited 29 November, 2014 by Cleo

[Rustynuts]

Glowplugs DO heat up when it's cold, but in days of old when diesels were agricultural they were required all the time. On modern diesels with direct injection and ecu control for injection timing and duration, they don't work all the time. Just because they're not working doesn't mean they're supposed to work. They only work when the ecu decides they're needed.

[Cleo]

I know, he explained how they work on modern diesels, they should still glow with ignition on but mine don't hence no power going to them.....if the spark turns up I wonder what he'll find, known my luck, something that costs a bloody fortune

[Rustynuts]

They do not glow when you turn the ignition on unless they need to. If the temperature read by the ecu dictates there's no need for glowplug function, then they do not work, full stop.

 

As I said, just because they're not working it doesn't mean they should be working, it just means that there's no need for them to work. I could go out to my car right now and check them, but I know they won't be working because the temperature is above the level where they're needed to function.

[Cleo]

Right, the auto spark was here...glow plug relay's fkd, tested everything and traced it to that, he took it out and said get one of these, he was going to fit a bypass switch if it'd been the body control module, but not this. I asked about starting and yes you're right, he said as its not been started today yet they would glow, after that probably not as it's the cam sensor takes over (I need that too as I got the code up for it)

A relay's 75 (dealer only) cam sensor 20odd gsf

After that....it's the springs and wheels to sort out THEN it'll be hopefully better and comfier to drive

[satire111]

 the glow plugs in a pd tdi engine

 

As the vehicle ignition is turned on the engine ECU determines the engine temperature via the coolant temperature sensor and uses the mapped in calculations within the engine ECU to determine if the glow plugs need to be switched on at cranking, this is usually around 5- 9 degrees centigrade in the uk  the timing of the on period is also pre determined by the engine ECU and the use of the glow plug relay unit 

then 

 

 

Once the engine has started, the 4  glow plugs continue to operate (yes, continue to operate) in order to reduce engine noise,(diesel knock) improve idle quality, and reduce exhaust unburnt diesel emissions. 

This afterglow function is thus carried out after every engine start until a specified time has expired or until the engine exceeds 2,500 RPM's - whichever comes first.

[cheshire_cat]

 the glow plugs in a pd tdi engine

 

 

 

 

Once the engine has started, the 4  glow plugs continue to operate (yes, continue to operate)

usually at reduced power