General Question about Glow Plugs

[muddy panda]

I own a Panda 4x4 Diesel on a 63 plate, I've had it 2 years. It's a great little car with the full winter pack & I get great fuel consumption of about 55mpg.... however I'm a little concerned about it's Glow Plugs.
A "Glow Plug" message first appeared when we got our first cold snap last winter & kept appearing until Jan 2018. It then went away but started again in May. It comes on at start up but always goes out after about 20 seconds. The car seems fine, no other problems that I'm aware of.
Has anyone else experienced this problem, and if so, how did you resolve it?

 

[Herts Hillhopper]

The car I've just sold tended to do this too. There are two scenarios that make that warning show... one is one or more failed glow plugs, but the other is them not being allowed to do their job.
That second issue was in part, me being impatient!
Apologies if I'm telling you what you know already, but to start the MJ diesel, you need to turn the key to the first position (when all the warning lights show), and wait until the glow plug light goes off before turning further to start the car. In the winter, this can be a few seconds. (I was advised to wait until the fuel gauge had risen all the way before turning the starter to be really sure) . If you start the engine before the light goes out (or even just flick the starter too soon by accident), it will warn you of a glow plug issue when the engine fires up. That 'warning' is stored, so will show up the next two times you start the car, even if you start it 'correctly' those later times. If you start the car three times in succession, having waited for the light to go out, the warning resets.

The second situation could be a failed glow plug. This is 'a pain' to fix, as they are on the front of the engine, behind the turbo etc. The plugs themselves are cheap, and, so long as not over tightened when fitted (only just past finger tight is correct), they are easy to remove. But first, the turbo and related pipework needs to come out of the way, which makes it a longer and more expensive task.

You can see the location of the plugs here https://www.fiatdalys.lt/en/catalog...917M051870/ZFA31200003210975/0/0/0/glow-plugs That view is the front of the engine.

 

[Goudrons]

The glow plug light is also a warning light for a fuel system fault.


If it comes on or flashes while driving, it does not necessary relate to a fault with any glow plugs themselves but a fault within the fuel system somewhere.


It can often flash if the rail pressure isn't what it expects by being a bit low.
High fuel demand (accelerating hard) with gluppy fuel because it's nearly freezing will do it.
Best warm it up gently in winter, the spill off fuel will return around the pump until the engine warms up to give it chance to suck on warm/freer flowing fuel as the pump and the fact it's just been put under high pressure soon heats it up.



Another misconception is the glow plug light at start up.
It's just on a timer and doesn't mean the plugs are working (or hot enough) just because it goes out after a few seconds.
If it's really cold, double switch the ignition and whack the plugs twice.

 

[Herts Hillhopper]

The glow plug light is also a warning light for a fuel system fault.

If it comes on or flashes while driving, it does not necessary relate to a fault with any glow plugs themselves but a fault within the fuel system somewhere.

No mention of this in the owners book... there, it says the generic EODB light (the picture of an engine) will flash if there is a fuel supply/injection issue.
All it says for the glow plug light is that it shows pre-heating is happening, or, if it flashes (along with a message on the digital display ('Check glow plugs'), that there is a fault in the preheat system.

 

[Goudrons]

Yes, I know it's not in the book but it's one of the strange things about OBD2.


On later VAG cars it can also mean a brake light is out!

 

[g8rpi]

The glow plug light is also a warning light for a fuel system fault.


If it comes on or flashes while driving, it does not necessary relate to a fault with any glow plugs themselves but a fault within the fuel system somewhere.


It can often flash if the rail pressure isn't what it expects by being a bit low.
High fuel demand (accelerating hard) with gluppy fuel because it's nearly freezing will do it.
Best warm it up gently in winter, the spill off fuel will return around the pump until the engine warms up to give it chance to suck on warm/freer flowing fuel as the pump and the fact it's just been put under high pressure soon heats it up.



Another misconception is the glow plug light at start up.
It's just on a timer and doesn't mean the plugs are working (or hot enough) just because it goes out after a few seconds.
If it's really cold, double switch the ignition and whack the plugs twice.

This is not correct. The glow plug light just refers to the glow plugs. It will not come on while driving (will stay on if alreaddy on for a fault)
The glow plugs on a modern car are not on a simple timer, they are controlled by the ECU and the length of time on depends on engine and air temperature. The indicator light stays on for the same time as the plugs. You have to wait longer on a cold day and ma not come on at all with a hot engine.


Robert G8RPI.

 

[Goudrons]

Well I've had several diesel cars, but with two Fords and a Jag I had, when the glow plug light flashes and trips into limp, it always related to either an emission or fuel system fault.


Only last week a neighbour asked me about a similar issue with his VW.
Turned out it's a warning for double brake light failure.


You can search both, I'm not making this up!

 

[g8rpi]

Well I've had several diesel cars, but with two Fords and a Jag I had, when the glow plug light flashes and trips into limp, it always related to either an emission or fuel system fault.


Only last week a neighbour asked me about a similar issue with his VW.
Turned out it's a warning for double brake light failure.


You can search both, I'm not making this up!

Err, this FIAT Forum and the OP has a Panda.
I'm guessing here but did both Fords and Jag have the Duratorq diesel?
Volkswagen call it the "glow plug / Engine management light"
http://www.volkswagen.co.uk/owners/warning-lights
So yes on some makes models it can be multipurpose but on the Panda (and all other Fiats I know of) it only refers to the glow plugs and is only an error warning (for failed glow plug) when flashing.


Robert G8RPI.


Robert G8RPI.