I'm just after a bit of clarity on the glow plugs.

I believe that my 2010 (built late 2009) has 11v glow plugs which operate from a simple relay which the ECU activates.

I believe that the Freelander may activate them without even during the dash light on cold mornings and keep them running for a few seconds after starting (is this true? What temperature do they start without the dash light?)

I've then heard when the temperature gets very low (below 0?) That the Freelander will then show the dash light for the glow plugs and there will be a short delay between pressing the button and the car actually starting. Is this true? What temperature should the dash light for the glow plugs show?


My reason for asking these questions is that our Freelander suddenly becomes more difficult to start below a certain temperature. When it roughly dropped below zero the Freelander simply would not start, jump leads could just about get it going but it was a struggle.

A new battery improved things, now when the temperature drops below zero it will start but turns over a fair bit before starting.

My plan is to replace all the glow plugs when the weather is warmer. Probably when I do the next service in June so I can so the fuel filter at the same time.

However I'm concerned that it might be the relay instead as we have never seen the glow plug dash light come on. Even when the dash was reporting -3*C.

My other thought was the temperature sensor that the glow plug circuit uses. Does anyone know which one it uses? And if you can monitor the temperature of this from the Autel?

Is there any useful information such as live data for when the glow plugs are on, in the Autel app?

Thanks!

Here is a link to my thread on glow plugs, with info from Alex and others regarding temperatures amongst other things. I can not help with regards to which temp sensor is used by the ECU.

https://www.freel2.com/forum/topic37636.html

Hope this helps

Richard

Mine also doesn't show a glow plug light, with dash displaying -2°C, however it seldom gets lower than that where I live, so I don't know if it needs to be say -5°C before the light comes on.

As for sensors, the ECM would normally use the coolant temperature sensor to determine engine temperature for starting, so unless the engine is below whatever threshold the ECM puts the light on, the light won't come on.

It's pretty normal for glow plugs to be energised on a cold start, even if the ECM doesn't show the light, as it's designed not to alarm the driver, but the ECM controls the plugs in the background, simply to improve cold running performance.
I'm sure they'll actually run for some time, which would explain why they seems to fail so quickly, even if it appears to the driver that they never come on. Hyundai Ioniq 5 Ultimate. The family car.
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I recall a discussion a while back about glow plugs and I thought back then, Ive never seen it light up on the dash. Therefore I decided to make the effort to look for it when its cold, so, about 2 or 3 weeks back it was very cold and frosty, so I went into the garage to check, I saw the glow plug light !!

Thing is, I cant remember the temp, but what I can say is it must have been at most -3 possibly -2 (we are talking Durham not the North Pole)

Not sure what you mean Nodge about "failing so quickly" . . .had the car 5 years now, as far as I am aware at 168,000 miles its still on original plugs, not 100% positive, but I believe it is. But I am 100% on the fact it still has original clutch.  2017 SEAT Ateca 4drive 2.0 xcellence (May 2022 -
2007 HSE with HST bodykit in Zermatt Silver 169,700 miles (dec 2016 - May 2022 )
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