Car starting too quickly on cold mornings? Mondeo Mk5

[FluffyBunnyFlipFlops]

Hi all, I've just bought a 2016 Mondeo Titanium and I'm loving driving it. There's just one weird thing about it that I hope you can help with. On cold mornings, when I press the Start/Stop button, it only gives the glow plugs about a second to heat up and then tries cranking the engine. It then takes two or three lumpy turns before starting. It feels like that whatever tells the engine to start cranking is doing it too soon. I've never know a diesel car in the past to need only one second of heating before turning over on a cold morning, unless Ford have some magical way of heating the cylinders quickly and there's some other reason it cranks a few times before bursting into life.

I appreciate any help you can provide, guys.

Cheers,
Richard.

[TomsFocus]

Does the outside temp sensor read correctly?

Common rail diesels don't need much glowplug time at all.  Totally different to the old IDI diesels.  However, if it's starting lumpy, chances are the plugs might be past their best by now.

[Tizer]

Direct Injection Diesel Engines do not need Glow Plugs to start except when the temperature is well below zero although modern ones may use the Glow Plugs for Emission purposes to comply with current legislation.

My old Rover Diesel only had Glow Plugs on three of the cylinders and I never had to give it a pre heat except on the few mornings when it was seriously cold, even when it had done 280,000 miles. That car had a Distributor Pump as well, not a higher pressure Common Rail one.

[rd457]

I've heard that in some diesels the vehicle will turn on the glow plugs before you actually try to turn on the engine (when you unlock, or put the key in the ignition, or whatever), in anticipation of the engine being started, to help achieve a faster start.

[TomsFocus]

11 hours ago, rd457 said:

I've heard that in some diesels the vehicle will turn on the glow plugs before you actually try to turn on the engine (when you unlock, or put the key in the ignition, or whatever), in anticipation of the engine being started, to help achieve a faster start.

There's no need to turn to ignition first with push-button start.  That's the problem here.  On an older car most of us did it out of habit, leaving the key at 'ign' for a second or two before starting.

With push button start, you just press the button once with the clutch down, the PCM preheats for maybe 1 second (temp dependent) and then turns the engine over without having to press the button again.

You can turn ignition on first if you like, by pressing the button without pressing the clutch, but that's a bit of a faff!

Glowplugs aren't triggered by an unlock (on Fords at least), they'd be cold again by the time you get round the starting.  However, on petrol models (Mk3 Focus/Mk7 Fiesta), the tank fuel pump runs when unlocked or door open, which you may be thinking of.

[DaveT70]

Yep, glow plug light will hardly stay on at all unless the outside temperature is below 0 degrees

[rd457]

10 hours ago, TomsFocus said:

Glowplugs aren't triggered by an unlock (on Fords at least), they'd be cold again by the time you get round the starting.  However, on petrol models (Mk3 Focus/Mk7 Fiesta), the tank fuel pump runs when unlocked or door open, which you may be thinking of.

No I wasn't thinking of that. It's something I picked up from reading the wikipedia article on glow plugs recently.

Quoting:

Quote

Newer systems automatically activate the glowplug(s) before the engine is started and have a quicker warm-up time.

and

Quote

For older vehicles, the driver needs to activate the glow plug for approximately 20 seconds before starting the engine. This is achieved by leaving the ignition switch in the "on" position, and only moving it to "start" once the glowplug has finished pre-heating the engine. Once the engine is running, some cars continue to use the glowplugs until the engine has reached its operating temperature, in order to reduce the diesel exhaust emissions. Similarly, some engines re-activate the glowplugs if the temperature of an engine under light loads reduces below a certain threshold, in order to improve the efficiency of the engine.

Many modern engines automatically activate the glowplugs when the operator unlocks the vehicle or opens the door to the car, thus simplifying the process and shortening the waiting time the operator has to wait before the engine will start. In addition, the time needed to pre-heat the engine is typically 6-8 seconds.^[2] Some vehicles include a warning light on the dashboard that extinguished once the engine was pre-heated.

[TomsFocus]

7 minutes ago, rd457 said:

No I wasn't thinking of that. It's something I picked up from reading the wikipedia article on glow plugs recently.

Quoting:

and

Don't believe everything you read on Wikipedia.  I'd disagree with quite a bit of that quote.  

I've never needed anywhere near 20 seconds of glowplugs on older cars, or 6-8 seconds on newer stuff!  It is literally a second or two on common rail.

I suspect it may have been written for commercial truck engines or a much colder climate.  

[unofix]

Just to put my bit in ...

In the 3 years I've had my 2.0 Ecoblue I've only actually seen the glowplug light active twice. Once when it was -3.0^oC and once at -7.0^oC. Both times the light was on for less than two seconds.

Even on very cold days of 0^oC I've not see the light on, and the engine always starts first time in under 5 seconds.

Except for tomorrow when it won't start now that I've said that 🤣

[Tizer]

That Wikipedia article was written for a time when a lot of Diesel engines where Indirect and they did need a lot if time on the Glow Plugs to get them started. My fathers old Taxi needed at least 10 seconds most of the time.

As I said before, Rover thought that Glow Plugs were so unimportant that they only fitted three to my engine and they did not come on when the car was opened, nor did they need activated 99.9% of the time.