Glow plug relay

[Diesel darren]

Hi 

What is the normal pre-heat time for the glow plugs on a D4D Avensis?

I would expect 10 or 15 seconds but my indicator light only stays on for 1 or 2 seconds max.

This time seems much too short to do any good as I get a significant amount of blue smoke when starting from cold.

[paul9]

It's normal for what you described. I believe that there is a secondary heating period at a lower voltage and that is common in glow plugs in modern diesels. The secondary heating doesn't register on the dash lights. I am not 100% certain on this, but it is what I have picked up from other people's comments since I have had my Toyota. Also, is your blue smoke happening for a significant time after the engine finishes cranking and catches to run? Does it take a long cranking time before it catches, especially in the cold?

[yossarian247]

Yes as above, totally normal. Common rail direct injection diesels don't rely on glowplugs anywhere as much as old IDI diesels, and only really need them for starting once the temperature drops below about 5C. Above that most common rail diesels will start quite happily even with all 4 glowplugs dead/disconnected. 

[Reman]

I have almost identical issue.

Glow plugs wren replaced last winter, which improved things but I was still not 100% happy.

Now its dropped cold again, its getting difficult to start.

My glow light varies from 1-2 seconds, down to half a second, which I'm sure is not long enough.

What I cant work out is if this is telling me something?

I'm sure the relay is just a plain one, not timed, so I wonder what other electronics to sensors are controlling the period that they stay on for?

And if so which/what/why?

Cheers

[yossarian247]

I think glow plugs are a red herring here. The suction control valve is a more likely cause of poor cold starting on the d4d engine. 

Although the glow plugs would stay on for several seconds on old indirect injection diesels this just isn't necessary with common rail direct injection. I've owned a variety of VW TDi, Peugeot HDi, and Toyota D-4d cars and the glow plug light staying on for at very most a couple of seconds is perfectly normal. 

There's quite a few threads on here about the issue with SCVs if you search. Eg

 

[Aftab Ahmed]

Hi,I've recently purchased a 2018 toyota avensis 1.6 d4d,noticed heater light has not come on when I turn key in ignition,but the vehicle starts first time. Just wondering is this normal in summer in months?Have owned diesals in the past,but never experienced this before.