Technical Information Request On Engine Warm-up

[Alberto Michelatti]

Dear and kind friends,

I have a quite difficult technical question for you: I have not searched in any other place in internet because I'm sure that this is the best place.

The question is: what is the best strategy to warm-up my car engine (Toyota Avensis sedan automatic, 1.8 VVT-i, engine code "1ZZ-FE")?: with the cold and wet winter that there is by me (I live in the Alps, italian side) some mornings I find my windscreen and other glasses covered by a often full frozen hoarfrost; the user manual says not to warm-up the engine with the car steady (mainly for enviromental protection reasons, I think), starting instead suddently with a calm drive; this is surely not a problem when the hoarfrost there isn't but, otherwise, I have two possibilities:

1) I can wipe away the hoarfrost whit a plastic scraper, but I don't like at all this idea because the scraper tend to scratch the windscreen (on my previous car a series of quite imperceptible by day scratches have formed, and these was quite disappointing in night drive with other cars headlamps lights hitting to) and, above all, the hoarfrost tend to reform in few hundred meters of drive (very dangerous into road traffic!);

2) I can start the engine and let it run at choke idle for few minutes, regardless of what Toyota user manual says; so, I made two separate tests in two different mornings, both with a temperature of about -5/-7 °C:

a) I started the engine with the A/T lever selctor in "P", with the engine idle starting from about 1900 rpm to finally reach about 1100 rpm, and it employed about eight minutes to produce the heat necessary to defrost the windscreen;

B) I started the engine with the A/T lever selctor in "P" and, after few seconds, to give engine some load and improve warming, I shifted in "D" with the car steady thanks to the handbrake pulled: the engine idle suddently falled down from about 1900 rpm to about 1000 rpm: it employed barely noticeable fewer time to warm-up;

I also found in the user manual a series of recommendations on how to preserve the life of the catalysators and, in them, a recommendation says not to let run the engine at idle speed (with engine already at optimal temperature, I think), with the car steady, for more than twenty minutes.

So, the main question is:

- risk I to damage the engine or one of the two catalysators warming up the car engine at idle? five or six minutes of cold idling are already too much?

- does exist an official Toyota tech paper wich explains for how many minutes at the most is possibly to warming-up the engine with car steady without any mechanical damage, depending by the external temperature?

- for my couriosity, the warming-up with the shift lever in "D" is completely wrong? could it overheat the automatic transmission fluid, with about -5/-10 °C also?.

Because of the drive-by-wire throttle of my car I think that it would be however electronically self-protected against driver abuse and, in my opinion, I think that the engine would probably shut off by its own or the engine yellow warning light would turn on if some mistake is made.

Thanks to everybody for every possible tip and, naturally, happy new year to you all worldwide!

Cheers, Alberto.

P.S.: I'm not sure I'll can reply you daily, so excuse me for this (and for my bad english too)... thanks!

[Leeky]

I started the engine with the A/T lever selctor in "P" and, after few seconds, to give engine some load and improve warming, I shifted in "D" with the car steady thanks to the handbrake pulled: the engine idle suddently falled down from about 1900 rpm to about 1000 rpm: it employed barely noticeable fewer time to warm-up;

Wo wo wo...dont do that! That doesnt sound like a good idea at all.

Just start the car as normal and leave the heater on to defrost the windows.

Forget all that rubbish about the catalitic convertors....they will be fine.

Dont worry about it

[Kelvyn]

If you intend keeping the car for some time it might be worth looking at a pre-heater. Something like http://www.webasto.com/products/en/3115_3422.html

Cost is I believe around 1000 Euro.

[Alberto Michelatti]

Hi to everybody!

Excuse me if I haven't replied you earlier, but I was still waiting for an answer from Toyota Europe Customer Care (please, don't start laughing... give me a minute to explain...), which, with very kind manners, have gived to me the same answers that you gave me too (Leeky, you really are a guru!), but, now, these answers are Toyota-Europe-Customer-Care official, for all the Toyota Owners.

This are the answers, in relation to the possibility to damage the engine or the catalytic converters warming-up the engine with the car stationary:

"Kind customer, in relation to your request we wish you to inform that you DON'T risk to damage the vehicle. As reported in the manual is preferable to warm-up the vehicle driving at low speed, because besides the engine others components and oils/liquids warm-up too. The engine however can be warmed-up with car stationary for a short time, don't exceeding the twenty minutes time described in the respective instruction, because the converter can overheat; this instruction is valid when the engine has reached the normal operating temperature too, as described in the instructions reported at page 254." (I wish I have translated correctly).

For the italian people: "Gentile cliente, in relazione alla sua richiesta desideriamo informarla che NON corre pericolo di danneggiare il veicolo. Come riportato sul libretto è preferibile scaldare il veicolo procedendo a bassa velocità, in quanto oltre al motore si scaldano anche altri componenti e liquidi/oli del veicolo. Il motore può comunque essere scaldato da fermo per un breve periodo, non superando i venti minuti descritti nella relativa avvertenza, in quanto il convertitore può surriscaldarsi; questa avvertenza è valida anche quando il motore ha raggiunto la normale temperatura di esercizio, come descritto nelle avvertenze riportate a pag. 254."

For Kelvyn: thank you for the Webasto pre-heater fitting advise but, I'm quite sure, it would void the italian "5 years/160000 km warranty" for the Avensis; without this warranty voiding problem probably this cuold be the ideal solution.

However, due to the answers that Toyota Europe have gived to me, I'll warm-up the engine with the car stationary for the minutes necessary to defrost the windscreen.

Thank you all!

Cheers, Alberto.

P.S.: I'm not sure I can reply you daily, so excuse me for this (end four may bed englisch to).

[Alberto Michelatti]

Hi!

This morning I have discovered an interesting thing!

Do you remember my problem of defrosting the windscreen while warming-up the engine with the car still? Using the "windscreen defrost button" (that is on the right of the "auto" one, with the yellow light), with an external temperature of -5÷7 °C, it took about eight minute to defrost well the windscreen.

A thing that I have noted only this morning is that, even with low external temperatures (~0÷2 °C), the compressor of the air conditioning system is activated (I suppose to dry the external air incoming and de-mist the windscreen, in normal conditions), and so the green "a/c" button light (that I just haven't noted until today) is on.

So, to do a trial, I have manually switcheded off the "a/c" button and, with an external temperatures of +1 °C, you guess a little, it have taken about the half the time, so about 4÷5 minute to defrost the windscreen well.

Believe me, I'm VERY happy of this discovery!

I wish that this information could help someone with my same windscreen-defrosting-at-low-temperatures problem.

Friendly,

Alberto.