Ask Xulfiqar - An Automotive Encyclopedia

[TypeA]

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[Xulfiqar]

mechanical valve timing is necessary to be dead on perfect to get proper compression from cylinders.

spark timing is for for proper burn and drivability.

You cannot drive a mechanically mistimed engine by trying to advance/retard the spark timing.

[pwuser150030345585]

Sir, after watching this video don't you think that a mechanically mistimed engine can still drive but not smoothly and efficiently? Although you said this conditionally 'by trying to advance/retard the spark timing'.

[Xulfiqar]

If by driving you mean, car is moving. Then your and my definition of driving are on different planets.

You can have a 2 degree at crank mechanical mistme on an old carburettor engine but cannot do at 10 degrees mistime on an efi with dedicated crank sensor on crankshaft itself.

[pwuser150030345585]

No Sir, I don't mean driving as only the car is moving; but also the engine is idling as in the video.

[Xulfiqar]

A started and spinning engine doesnt mean its good.

You can have a blown gasket, mistimed, low compression, oil burning engine that starts too.

[pwuser150030345585]

Of course, you're right, but to be specific a mistimed engine not only spins and starts but also drives the vehicle though not as efficiently as a correctly timed engine do.

[Xulfiqar]

I dont get your point of argument. Are you implying that people should drive mistimed engines?

if your valve timing is off, your cylinders would not fill properly and the engine will never have its full power output.

[gohar83]

How much citric acid should be used for a cooling system with a capacity of 10 litres ?

@Xulfiqar

[Xulfiqar]

10% by volume means a 1kg of citric acid in 10 litres of water.

[pwuser155913790095]

@xulfiqar how timing is set on 1krfe engine it has a timing chain how to check if timing is not set correctly will it still run?

[saqibhassan95]

@Xulfiqar
Another query related to engine oil
Usually interval recommended by oil or car manfacturer is X miles or X months whichever comes first
So if one has covered less miles and total no of months interval are passed, what one should do?
One can run oil recommended for 3 months upto 6 months?
Personally I don't prefer extending it
Looking forward for your expert opinion

[gohar83]

replaced the thermostat valve and t-valve gasket on my 1HDFTE.
The temp guage now stays exactly where the arrow is pointed.
Between 5th and 6th marking (starting from bottom)
Is it normal? Furthermore plugged in the techstream and the coolant temp reading was 80°C at that time.

[gohar83]

[gohar83]

[Xulfiqar]

Dont drink the youtube lassi blindly as you dont know how an engine works.

If an engine has been cold run a lot - condensation in the engine mixes with oil and depletes the additive pack. This is why engines should reach operating temperature quickly and run hot for a while to steam off and self clean the oil.

Again, dont drink the youtube/google lassi without know how.

[Xulfiqar]

it has classic toyota design with marks on the pulleys and the chain has marks too, If the mechanic assembles it wrong - the engine will either not start (very wrong timing) or have really rough running with a TDC error on check light (1 tooth off)

If mechanic cannot time a toyota engine, he should sell his tools and take up some other profession

[Xulfiqar]

If the needle stays at 5 or 6 mark on that gauge, you are perfectly normal. On older toyota gauges, dont consider the red part at the gauge sweep - its "beyond" the gauge sweep.

If you then note the marking you pointed out - its 45% sweep of gauge.

[brownrose78]

@Xulfiqar bhai,
Recently Radiator shop put such new radiator in my Khyber which does not have drain nut/drain valve in bottom body of Radiator. (I think it is of soe Japanese car)

How can I do acid flush it with tartari and then with baking soda

Do 10% by volume formulae will apply to Baking soda proportion in water too?

[Xulfiqar]

its the same process - but you remove the hose pipe rather than drain tap - make sure to wear gloves to prevent hot water burns.