Erratic Revving

[Kingscurate]

Hi gents

First post on an iPhone so apologies.

Just bought an 04 1.8 t2 45 k on clock. On test drive i didnt pick up on an over rev. When cold it shoots upto 2k revs and its erratic when change gear. After a 40 miles journey idle hovers btwn 800 1000 revs and when slowing down it feels like its fighting the deceleration.

Any info? Will introduce myself when on a pc. Its petrol engine

Cheers

[igormus]

Hi gents

First post on an iphone so apologies.

Just bought an 04 1.8 t2 45 k on clock. On test drive i didnt pick up on an over rev. When cold it shoots upto 2k revs and its erratic when change gear. After a 40 miles journey idle hovers btwn 800 1000 revs and when slowing down it feels like its fighting the deceleration.

Any info? Will introduce myself when on a pc. Its petrol engine

Cheers

hello matey

2000 rpm is good at an idle starting;

750 rpm is normal when the engine is hot.

check with MAF sensor first -- it might give a wrong signal to ECU cos of carbon deposits on its sencitive element.

cheers/Igor

[alan333]

04 1.8 t2 45 k on clock. On test drive i didnt pick up on an over rev. When cold it shoots upto 2k revs and its erratic when change gear. After a 40 miles journey idle hovers btwn 800 1000 revs and when slowing down it feels like its fighting the deceleration.

My 05 plate 1.8 revs to around 2000 rpm when cold and therefore it tends to try to pull you forwards when moving slowly. However on mine it's only for a few minutes/a couple of miles and then idles at around 800-1000rpm. If yours takes 40 miles to calm down the there's something not right.

[Kingscurate]

Thanks for the replies.

I wouldnt say it takes 40 miles to calm down, just that after such a journey it was revving at 1k. Thats with headlights on and aircon. Now yesterday went on a 3 mile journey and at lights it was revving at 600rpm idle, which doesnt seem right. Never had an avensis before so some cars do behave differently to what you are use to.

I got a 12 mth warranty, if any use, so hopefully wont have to fret about a bill, but just want some guidance first.

Mpg isnt affected as i worked out im doing 42mpg, in car computer 41.5(if this was relevant)

Many thanks

[igormus]

Thanks for the replies.

I wouldnt say it takes 40 miles to calm down, just that after such a journey it was revving at 1k. Thats with headlights on and aircon. Now yesterday went on a 3 mile journey and at lights it was revving at 600rpm idle, which doesnt seem right. Never had an avensis before so some cars do behave differently to what you are use to.

I got a 12 mth warranty, if any use, so hopefully wont have to fret about a bill, but just want some guidance first.

Mpg isnt affected as i worked out im doing 42mpg, in car computer 41.5(if this was relevant)

Many thanks

1900 - 2000 rpm are OK for cold starting (without A/C)

730-750 rpm are OK for hot engine (without A/C)

It is understood when A/C is ON even on idle -- the rp, are normally rise.

do not be concerned. the badly when rpm are below 1500 at cold idle.

cheers/Igor

[closchkutza]

Hi gents

First post on an iphone so apologies.

Just bought an 04 1.8 t2 45 k on clock. On test drive i didnt pick up on an over rev. When cold it shoots upto 2k revs and its erratic when change gear. After a 40 miles journey idle hovers btwn 800 1000 revs and when slowing down it feels like its fighting the deceleration.

Any info? Will introduce myself when on a pc. Its petrol engine

Cheers

The behavior of the engine is normal.

Mine starts at 1800-1900 rpm at 25-27 degrees celsius ambient temperature.

When the engine is heating up, before reaching the half way point on the engine temperature scale, it will idle at 1000 rpm, without consumers.

Hot idle, without any consumer is at 650rpm. Very nice balanced engine this is.

Hot idle, with AC ON is at 800rpm. The AC compressor is not working all the time, so when AC is on you will notice that the engine speed varies between 650 and 800-850 rpm. This is normal, since the dropping/increasing of the engine speed is matching the AC compressor status OFF/ON.

Hot idle, with lights ON is at 750rpm(almost 800).

When the car is moving slowly but the clutch pedal is pressed the engine idles at 900-1000rpm. Only a few seconds after stopping the car the rpm drop to 650rpm (if no consumers are ON) or to ~800 rpm if AC/lights are ON. This is a feature, not a bug.

Also, after driving out of the city for a longer distance, at the first stop of the car the engine will idle for a longer time at 1000 rpm(~10-15 seconds) even without consumers and only then it will drop to the normal speed.

[Kingscurate]

Clothcuska

You have put into words, the exact description what the engine is doing. So the hot idle and so forth, because it was dropping from 1000rpm to 600ish rpm i thought there was a slight malfunction. Im happier now that someone knows exactly whats going on.

When slowing from Mway speeds to braking, there seems a bit of an over rev of the engine as if fighting the braking action is this normal? And when changing gear if i dont release the clutch a few secs before changing gear the engine revs increase is this normal?

Cheers everyone

[closchkutza]

When changing gears (in a normal way) the rpm either stays at the value prior pressing the clutch either increases by 100-200 rpm. This is the normal behavior. With the clutch pressed the rpm starts to decrease after ~0.5 seconds. This is the normal behavior and it is made that way so after changing gear the engine will not have to increase its speed from the idle value. I have learned to correlate the gear changing with the engine behavior so that i`m using this "lag" in engine decelerating without the engine speed dropping to idle(for example, accelerate to 3000rpm in second gear, press clutch, change gear, depress clutch, engine speed is ~2200rpm in third gear but without it dropping under 2000 rpm).

If the increase of rpm or the elapsed time between pressing the clutch and the engine starting to decelerate are bigger then there might be a problem, somewhere.

What do you mean over rev in case of slowing down from Mway speeds? You mean that you press the clutch pedal and the engine speed increases? If that, by what value and for how long?

Also, from what i have noticed, this engine under engine speeds of 3000 rpm has a weak engine brake capacity. It`s the only car in which i can remove my foot of the accelerator in first gear at 2400 rpm, without pressing the clutch and not get a "bite" of the steering wheel.