Car Maintenance

It's probably the front tires out of balance....do you rotate your tires regularly...?

Read the first post again. He's stopped when it's shaking.

So it's idling too low....change the air filter, and fuel filter....spray some carburetor cleaner on the throttle body...

You might try www.yarisworld.com. First, take it somewhere (like AutoZone, Advance, or O'Reilly in the U.S.) and see if any engine codes come up. Could be dirty/fouled throttle body and several other things.

BTW, 10W40 seems pretty heavy for this little engine.

So, what grade of oil would you suggest to use?

Thanks.

I'd use what the owner's manual says to use. Just quickly looking over the Yaris site, I think I saw 5W30, but the owner's manual is the final word. (My neighbor's new RAV4 calls for 0W20 or 5W20. 10W40 and 20W50 may not have the latest/highest/recommended API rating.)

I agree with following the owner's manual, but I can't imagine wrong oil grade would cause the symptoms described.

Agreed, this started as BTW .

Yeah, years ago I used to commute to work from the Central Coast to North Sydney.

Bumper to bumper at 120kph on the freeway in fog. Sh*t happened frequently.

I transferred to Perth.

could be the dead cat you ran over..

Agree. Most people just replace the plugs and not the plug wires. Today's spark systems can run as high as 150Kv, in the old days it was more like 50 Kv.

I also agree with tcm on this. Sounds like plug wires and/or the coil pack/SCM.

If they've never been changed, all the more likely this is the culprit.

Can't pour water on the exh. man.

Enshrouded by heatshield.

Stu.

Are you sure it's not a Cavalier?

Air Bypass Valve may be sticking and needs to be cleaned or replaced.

Throttle Position Sensor may be dirty or faulty.

Engine Temperature Sensor may be faulted.

Engine Gas Recirculation Valve may be sticking and needs to be cleaned or replaced.

I would start with the EGR valve as it is the easiest to check and replace.

Check if oil level is at acceptable tolerances ( min- maximum). I suspect you overly exceeded maximum oil level. Is there any unusual noise besides the shaking?

It could possibly be a motor mount problem at the point of tarus stall speed.

2007 has OBDII.

Is it throwing any codes in addition to what appears to be a too slow idle speed.

It's summer in Sydney now. Is the shaking concomitant with airconditioning use in the afternoon?

You've changed the spark plugs and put the leads on incorrectly.

Typical symptom of two wires transposed.

Cheers,

Stu.

For me, it may be as simple as too low tick over. 500RPM for such a small motor smacks of that. I would expect 850 - 950RPM myself.

Its certainly not a motor oil problem, assuming quality oil at the right mileages and ONLY OEM filters! But even if not, still most unlikely....

He did not say if the car was in neutral or in drive when it happens, but I suspect drive, and that his automatic gearbox may have a slight adjustment/low oil/wrong oil/water in oil problem, if the tick over is correct for this model of car....

There is still the possibility, that the tick over IS wrong, but correcting it might make the problem worse because of an automatic gearbox problem as well....the box could be "braking" the engine tick over.

But as most modern cars have the tick over controlled by the ECM, there is a possibility that the problems may come from there as well.....

As could bad engine timing due to a broken sensor/connector and engine is running in its "emergency - get you home - mode". Though this usually posts some sort of error for the driver that he needs to get a service/repair....

If it happens when in neutral sitting at a light, then I really must put my thinking cap on!!!

I almost forgot:- ITS NOT TYRES OR WHEEL BALANCE GUYS !!!!

You have a Vacuum leak !

Last time I had a vacuum leak was in a car (much older than 2007, more like 1956, so maybe not comparable), which had pneumatic screen wash, and the vacuum hose occasionally came adrift. You could tell it had happened because the idle speed increased, and there was pre-ignition on switching off. OP's idle speed seems on the low side, as AG said in #22.

Looking at your explanation it seems that the auto box try to lock the box in drive and pull the rev's down to 500, the g-box pump release the pressure at 500 rev's and as soon as it go up pump kick in and pull it down again. I will assume that you do left foot braking when you lift the rev's as you will slam into the car in front of you if you do not. Inside the bottom of the g-box is a filter that may bee need a replacement. Good luck.

i forgot to mention that the Gearbox engage and disengage from traction is regulated by the vacuum sensor on the side of the box with a pipe leading and sensing the vacuum in the inlet mannefold. High vacuum as when the car is idelling will disengage the box and if you press the excelerator the vacuum drop and the g-box engage. If you have a leak in this pipe or the diafram in the sensor is punchered it will stay in g-box engaged as if you want to pull off and pull the rev's down. English is not my 1st language.

You're getting closer.

The vacuum modulator in the transmission could have a leaking diaphragm.

Unusual fault to have tho', in this vehicle.

The vacuum doesn't actually disengage the drive tho.

The engine speed just drops below that point which the torque converter is designed to stall. [Check this yourself-- move the selector lever D--N--R. Feel the clutches take-up?]

Cheers'

Stu.

Last time that happened to me, tranny fluid was sucked up into the inlet manifold and the result was a spectacular plume of exhaust smoke that would make Batman green with envy.

I read it that the shaking was a missfire.

Hence plugwires, etc

ANYTHING could be wrong. Non-closing/non-sealing valves included. Vacuum leaks -- do the brakes work as they were previously? On and on.

We can postulate for the remainder of the millenium and not actually get it right.

[This is getting a bit like the woman asked me the source of a "funny noise" over the phone. I asked "humourous or weird". Lost her!]

Anyway there are thousands of mechanics who will diagnose and repair the vehicle BEFORE serious damage occurs whilst you drive it with its fault.

Will you give us feedback?

Cheers,

Stu.

I'd personally be interested in finding out what actually is/was wrong.

Compare your recommended engine idle speed with your 500 indicated speed. I believe that it should be higher. There should be a device that adjusts that speed by allowing some air to bypass the throttle body. That could be sticking, gummed up. or broken. This is a start, not a sure fire solution. Good luck.

It is also not a driveshaft out of balance.

Hi it most likely is your pilit baring. Have a Transmissions shop look it over.

Im sorrry baring is not the right wored the right wored is Bearing, it is back behind the pressure plat. Like in told you take it to the Transmission shop. Good luck.Hope you get your car fix.

Welkum to da fourarm.

Seriously, it's always good to see some new members having a go.

Now all we need is the OP (original poster) to jump into this discussion with some follow up observations. Might be waiting a while.......

Nah! Waste of time.

S.

The spell checker on CR4 could help you write in a better manner...It won't fix everything, but it will alert you to the words not in the dictionary....I use it always and I am a reasonable speller, but typos are also found!!

Thanks in advance for your understanding.

Many thanks, well put.

I hope you get through to him, but I really doubt it.

He joined on the 30-1-2015, he has already upset a lot of people......if he does not change radically.......

Forecast;- in one year he will be LONG gone....

Thank you, appreciated.

It's an automatic transmission. Automatic transmissions do not have pilot bearings or pressure plates.

meddy from Sydney, Australia, please comment on the suggestions. we do not know if you have an air con, have you tried something, did you sort it out, did you take it to Toyota?

The Engine Management System adds extra fuel when the engine is cold and cuts it back once warm. ( choke ) To get the fuel mix right the EMS relies on a number of sensors. The throttle position sensor is prone to wear, the oxygen sensor is prone to burn out other sensors are prone to mechanical damage and the problem may not even be related to the EMS.Sucking a small amount of air affects fuel mix and causes these symptoms.Spark system breakdown causes these symptoms.Gearboxes are now part of the EMS and there can be sensor problems there as well. My Verada kept trying to change into 1st whilst at speed - faulty throttle position sensor.Please reply to some of the posters' questions to get a better answer.Jim

I know that you have replaced your plugs ~11,000km ago, but I would pull them and check them for gap and carbon build up. Did you use the same make /rating of plugs as the originals? Champion plugs had a poor reputation for a long time, NGK are very good, likewise Bosch.

Some further thoughts....

If your idle revs are too low it will idle roughly

If you have an induction air leak after the air metering you will have increasingly rough idle. this could be from loose manifold, manifold gasket, split hose, worn and leaking throttle shaft.

blocked PCV valve.

Faulty inlet air metering device (MAP/Flow) sensor.

You can use a length of hose as a sort of stethoscope to listen around the induction hoses, manifold etc for air leaks

As long as we are on the subject; I remember "I" before "E", except after "C", or when sounded like "A", as in neighbor and weigh.

Can you help me with the correct uses of ":", and ";"? Thanks.

Many, many thanks for all your suggestions.

This rough idling was there even before spark plugs were replaced.

Also maf sensor has been clean. The only thing that is not yet clean is the throttle housing.

Is it a very technical job to be done?

GA for detailed explanation. Fingers crossed for OP that it works! Hopefully he'll let us know.

Like it!!!

Thanks for the reply, but I think the OP's problem may be more than that. If the timing belt-chain-gears have worn, the camshaft will become retarded. That will lower compression. And no amount of cleaning will restore that compression.

An alternative to the posted method would be to remove the spark plugs, pin the throttle wide open, and hit the air intake with a pressure cleaner. Follow up with plenty of shop air. Then turn the engine over with the spark plugs out by hand a few times, then with the starter, then install the plugs, close the throttle and fire it up.

That should start some nasty letters.

Is that an alternative cleaning method, not meant to help with problem caused by worn camshaft drive hence retarded camshaft? In any case that would not affect the ignition timing, only the valves, and it would have to be pretty severe to cause a problem. I once worked on an engine where it was one tooth out on the camshaft pulley (toothed belt drive) but it appeared to run normally.

I think I prefer your first method for cleaning!

No actually the alternative cleaning procedure would work for cleaning the manifold on most any engine where the runners are not so twisted as to prevent the pressure washer from hitting the walls.

The retarded can timing by itself would not be too bad if the ignition timing is set by the crank. But if the ignition is set based on the camshaft position, as with a distributor, then the ignition becomes retarded as well.

The worst case I ever had was a Toyota Supra that needed a timing belt. After replacing the belt, the car came back with a complaint of no power. I pulled the plugs and found they were originals. I replaced them because the car had 98,000 miles. That made no difference. So I checked to see if the timing had jumped. Sure enough it had jumped one tooth. Well the AH that just put the belt on must have left the tensioner loose right? I pulled it back down, and the tensioner was tight still. Tightened it a little more, and sent it on its way. Two weeks later same thing, no power, and the timing is one tooth off. NAPA replaced it and never another issue.

The retarded can timing by itself would not be too bad if the ignition timing is set by the crank. But if the ignition is set based on the camshaft position, as with a distributor, then the ignition becomes retarded as well.

That's correct if the ignition timing is set up, then the wear occurs, and nothing is done. But the distributor can easily be re-adjusted to the correct firing point, and I was assuming that would be done. With a 2007 car I would guess ignition timing is controlled by the engine management computer, usually via a trigger on the flywheel, so it's not an issue.

I think the only issue remaining is, What happened to the OP?

Yes, it happens all too often. Speedy00002 with a Chevy cavalier didn't get back to say whether any of the many suggestions he'd received solved his problem.

OP came back as Meddy, it seems. He was back on 61. Need time to perform that cleaning operation

Yes, you're right. Just hope he keeps us posted.

Meddy, what does the car do in neutral?