Yaris juddering

[1.3yaris]

hi all. I've had my 1.3 2006 petrol yaris for nearly 18 months and its been faultless mechanically, but today I was driving along at 30mph in 5th gear and it kept juddering. if I keep the revs high it seems fine its just when I get to a constant speed in a high gear, i also noticed when I stopped it was idling lower than normal about 500rpm and actually cut out taking a couple of attempts to start it up, it has always sat low say maybe 600-700rpm but never cut out. Any help would be appreciated

[flash22]

Just change down !!! 3rd or 4th at 30 mph is about right, it will struggle at low rpm in 5th due to the low ratio 0.8 - 0.88 IIRC you will cause damage in the long term

Also being in 5th at 30mph means you will not have as much control over the car, in 3rd it will be easier to maintain speed and accelerate out of danger or to a higher speed limit eg 30-40 or 30 into a national speed limit

[1.3yaris]

Its never been a problem before and juddering like its misfiring

[flash22]

What's the mileage ? When was it last serviced ? When where the plugs changed ?

 

tbh 30mph in 5th you are just labouring the engine

[1.3yaris]

95000 miles, serviced 1000 miles ago. I don't know about the plugs I've not put any in since I've had it in 18 months and 12000 miles, i was thinking about getting some after work tomorrow and trying that.

[Madasafish]

Plus, air filter, MAF sensor  - all likely.

Never use 5th under 40mph...

[Stevie J]

I'd say it was a dirty or faulty Mass Airflow sensor (MAF sensor), which is in the throttle body behind the airfilter box. When these sensors go faulty or get dirty, the car will run erratically, and not idle properly - often the orange engine shaped Malfunction Indicator Light on the dashboard will come on and a fault code stored (the MIL). It is difficult to clean the MAF sensor and they are fragile inside too, and it may be that the MAF must be replaced altogether. They will be likely to be expensive too.

[donkeychomp]

I say give the old girl some grief with your right foot. Cars need to be thrashed sometimes! 30mph in 5th gear is not going to help anything at all, quite the reverse.

[flash22]

The 1.0 and 1.3 like to rev, the 1.33 even more so, open it and let the vvti loose

30mph in 5th is a bit like getting a piggyback ride from an asthmatic up a steep hill

[mrfixer]

Sounds like a misfire under load to me. I'd be looking at new sparkplugs (since you don't know when they were last done) plus a careful inspection of ignition components.

[scannerman]

On 6/21/2020 at 6:07 PM, flash22 said:

Just change down !!! 3rd or 4th at 30 mph is about right, it will struggle at low rpm in 5th due to the low ratio 0.8 - 0.88 IIRC you will cause damage in the long term

Also being in 5th at 30mph means you will not have as much control over the car, in 3rd it will be easier to maintain speed and accelerate out of danger or to a higher speed limit eg 30-40 or 30 into a national speed limit

Your car should accelerate smoothly from 30mph in 5th, so I suspect you may have a problem. I have a six speed and will cruise at 30mph in 6th and will smoothly increase its speed without changing gear.

If you want to clean the MAF, its easily taken out, two bolts, undo the electric connector and it removes. You must use MAF cleaner, it leaves no deposits left when dry, any cleaner deposits left on it will affect its operation. If the car was serviced 1K miles ago then plugs and filters should have been changed.

As its done 90K miles, I would look at the throtle body, these crud up over time and need cleaning out.

All these things are on YouTube if you choose to try them yourself.

[vanadeo]

I'm intrigued as to why such a high gear is used at such low speeds.. I tend to keep in as low gear as possible when slow. The amount of times I have had to brake suddenly cos of some idiot pulling out on me or narrow country road bends, someone comes flying round the corner.. Get better engine braking and all that, also for a 1.3 it responds better in a lower gear at low speed when I need it to shift quick.. Not like mi old 1.8L Corsa Could go uphill at 30 and accelerate in 3rd and it would go like a rocket xD... My 1.3 yaris dies on the same incline in 3rd, I am in Sheffield though.. The roads are pretty crud here.

Anyway a good service should help it.. Surely shouldn't just cut out if cruising in 5th at a low speed. Be interested to know and hope you sort it out dude.

 

 

[flash22]

9 hours ago, scannerman said:

Your car should accelerate smoothly from 30mph in 5th, so I suspect you may have a problem. I have a six speed and will cruise at 30mph in 6th and will smoothly increase its speed without changing gear.

If you want to clean the MAF, its easily taken out, two bolts, undo the electric connector and it removes. You must use MAF cleaner, it leaves no deposits left when dry, any cleaner deposits left on it will affect its operation. If the car was serviced 1K miles ago then plugs and filters should have been changed.

As its done 90K miles, I would look at the throtle body, these crud up over time and need cleaning out.

All these things are on YouTube if you choose to try them yourself.

 

yaris1.3 is the OP, not me

 

 

[1.3yaris]

After taking the yaris to a local garage they found no fault codes and asked if I'd filled up at any supermarkets. I had just put a tank of fuel in at asda in Norwich just before problem started. Now after another 3 full tanks of  premium petrol and some injector cleaner gone through the car the juddering has gone as if by magic, lesson learnt steer clear of **** petrol.

 

[flash22]

Well that will do it, modern engines do like a higher octane fuel

[mrpj]

Fuels for road use in the U.K. have to comply with laid down standards. I've almost always used supermarket fuel, unleaded 95RON. Occasionally dipense some standard 95RON Shell.

If the fuel wasn't contaminated in any way e.g. water, that shouldn't have caused any issues. I think if there was an issue, Asda would have been inundated with complaints.

Good that it's now running well though.👍