Yaris 1.0 Problem(S)

[czechhero]

Had a problem with our 51 reg 1 litre Yaris that has got worse over the last few months. It's had what seems like a sticking throttle, ie when changing gear the engine carries on revving even when taking your foot off the accelerator. Even opening the bonnet and manually revving the engine has the same effect, so it's not a sticking cable. A friend suggested a leaking vac pipe but we've checked those and they seem ok, but I don't know if the inlet manifold has a split in it as it's only plastic like most most modern cars. is this a common problem? Can it be superglued back together?

Any help appreciated.

Also the top end has become very noisy, could it be the cam or just a tappet. the motor has 110k on it.

Cheers.

Oh yes, ps, hubby changed oil, filter, air filter and spark plugs today but it's made hardly any difference at all.

[Madasafish]

Sticking throttle MAY be caused by the cold start mechanism not working properly. Has the coolant been changed ? Is it dirty? If so, the idle speed stepper motor which is run by a waxstat thermostat may not be working properly due to a blocked pipe...Read the attachments at the bottom...

Recent engine noise from top end... Has the car had REGULAR oil services with the proper semi synthetic oil and Toyota oil filter? Even if it has , with its mileage it is likely the timing chain is worn. If not, then the chain WILL be worn. Replacement parts# are c £150- £200 and it takes about 5 hours.. The noise comes from the side of the engine with the belts..

# chain guides, chain and possibly chain tensioner

The oilways may be blocked - Oil Control Valve has no filter on the 1.0 so that may need to be cleaned.. An easy job.

Of course, if the oil has not been regularly changed you may also have worn valve guides and the valves need to be checked.. but that is unlikely...

Attachments 3&4 give chain layouts and instruction on installation.

engine pics.pdf

Engine pics1.pdf

[czechhero]

Thank you for your highly comprehensive reply.

I'll get hubby on it straight away, although that last link looks a bit scary!!

Thanks again.