2009 1.33 vvti

[Lovecars]

Hi all 

I have a yaris 1.33 dual vvti 

EML light came on

When put on the diagnostic it read the camshaft sesnsor has an issue

I took the camshaft sensor out gave it a good clean and back in the light went off for abit then came back on

But when i took to mechinec he said it may need timing chain car drives fine but at around 3000rpm it make a light metalic noise soo what do you guys think?

[FROSTYBALLS]

Welcome to Toyota Owners Club. 

How many miles?

Moved to the Yaris club.

[Gerg]

Your mechanic's reasoning is sound, this is a problem across manufacturers, and is usually attributed to poor oil change history and/or high mileage.

The cam chain could almost be likened to a bicycle chain, for simplicity.  The pedal crank gear is the camshaft, the back wheel gear is the crankshaft.  The rear gear turns exactly twice as often as the front one does. (In reality the drive/driven gears are back-to-front in this description, but that doesn't matter here).  Both gears have sensors monitoring them.  If the gear's sensors no longer synchronise exactly like they should (they either do or they don't, there is only two choices), then the ECU's logic has been programmed to consider the sensor is giving false information, and the EML is lit.

But if the sensor is fine, then there is the other possibility;  the length of the chain has changed slightly ('stretched', i.e. worn), then that would cause the the same 'false' sensor information to be given.  If that is the case then the symptoms will slowly get worse as the chain slowly wears more over time, and the ECU considers the information to be implausible more and more often. 

Poor engine oil quality seems to wear the cam chain before most other parts, or at least, this is where the engine throws an EML through mechanical wear, first.

[Lovecars]

The car has done 87k 

So do you recoment i do a full service on the car as the oil is low and abit grogy and im sire its the wrong one

[FROSTYBALLS]

When was it last serviced - in time and miles?

[Lovecars]

Just now, Lovecars said:

The car has done 87k 

So do you recoment i do a full service on the car as the oil is low and abit grogy and im sire its the wrong one

39 minutes ago, Gerg said:

Your mechanic's reasoning is sound, this is a problem across manufacturers, and is usually attributed to poor oil change history and/or high mileage.

The cam chain could almost be likened to a bicycle chain, for simplicity.  The pedal crank gear is the camshaft, the back wheel gear is the crankshaft.  The rear gear turns exactly twice as often as the front one does. (In reality the drive/driven gears are back-to-front in this description, but that doesn't matter here).  Both gears have sensors monitoring them.  If the gear's sensors no longer synchronise exactly like they should (they either do or they don't, there is only two choices), then the ECU's logic has been programmed to consider the sensor is giving false information, and the EML is lit.

But if the sensor is fine, then there is the other possibility;  the length of the chain has changed slightly ('stretched', i.e. worn), then that would cause the the same 'false' sensor information to be given.  If that is the case then the symptoms will slowly get worse as the chain slowly wears more over time, and the ECU considers the information to be implausible more and more often. 

Poor engine oil quality seems to wear the cam chain before most other parts, or at least, this is where the engine throws an EML through mechanical wear, first.

So do you think i should change the oil first??

[Lovecars]

4 minutes ago, FROSTYBALLS said:

When was it last serviced - in time and miles?

I have got no idea i think probs 3 years ago lol

[FROSTYBALLS]

3 minutes ago, Lovecars said:

I have got no idea i think probs 3 years ago lol

That could be a contributory factor if it has a timing chain issue. Ideally service intervals should be every year/10,000 miles.

[bathtub tom]

2 hours ago, Lovecars said:

Hi all 

I have a yaris 1.33 dual vvti 

EML light came on

When put on the diagnostic it read the camshaft sesnsor has an issue

I took the camshaft sensor out gave it a good clean and back in the light went off for abit then came back on

But when i took to mechinec he said it may need timing chain car drives fine but at around 3000rpm it make a light metalic noise soo what do you guys think?

I had this problem, albeit not on a Yaris, and to prove the sensor was faulty I swapped the camshaft and crankshaft sensors (they were the same part). The fault code then moved to the other sensor. Replaced the faulty sensor, problem fixed.

[Gerg]

+1 to trying out what Bathtub Tom says above. 

But, If it is camchain wear, then doing an oil and filter change might make a difference for a very short while (days, a few weeks??) as the new oil will be thicker than the old and 'bulk up' the clearances a bit, but the wear will still be there.  To replace the camchain, the driver's side of the engine has to come off, so expensive.  Go to that option last.  Why not get an oil change anyway?  The old oil is shot.

[Lovecars]

1 hour ago, FROSTYBALLS said:

 

Tbh i just want the EML to go off tbh