2sz-fe engine noise 2008 Yaris

[vanadeo]

Hey back again.

Took yaris to garage today for the mechanic to have a listen to and he reckons that it doesn't sound bad for a 12 year old car. 84K on the clock, and I am not convinced this sounds normal.

Mate of mine thinks it could be the timing chain tensioner thats naff, told another mechanic and he says it'd be best to bang a whole replacement kit on there which I imagine could be anywhere in the region of 400-500 quid. :/. It Idles a bit low as well I'd say below 500rpm once its warmed up and sounds worse as well when warmed up.. Can hear the clicking noise when rolling in gear with no gas.

No codes or anything at the moment. All I want to know is, is this normal or is it cause for concern?.

 

[Stevie J]

Mine's a 2006 1.3 - same as yours. The engines on these always seem a bit tappety, mine is the same clicking at idle and I also can hear it driving along. Its valve clearances that need adjustment - these engines dont use hydraulic tappets, so they need to be adjusted manually, Toyota recommend its done at 60K miles. Fuel injectors can also be heard clicking which is pretty normal for these engines too. The timing chain should need no maintenance as long as the oil has been changed regularly every 10k miles, but I dont think your engine is suffering from chain wear rattle. Chain wear often sets an error code in the ECU about correlation in timing issues, which would light up the EML on the dash, but that is not usual unless the chain is very worn and stretched,meaning it becomes too long, and the timing goes out of adjustment. Water pumps can fail on these engines around 50 - 80K miles, so check the coolant level regularly - every week at least, as the engine has no temperature gauge, only an overheat light, which can often be missed if it comes on. Your noise does not sound like water pump failure. Idle speed is low on these engines too - my car idles around 500 - 600 rpm when it is up to operating temperature, its presumably to save petrol and emissions at idle.

[vanadeo]

Okay thats good news, thank you so much for the information. How would I go about adjusting the valve clearances?. 🙂

[Stevie J]

I believe the rocker  cover has to be removed to give access to the camshafts, and feeler gauges used to check the valve clearances - ie the distance between the cam and its follower, whilst the cam is at its lowest point over the follower. The engine has to be rotated to check each set of 2 valves, first on the intake camshaft, and then on the exhaust camshaft. As long as they are between the specified tolerances, something like 0.15 - 0.25 mm Intake and 0.2 - 0.3 mm for exhaust, then they should be OK. Any larger clearances than those specified I believe the followers would need to be changed to larger sizes, so a fairly complex operation if all 16 valves need replacement followers, and this would likely be quite costly if a garage was to do it. This video shows the routine on a Toyota VVTi engine, its a bit drawn out, but he does seem to explain it in a roundabout way.