There's no EGR on my Corolla. I'll have the base ignition timing checked. Any idea why it may be out of spec? The distributor and timing belt have never been touched. Is it possible there's something wrong with the ignition advance? How does it work in this model?
If that's the case, a top engine cleaner like GM used to sell would help. Have to figure a way to feed it through though, unless its a Throttle Body Fuel Injection system Tony
It is probably not engine deposits and the Corolla does not have a throttle body fuel injection system.
Any idea(s) as to what's different about them?
NO differences that have any impact of spark knock.
I have no clue what the differences are, just experience that tells me that some people experience ignition-related problems with aftermarket ignition parts. To be honest, I have not heard of pinging complaints that were caused by aftermarket plugs.
I agree with Phillip and qslm that incorrect base timing or a poorly or non-functioning EGR are the most likely causes of the OP's pinging.
Got the timing belt and tensioner changed. The water pump had a leak where it connects to the engine, so I replaced it too. After this, there was some obvious bearing noise due to overtight accesory belts. I returned to the shop and mentioned this, and they confirmed the belts were too tight and reduced the tension. The car is still noisier than before (clacking from the valve train area) and it seems to have less power. Could it be an over tight timing belt? Is it possible to check/adjust this without taking apart a lot of things?
Tnx!
Excessively tight accessory belts would not usually create a "bearing noise" immediately. They can *lead* to the destruction of bearings (even the front crank main bearing, if you're unlucky enough).
A clacking sound from the tbelt/valvetrain area would make me think loose tbelt, not tight. The belt could be hitting the plastic covers, or the slack could be causing a rattle between the cam drive slot and the distributor tang. Especially if the noise occured after tbelt replacement. Also, the new waterpump could be noisy, or the shop could have destroyed it's pulley during removal (it is a difficult pulley to remove if you don't know/care what you are doing).
Toyota MDT in MO
Does this model (4A-FE) have a timing belt tensioner spring? How is the timing belt tension set?
Yes.
You can turn the cam in the belt tightening direction while holding the crank to take the slack out of the belt, then assist the sprung pulley with light pressure, then tighten the pulley lock bolt down. Turn the engine over a few times and recheck belt deflection (this is where you use the service manual, experience, and common sense in equal parts). Redo the process if the belt is too tight or too loose.
Toyota MDT in MO
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