I have a 2001 corolla NZE 121 1500 cc. It has poor mileage sometimes 10kpl. I have serviced it new plugs etc. Of concern is that the exhaust gases are usually very hot compared to other similar corollas. There is no check engine light. Could the very hot exhaust gases be a sign of something wrong in the engine? Thanks. maina

As advised by your mechanic, my advise is no different, in the gearbox there are what we term as teeth of different gears and synchronizers...being in such behaviour, your car needs a gearbox overhaul or replacement depending on which will cost you less

Many things can cause excessive fuel consumption. First, make sure that none of the brakes or transmission is dragging, or that the transmission is shifting properly. We had a car in the shop recently that had poor fuel mileage and one of the front calipers was dragging against the rotor. (also check the parking brake). Next, is everything up to tune? Good spark plugs, clean airfilter, good PVC, good Oxygen sensors, check for codes, etc. Check if there is a vacuum leak - (use a vacuum gauge). Lastly, if you have access to one, use a emission tester in the exhaust to see what the levels of hydrocarbons are. This will at least tell you if the engine is running clean. Sometimes poor fuel mileage might be a combination of things which all add up, like under-inflated tires, spark plugs fouled, parking brake slightly dragging and poor driving habits. I can always tell the customers who get poor fuel mileage by how often they need new brakes. Someone who lets the car coast and isn't on the brakes much usually gets much better mileage. Those who speed right up to a red light and then jam on the brakes at the last second usually have at least 20% worse mileage.

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I would suggest you run a compression check on this engine and also have the coolant recovery tank tested for the presence of combustion gases with a gas analyzer, any gases would indicate a leaking head gasket. Any engine cylinder that is lower than 5% of the highest reading cylinder in pounds per square inch has a problem like a scored cylinder or leaking intake or exhaust valve seat.

Count the wires comeing out of coil pack,,thats how many

check the spare part dealer or match the part physically, some have slighter different shapes and fittings

Keep doing regular oil changes , fuel and air filters if they havn't been done for a while. Timing belt every 100,000 km.
Everything else only as needed . Brakes , shocks , exhaust , etc.

SInce any noise from within the engine/gear box cannot be taken lightly, it is important that you will need a good look from a service shop. If you have been carrying out the scheduled service in accordance with Toyota timings, there will not be an issue. You could check out if the noise is external,otherwise get you car to the authorised Toyota centre for an estimate. This will be better than trying out/ stipping and then waiting for spares. I hope my advise is helpful. good day

oil/filter 10k. main service/filters.20k.plugs 40k timing belt60k.or annually as above.oil is 5/40 semi synthetic to 50k then10/40 to 100k,then 20/50 thereafter.following this regime you car will last years..........

use genuine Toyota oil 5w30 or Valvoline 5W30

That's called a "knock". You either have carbon on the cylinders which is fixed with a carbon depletion service, or you need to use a higher octane fuel.