Is petrol to blame?

[ghaxanfer]

Hi:


I have a 2007 Altis manual. I got maintenance from dealer in karachi. I feel that pickup is not as good as before and it is vibrating and knocking on low speeds. The advisor said that they get this complaint in the new cars as well and this is because of poor quality of the petrol sold locally.


They tell me that the tuning is computerised and raise/rpm/tuning cannot be adjusted manually by adjusting any wire or screw. They say I should change brand of petrol and use high octane.


I would appreciate if anyone can share their experience in this regard. Can the tuning be adjusted according to individual speed needs?? or is it really due to petrol quality?

[ifrahim]

use octaine booster

[bango]

Check your brakes.

If not disengaged fully, the car seems to feel 'heavy', like ''ghut ghut ke chal rahee hai''

[argtr65]

Yes, it could be due to usage of contaminated petrol.Some times usage of substandard spark plug could be the source of this problem

[irfansiddique]

i personally feel that these locally manufactured cars only get hit when you put very very low grade fuel, which i feel is not available in karachi pumps. yes low quality fuel is there but not very low, my friend was having some sort of similar problem in his City 07, mechanic checked and identified that the points connected with spark plugs were either loose or not getting short he opened them, clean them with fuel and re - fit and the problem disappeared, so i would advice you to get it checked it might be the problem, also get your spark plugs checked, and fuel injectors too.

[309]

yeah check the brakes first and also by how much psi do u get ur tyres inflated? tyres pressure also plays a role in giving the car a heavy feel coz if low pressure the tyres wud be really draging on the road. and yeah mixing 10 ltrs of hi octane with super supreme will also prove good for the enigne plus u will feel a change in pickup too. we do the same in our cars. but do not use more than that as the manufacturers recommend 88octane fuel for civics and corollas which is super supreme so adding more than that won't do the engine anygood.

[ghaxanfer]

thanks for the responses:


I discussed about spark plugs, the advisor told me they maintain 100 micron gap and that spark plugs were inspected and are ok (just replaced 5000km ago). They will not adjust anyother gap for sparkplugs. Sparkplugs are toyota genuine part ones.


Tyre pressure is 28psi front/30psi rear. I check it regularly.


Brakes were just inspected, the pads were checked and ok. I am depending on the work done by the dealership and advisor's feedback. brake pads are toyota genuine part ones.


Is it possible that the brake doesnt fully disengage? the dealer told me that it is ABS brake and they cannot adjust the brake manually at all.


Now every problem I take to them, they tell me everything is electronic and they cannot adjust manually(kuch chare nahi saktay). In other words they tell me to adjust my driving habits to the car settings.


Now I will add some hi-octane to check any difference.

[HumanGenius]

Thats odd :s
Good luck though (Y)

[argtr65]

Also get cam sensor checked,some times it's mounting bolts looses due to vibration and causing for advancement in spark time which may be the cause of knocking.


Some times, if O2 sensor fails to perform its duty then it will not maintain the air fuel ratio properly,result in engine knocking.