1996 Infiniti G20 it knocks

MOE522

MEMBER
1996 INFINITI G20
4 CYL
FWD
AUTOMATIC
162 MILES

When I first got it it did not knock as much as it do now at first the guy sid that it was probably a cv joimt that need replacing but we have notice that the sounds is coming no longer from the wheel and it is coming from the engine I was told it might br a lift that lift the cams up and down then I was told that I might need oil the oil is full a little dirty but filled what do you think is my problem

1 Reply

PEAR69

MECHANIC
1,482 POSTS

What is the octane rating of the gas that you put in the car. The octane rating it very important, here is why. Many people do not know what octane is or how it works-- you are about to learn--
Octane is an additive oil companys put is gasoline. Gasoline is very explosive, and when you compress it, it spontainiously explodes. Octane simply put, prevents this spontainious explosion. The higher the octane level, the less spontainious explosion. Why is this important?
When your piston, inside of your engine, is coming up to the top of the cylinder, it is compressing the gas/air mixture. If this mixture explodes as the piston is on the way up, before the spark plug ignites it, this causes what we describe as fuel ping or a knock. This also will cause severe damage to the engine in time. Run your tank down to almost empty and try a higher octane fuel.
If this dosen't do the trick let me know and we will take it from there.

BTW--Dirty oil means that the oil is doing its' job--that is good. What is not good is to go over 3000 or 5000 miles without changing it!