vrx300

hey guys new to this forum! i recently bought a pre owned 2001 rx300 and a month later my car starting to knock or ping or atleast it sounds like that

anyways i switched the fuel grade from 87 to 89, in the hopes that the sound will stop, its been 2 days

oh and for more details, i mixed 89 and 87(still had alot of 87 left),

any idea on when the sounds will stop now??

please help!

vrx300

anyone????

carguy07

if you think really think the octane is too low, then put some decent gas in it and see what happens.

vrx300

i switched from 87 to 89(while i still had more than half a tank of 87 left) and its been 2 days since i filled it up

is there any way to find out if this is an octane problem or some other kind of problem(collapsed lifter, egr valve issue)?

carguy07

Not really without putting decent gas in it. 1/2 tank of 87 + 1/2 tank of 89 = full tank of low octane crap. Most of us do not have any issues running low octane gas. The knock sensors do a pretty good job avoiding detonation. The lifters are solid, so don't worry about that. Assuming the CEL works and is not on?

vrx300

Yup CEL is working and unfortunately on

carguy07

Well, start with that. See what codes you are getting and report back. Nothing else matters if the cel is on. You may want to reset and drive until it comes back on, then read the first code that pops up.

salimshah

Welcome to CL.

We try to answer all posted questions, but do not expect a quick response as the members are not monitoring the posts 24/7.

Also before any one else can postulate about your vehicle, your engine control unit is in command and any indicators about malfunction should be investigated. Granted the ECU only monitors fuel/ignition/emission (does not cover all possible things that can go wrong), fortunately in your case the problem is related to ignition.

Carguy07 is one of our most respected/knowledgeable member. You are in good hands.

Salim

fastnoypi

reset your ecu by removing your positive battery terminal cable. It should reset any learned knock correction.
Also consider a top end cleaning and pcv change, carbon deposits from pcv oil blowby can contribute to knock, as well as oil mist degrades octane levels in the air/fuel mixture that can also cause knock.

Bobster999

Its highly unlikely to be fuel octane related. I would suggest having a real mechanic look at it. Its virtually impossible for anyone on the net to diagnose your problem from our home.

AnthonyMtz

Cheapest route is to get a bottle of a good octane boost the nos brand one seems to work really good, you might want to feed the Rx a bottle of red line too! Good luck