Ok rx 300 2000 model has loud knocking noise codes p1150 pending and p0125 .check oil level ok oil change every 3000 k miles always been using 93 octane gas so should i buy knock sensor? Pls. Help.

 

The RX300 should run fine on regular (87) octane. In fact, ours ran better than on mid grade or premium. Is the knocking you're describing ignition knock or something worse, like rods? Do you use Lexus for service or an independent? The reason I ask is the front splash panel makes it hard to get to the oil filter. A lot of independent service people didn't know the tricks to get to it easy and just changed the oil w/o changing the filter too. There is history of some of those engine family building a lot of sludge in the crank case because the filter wasn't changed. Usually the owner was trying to save a few maintenance dollars and the independent maintenance guy was trying to save a few minutes rather than do it right. Hence the sludge

 

This is the first time I've heard that oil sludge is caused by lack of oil filter changes. Can you tell us more about this? Where is this "history" documented? Thanks for your help.

 

When we bought our '03 RX300 back in 2003 I first did a Google search of history. It mentioned it then. Was not a fault of the car or engine, but warned of cheap fast oil change places that didn't take the time to remove the lower splash panel to get to the oil filter. If you look down inside your hood where the filter is, you can see that the splash panel under the car blocks access and needs to be removed to reach the filter easily. The article said if you use a non-Lexus place you could reach down from the top with a screw drive or other instrument and make a visible scratch on the filter before you had the oil and filter service performed. Then you could tell if they changed the filter or not.

 

Thanks. I have a 99 which doesn't have this problem - the filter comes out from the top without too much trouble. The sludge recall included 99's so our engines are prone to sludging even with regular oil/oil filter changes. I guess infrequent oil filter changes just make things that much worse.

 

I've seen mechanics take the oil filter out from the top, but I think small hands help. I think I would have a hard time taking it out from the top.

From what I've read, my opinion is that sludging doesn't happen if you have been doing frequent oil changes with quality oil (i.e., maybe every 3-4,000 miles with a 1st-quality quaker state, penzoil, or another name brand oil). I wonder about the quality of oil that even some dealers are using.

 

Well this thread is morphing into oil, filter and engine gel discussion. I have been replacing the filter from the top, but I wait for exhaust to cool down. That may be the issue with quickey oil change places.

Back to the this plaka's issue:
The sensors are being reported as bad. You can confirm by checking the ohmage or voltage at the sensor, and for that you will need good sensor spec'ed values. If you dont have them, then run two tankful of premium gas and if the codes do not go away, try changing the sensor.

Salim
5,4,3,2

 

Huh??

 

That would be "Huh X2" ??