nickd7

Hey guys, just bought an immaculate 2002 rx300 with 115000 miles on it thinking I had lucked out as its a Toyota motor and should last forever. As iv found out its a typical 3.0L burning 2 quarts in 7-800 miles (one week) not smoking, not leaking, lots of power. Iv found on here in a forum a guy with the same stats used 3 cans of mopar combustion chamber cleaner (supposed to be the best) to free the sticking rings that are creating the blowby, driving 500 miles between cans. Then swapping the valve covers for the new redesigned ones with better flowing pcv valve. Iv tried contacting him for more info on his procedure but he hasn't posted since 2013. Does anyone have experience with this topic that can help me out. My questions are as follows.

Is this combustion chamber cleaner an aerosol that I just spray through the throttle body with the vehicle running or something I have to pull plugs and dump directly into cylinders?

If aerosol, after I get the can in there do I shut it off quick and leave it sit? For how long?

Does anyone know for sure if both valve covers were redesigned or just the back one? (Id rather not change/buy both if only the back one is redesigned like iv heard.)

mmarshall

Welcome to CL.

Do you have accurate oil change and service records for your RX? The 3.0L V6 (the earlier ones, more so than the later ones) was notorious for sludge/gel and possible engine damage if the oil was not changed regularly. It had narrow oil-passages, and was designed to run hot for low emissions. That heat, though, did a number on non-synthetic oil, if you didn't keep it changed by the book. Most engines have some forgiveness-factor, if you got lazy or forgot your oil change.....that one didn't.

nickd7

I don't have a log book but it was owned by an older guy who I know was meticulous with everything about the vehicle. It was even undercoated and sprayed with oil before every winter. Not one spec of rust on the vehicle. Tbh he may have even ran synthetic in the thing it's whole life. Its just clearly a poorly designed motor.

salimshah

I would suggest that you add a catch-can to the lcv-air_intake path and confirm that the oil is making that path. If it is then further invest in the new valve cover. If you do a search you will find quite a bit of discussion on it. Some say bad design by Lexus some say it is a maintenance issue. My RX engine at 1/4 million miles does not burn oil and I am sure there are many more like me and may more who experience oil burn.

I have not used any oil additives and not a fan of such items. Check the instructions provided by the manufacturer and follow them.

Once agin .. verify before trying to fix.

Salim

nickd7

By this u mean make sure there is blowback pushing oil out of the breather tube that connects to the air intake side of the throttle body by pulling the hose off and running it into some sort of "catch can" to see if oil collects?

If lexus redesigned the valve cover that must be a good indication that they knew they had a poor design I would assume. There was also a large civil suit filed which Toyota paid out affecting 3.5 million vehicles with this sludge problem from what I understand and this motor was part of it.

salimshah

Yes.

Check out posts by DrCofee

Salim

nickd7

Thanks for your help I will make that my first step. This would obviously have to be done while driving not just idling?

One way or another though at this point I would assume I need to get these rings freed up as well to make a major difference in oil consumption?

Lexmus

I greatly doubt the Mopar cleaner affected the oil consumption by loosening the oil rings. Since the OP on the other thread changed the valve covers at the same time he did the treatment we will never know for sure, but many have posted here that their oil burning ceased when changing the rear valve cover, and I do not recall anyone being successful doing so with a spray into the intake.

On another car I was successful in unsticking the oil control rings using a seafoam soak in the cylinders, but that was a 4 cylinder and not a V6. A V6 has tilted cylinders that makes it difficult to soak the entire ring.

sylvia

I have no suggestion only to add something - for 350 miles trip i burned the whole 4 litre oil in rx300 2001. City drive ok, leaking just a drop per night, but as soon as go on a long trip like 4-5 hours drive burns the whole thing. I stop now every 2 hours, measure and add oil. Crazy!!!!

sktn77a

iTrader: (2)

Try replacing the PCV valve before going too crazy. Are you getting white/grey/blue smoke from the exhaust first thing in the morning when starting after an overnight cool-off?

salimshah

Sylvia:

Is this a recent observation or this has been happening for a while?

Also try to add a catch-can on the pcv path to the intake and see what you capture there.

Salim

nickd7

It does puff smoke after it sits and cools down from time to time when cat is cold. Usually after a faster drive. I'd say it's definately going up the pcv and into the intake. The higher the rpm the more oil it burns obviously. Judging by my symptoms I think I clearly need the updated rear valve cover.