trapreo

My 2000 Rx began using one quart of oil every 750 miles when I hit 130000 miles. It increased to one quart every 500 at 150000. It also developed a puff of smoke at startup that was getting worse. I decided after much research that I needed the redesigned rear valve cover. The only thing I couldn't figure out was how the car ran so well with the "poorly" designed valve cover for the first 130000. Before putting $800.00 into that repair I figured I would try to return the car to pre 130000 condition. With the rear valve cover removal being such a pita job, I was not going to remove it without the new one in hand even if I thought I had the mechanical ability to do it. So I left it alone. I did remove the front valve cover to check for sludge. It looked descent with very little sludge. I began by cleaning the baffles of both valve covers with Amsoil foam cleaner using the thin red straw in the PCV hole in the rear cover and in the little metal intake spout on the front valve cover. Then I put a half can of seafoam in the crankcase and drove for 100 miles. I then dropped the oil pan and cleaned it as well as squirt a little cleaner up the oil pump to clean the screen. Again some sludge but not much. I replaced the PCV valve with the SMP brand that has a smaller hole (big help but still smoking and consuming oil but less). Then I used the Amsoil foam to clean the intake by squirting it into the intake while my son Jake worked the throttle and then the throttle body through the hole in the throttle body the PCV hose connects to. I filled it up with Pennsoil High Mileage dino and drove for 500 miles putting half a can of seafoam in the crank case at 400 as well as filling the baffles with Amsoil foam again. I repeated everything except dropping the pan and removing the front cover again and drove 750 miles (Seafoam at 650). Did it again after 750 miles. Did it again after 1000 miles but this time I put in Castrol 0w40 to deal with the high heat of this motor and to prevent oil vapor that was getting sucked up the PCV valve and into combustion chamber causing the smoke in the morning and the oil consumption. An oil that has a low flashpoint and low HTHS causes lots of vapor(steam) that gets sucked up the PCV valve and out the tailpipe hence the black tailpipe. The oil vapor in the combustion chamber when you shut the car off then condensates during engine cooling and then ignites during startup hence the puff of smoke. Do I still need to explain the disappearing oil? With a clean PCV system, a clean motor, and an oil that holds up I am now at 1000 miles on the Castrol and the dipstick reads one millimeter higher than my first reading and I have yet to see any trace of smoke. My RX runs smooth and has more power and gets better gas mileage. I bought all the oil on sale with free filter(K&N HP2009) and with coupons I paid an average of 18 dollars per oil change. I spent less than one hundred dollars and have turned into somewhat of a shade tree mechanic. I have pride in the fact that I now take care of all my own maintenence. My new found confidence (and hobby) led me to replaced the spark plugs too. The ones in the back are easy if you disconnect the cruise control cable and have a few different extention sizes, skinny hands, and lots of patients. It took me one hour and eighteen minutes. Toyota garage wanted 600 bucks. If you have these problems please feel free to ask me any questions about this process.

trapreo

I do plan to use Castrol 0w30 this winter as it has great numbers too and matches the 30 weight operating temp Lexus recommends.

tllee

I did the same things but not repeat that many times as you did, I did use high pressure air to blow thru all PCV system and made sure air run thru smoothly. I thought that I solved the problem(oil mark was not lower even 1mm for over 1300 miles local drive + short highway drive) before I drove my car on a long highway trip(over 70MPH for at least a couple of hours).
Please try a long highway travel to see if it's fine. Bring a couple of bottles oil with you to prepare for the worst. I checked Toyota forum, some guys even took out the rear cover and clean it completely, but the problem still come back. I find that only one guy succeed by cleaning method, he took out the baffle plate(cut the rivets) and clean inside out and use self-tap screws to tight plate back. But I am not brave enough to do that(what if one crew drop down after a while?).

So I finally replaced my rear cover. The cost for parts is around $200(labor is high if you hire mechanic, I did it myself). For $100 difference, I spent it for peace in my mind. This is my whole story and hopefully could help you in some ways.

trapreo

I have driven about 700 highway miles at 70 to 75mph. I have thought about the fact it may be a revolving issue as the baffles may clog alot quicker in an older car but I am hopeful. Maybe I should keep my feet on the ground and declare victory when I have gone maybe 5000 miles without issue. What brand and weight oil do you run?

tllee

I think the this problem is caused by the "felt" like material inside baffle plate. It make the sucking power too much on the PCV system. I installed an oil-catch can once, I used transparent pipe, I can see oil sucked up and enter the can.
When our car aged, inside between the baffle plate and valve cover get more "stuff " to block the flow, it will increase the sucking power. So, if you remove the baffle plate and clean inside, you'll be fine for another 100000 miles at least. But considering the labor for this job, buy a new valve cover is another not-so-bad option. If the problem is the front valve cover, trust me, I'm not going to buy a new valve cover, I'll clean my cover every year,it only take 15 minutes to take it out.
The oil I used didn't make any difference, I used 5w-30, 0w-20,10w-30,etc.... After I changed valve cover, any oil(within spec. by manual)work fine w/o losing oil.

trapreo

I had almost no labor as I used the PCV hole without removing the cover to fill the baffle with Amsoil foam cleaner three times before my oil changes and Seafoam "foam" cleaner the last time before the final oil change. The foam fills the baffle and the gunk/sludge melts away. Then I ran seafoam in the crankcase for 100 miles before oil changes to wash away more blockage. I believe the extreme heat in the back bank cooks dino oil then when it hits other cooler parts of the motor it sludges. A high heat resistant synthetic doesn't do this. This is why some RX owners have never had these issues. They ran quality synthetic oil like BMW and Mercedes require because of their hot motors especially their turbos. I used dino up until this issue and now have made the switch. I have yet to find anyone using synthetic to have a blockage of any kind. Castrol 0w30 is a thick 30 with exceptional cleaning ability. Still......this is ALL theory until I get more miles of proof. I have no doubt the new rear cover will do the job for good and I give respect to tllee as he is further down the road with this issue than I am.

trapreo

1500 miles and still no oil loss. Will update at 3000

salimshah

Folks reported oil consumption at or above 70 MPH.

Please report that how many miles were driven with mph above 70 without giving the exact speed.

Salim

fastnoypi

before i replaced my rear valve cover on my '02....no oil loss during mostly city driving. There was significant oil loss during 30 min+ highway driving. It didnt matter regardless of multiple seafoam treatments both directly in the oil and through the valve cover breather hole. Oil consumption was tracked with a catch can before and after treatments just the time to fill the can was slightly affected.

trapreo

I drive 40 highway miles each day. I set the cruise control at 72. I have done 80mph to test it. I will say that the complete cleaning with FOAM that "fills the rear baffle" improved the oil consumption each time but not completely. The switch to a high HTHS rated oil with a high flash point was the nail in the coffin for the consumption. I used PP and PU before. Use anything but EURO oil in a BMW or turbo engine and you will have loss even in a brand new engine. This engine runs hot new and hotter as it gets old. PP and PU will burn up in my coworkers fiat turbo. With Castrol european 0w30 he gets no loss over 5000 miles. I did remove the front and clean it but used the foam that swells in the baffle in the rear. Oil was clear for 1100 and now is starting to turn gold. Again, time will tell if this is an acceptable fix. Not enough data to be absolutely sure but it does look good to this point.

trapreo

Catch can retreives vapor and oil. You see the loss. High HTHS oil with high flash point equals less or no oil vapor. You do need a clean engine or oil will break down too quick. Read my reply to Salim's last post.

fastnoypi

Correct, that is how a catch can works....regardless of the type of oil you use, the intake manifold provides that vacuum to pull vapor from the rear valve cover baffle and pcv. This 1mz-fe is not a high revving motor, even using a high HTHS oil will have oil vapor, the pcv system is mandated as part of the design to introduce the oil vapor into the intake to get burned in the combustion process for emissions reasons.
Pull the rear valve cover off and you can see the poor design of where the cam whips the oil right onto 3 breather holes of the rear valve cover baffle. The newer design found in the rx330 sets the breather off to the side away from the cam lobes to minimize clogging and oil consumption through the pcv.

Its simply the 2 designs of the rear valve cover found in these 1st gen RX's that clog up over time. More so in vehicles that experience short driving distances where the oil does not have enough time to warm up and expel condensation.

If your seafoam foam solution worked for you, that is great. IMO its not a one solution fits all. Due to the high amount of short distant type of driving in mine, all 3 breathers were gunked while the rest of the head was extremely clean due to M1 synthetic oil. Barely any air would pass through the breathers when i removed the rear cover and put shop air up to it. After 2 days spraying oven cleaner into it , reconditioned it like new if i decide to ever use it as a spare.

On a side topic, you should consider getting a new MAF and/or pair of front o2 sensors if you think your car is running hotter as it ages. If it truly is running hot, then it is most likely running lean if you dont have a coolant system/fan problem existing.

You can't really compare your friend's oil consumption experiences to that of your RX. In a turbo situation, lots of the loss is usually due to blowby under boost and/or stuck pcv, but you right that German Castrol is an excellent oil that is stable against sheering down quickly compared to other oils.

salimshah

And if the new redesigned cover worked for you (and others), that is great.


And for those who have had the original designed valve cover (with or without design flaw) and do not have a problem, that is great too


Salim