I keep my wife's 2000 RX 300 [ 48,000 miles ] in the garage at night. This morning there was a couple of drops of oil on the floor when I backed it out for her. After moving it outside I checked under the engine and found a bit of oil on the underside of the engine. Being a converted life-long GM owner I'm obsessive about this car. [ I'll never own another GM vehicle ] We purchased the car from the Lexus dealer about a year and a half ago [ w/ Certified Warranty ] and are extremely satisfied with the RX 300. Am I overly cautious about this or should I mention it to the dealer when I take it in for the oil/filter change next week? Is this a characteristic of this vehicle or just a fluke? Any input would be greatly appreciated, thanks.

 

might want to check to insure the oil drain plug (14MM) under the engine isn't leaking. This will leak if
it is tightened too tight, thus crushing the seal under it. It drips when crushed since the seal cracks!

If you'd like, try removing the engine cover by turning the Lexus seal counter-clockwise and removing
the three 5 MM studnuts at it's base closest to the radiator. Grip the nut sleeve as you remove each one,
insuring you don't drop one. The cover lifts right off to expose the valve cover with the oil cap. See if a
little over-spill around the oil filler cap is not the source of the problem . When replacing the cover, I
partically tighten the center "Lexus Plate" screw, then install the 5MM sleeve nuts all but the last couple
of turns. Jiggle the cover a bit to insure the cover is not binding, the tighten the three sleeve nuts. It's
common to tighten these too tight, cracking the plastic cover. I limit mine to 8 Inch pounds or about a
quarter of a turn past the screw seating or touching the plastic with no up/down play in the cover. The center Lexus nut is then "snugged" to the cover by feeling the detent as you turn it clock-wise, then one more turn. A little up/down play under the Lexus shield is fine...

 

You might wanna check to see if the front or rear bank valve cover gaskets are leaking. It's a common annoyance on 1MZ-FE and 3MZ-FE V6's. Alot of the leakage comes from improper break-in procedures when the car was brand new. Alot of people believe in break-in and some don't. With the MZ family of engines, it's crucial to follow that break in period to help the seals seat in properly.

 

Another thing is that most places that change the oil...i.e. Lexus & Toyota service depts that are lazy, will leave oil drippage from the oil filter after they spin it off. Alot of places forget to clean up that pooled up oil right off the motor mount and surrounding causing residual oil leakage.

 

Or the rear main seal

 

BY ALL MEANS mention it to the dealer at the next oil change. Since it's under warranty, let them find the reason or source for the leak. It may just be the drain plug, or sometthing minor, but if not, at least you will have brought it to their attention in case it is a major problem down the road. For a Lexus with this many miles, it should be a minor problem.

Good Luck

 

I want to say it's a case of lazy mechanics... but it might not be laziness.. I change the oil myself without even lifting the vehicle, but I would imagine that the sequence for changing oils at a shop for the RX would be to:

Lift the car.
Drain the oil.
Lower the car.
Remove the filter.
Replace the filer.
Fill the oil.

I don't believe the mechanic can get to the filter from underneath the car while it's draining without removing the splash shields, so they'd probably get to the filter from above. Once the car is down, they're not going to lift it up again just to clean the spillage from the filter removal.

If this leak occured right after an oil change, then check it again the next few days for any more leaking. Residual leaking should only last a day or two. If you're getting it day after day for like a week, then you have a leak from somewhere.

 

I have a couple hunks of 4X6 that I drive up on to. That extra 4 inches off the floor makes a big difference when sliding underneath for an oil change.

 

It's been 4 months since I had the car to the dealer for an oil/filter change. I noticed this oil leak about 2 weeks ago. I have an appointment this Thursday for another oil/filter change and will have them examine the situation then. She only drives the car about 500 miles a month but to keep up the warranty it has to be changed at least every 4 months. I've always performed routine maint. and repairs on our vehicles [ 30 year GM Tech ] but my wife wanted to have the dealer perform the routine maint. as long as it was covered by the Ceritied Warranty. I've always used Mobil 1 in my trucks and her previous car, but the dealer uses Valvoline so I guess I can live with that for another year and a half [ Then it will get Mobil 1 at home ] By then I'll have to get a service manual for the RX 300. [ The dealer wanted $ 100.00 for each of the 2 volumes ] I think I'll get a Highlander service manual and make it work [ Hey, I told you I was a Chevrolet mechanic, right! ] By the way, I get the 6-pack of Mobil 1 at Costco for about $ 23.50 !