2001 Lexus Rx300 - Need Advice On Oil Weights

[sheffield_rogue_jr]

Hi fellow Lexus enthusiasts. You can skip down to the bold text if you do not want to read the background of my post :whistles:

-------------------------------------------------------------------------

I recently drove my 2001 RX300, which I had acquired last October, on a road trip between Chicago, IL and Toronto, Canada between July 16 and July 25. The only maintenance-related issue that had to be taken care of, an oil change, was completed. I took the car to my local mechanic a couple of weeks before we left and I had him test-drive for a few blocks. He stated, based on his observations, that the car ran well and could be trusted to make it to Toronto and back in one piece.

With about 137,000 miles, this car ran like a top with no loss of power, no transmission jerking, and got roughly 19-20 mpg the entire way with the a/c running at full blast. Driving around Toronto, my mpg went down, but the performance stayed just as well as it had been along the highway. However, a few days after we got to Toronto safely, I was exiting the highway (the famous Highway of Heroes) and, coming to a stop at the end of the downward-sloped ramp, the Oil Pressure light came on for roughly one second and then went out. Initially, I attributed the light to the steepness of the ramp, but I was disconcerted enough to go back out to the car the next day in the morning with a paper towel and pull the dipstick.

I popped the hood, drew the dipstick, held it level to my eye, and my jaw nearly dropped. Yep. The dipstick was as dry as the Grand Canyon, with not even a single drop on it

That same day, I picked up a jug of Mobil 5W-30 synthetic at a local auto store and added right up to the top mark on the dipstick (thank god I had a funnel with me). I dreaded that I would have to repeat the process when I got back to Chicago; when I did so (the dipstick was dry again when we got back), I got the same weight, only as mineral, and only added enough to bring the oil level near halfway between the two marks. Again, there were zero issues related to performance along the way back, and it still amazes me that this is possible. Unfortunately, it never occurred to me to check the oil level at any stopping point along the way in either direction, so I have no clue what the burn rate is .

Here in Chicago, the car often sits for days at a time in the same spot on the street if it's not winter, as I prefer to ride my bike for the fuel economy B). I would have noticed fresh oil spots under my car if there was a leak, and (with the exception of a FEW start ups) there is no smoke coming from the tailpipe either in city or on the highway. To be specific, there is a small amount of bluish smoke upon startup, but ONLY once in a while - it does not happen each and every time the car is started.

Yesterday, I went back to the same mechanic to tell him about this little problem. He replied that, as there is no leakage, the engine is burning up oil in small quantity, which was not obvious until my trip. I was advised by him to switch to a heavier oil at the next change to reduce the likelihood of it getting burnt.

-------------------------------------------------------------------------

A couple of questions to you, for those of you currently running oils heavier than 5W-30 in the RX300: how heavy have you gone without appreciable decline in performance? How heavy is it possible to run and still be able to operate the vehicle in the winter? (keeping in mind that Chicago winters, although not as cold as the Arctic, are certainly powerful) And lastly, is warm-up time affected badly by a heavier oil (both in summer and winter)?

Any pointers that I can get are highly appreciated. ^_^

[1990LS400]

I don't regard using 4 or 5 quarts of oil in 500 to 600 miles as a "little problem". Something is very wrong and a mechanic should be able to quickly figure out where all that oil is going.

I doubt that using heavy oil is going to help if your engine is using oil at such a high rate.. I suppose you could try "straight weight" 40W or 50W if you can find it if you don't want to spend money on identifying and fixing the problem but I doubt if your engine would start in those warm Chicago winters.

[lenore]

Actually you may have a sludge issue, but start with a new PCV valve, and then you may want to try some AUTO RX engine cleaner. Not sure where to get it, but It may help your engine. I would be very careful, as your engine should not be throwing that much oil...Cleaning your engine at this point is very important. You may want your mechanic to pull front valve cover and see if you have a major sludge issue..good luck.