blueman2

When did the new design cover go into production? Can it be readily identified from the exterior or ar the changes interior only?

I have a 2001 RX300 showing signs of high oil consumption. Car is new to me, 125K, had oil changed a week ago and over the weekend, oil was at the low dot on the stick. I dropped a quart in to bring it back up and will check again next weekend. Did some research on oil consumption and found threads on the valve cover, PCV valve replacement, sludge and so on. Currently, car runs well, 19-20 around town and 21-22 on highway. Previous owner had a new throttle body installed fairly recently.

Thinking I should get a compression check, new PCV valve, perhaps some kind of top end cleaner depending on comp check results. Saw specs in one thread 218 psi normal, 160 psi min, max deviation of 15 psi between cylinders.

Thanks for any info or comments.

jolomo

My 2001 RX300 AWD did not have the new valve covers. It had the screw in type PCV valve. I acquired my RX at about 128,000 miles and I noticed disappearing oil immediately. Check the PCV inlet hose on the front valve cover to make sure it is not clogged. I didn't and lost my engine within 5,000 miles. An expensive lesson. My RX ran great with good mpg until it went, just like that. Hope you have better luck than me.

TreasurHNT

My wife's 99 RX300 is doing the same thing. It also throws out a nice billowing cloud of white smoke after sitting for 2 days. Also burns enough oil to set off the oil light after 800 miles - long trips especially.

PCV valve is a quick 5-10 minute fix. Did that on the weekend. Check the DIY section of the RX First Gen forum. Lexmex and the rest should be given Gold Medals for all the time and effort they have put into this thread. It has saved me many times.

Good luck. I'm starting the research on valve covers now because that's the next step for me.

If anyone else has suggestions or advice, let me know. Still have to replace the power antennae, fix the small gear/motor noise in the glovebox, and replace a rear side reflector / light if I can figure out what pieces to remove from the interior (some wierd plastic clip / bolt thing...) I know some of these are covered under the DIY.

carguy07

I thought all of the valve covers with the screw in PCV were the new design? Not true?

blueman2

I appreciate the comments thus far, will check these items out this weekend.

My RX does not show smoke and no apparent leaks but it must be burning oil cause the dipstick keeps showing lower.

I still don't have any info on when the new covers were introduced and whether they were fitted in production or only as a service item

The risk averse side of me says I should flip it while it is still running well and would be easy to sell, even if I lose a bit on it. Losing a grand is better than eating 4K in rebuild costs for either engine or trans.

jolomo

I wish I could give you some sound advice, but I don’t know if anyone can. It sounds like your problems were identical to mine. At 70 mph, I was losing 1.5 to 2 quarts of oil between gas fill-ups. At 50 mph, it would lose less than a quart. There was no smoke and I was averaging 18 to 19 mpg in town and 22 mpg on the highway. Everything seemed great except for the disappearing oil.

I replaced the plugs because they were the original ones. All the plugs looked great except that #2 had a slightly darker color than the rest but still looked OK. Apparently, that was a telltale sign, which I ignored, because #2 was the cylinder that failed.

I changed oil and used engine flush several times in the beginning and started using the high-end Pennzoil that cleans your engine.

We took the RX on a trip and during that trip, I read a post about checking the PCV inlet hose. While heading home, the CEL came on and the RX started running bad. We limped home.

At the last fuel, I topped of the fuel and oil, but forgot to replace the oil filler cap. I did not lose any oil the last 200 miles of our trip. I pulled the PCV inlet hose and it was clogged but my engine was already gone at that point. Checkout the post from Baetke at: https://www.clublexus.com/forums/rx-...0-miles-4.html

My advice if it is worth anything is:
1. Check the PCV input hose for any clogs.
2. Check your spark plugs and do a compression test while the plugs are out. Look carefully at #2 because I believe another RX owner had trouble with #2 also.
3. If the input hose was clogged and the plugs and compression are good, I would keep the RX. Use a good engine flush and oil. I believe there are ways a dealer or mechanic can de-slug an engine.

Hope this helps. Good Luck