Reengineered rear valve cover??
08-18-22, 08:28 PM
#211
Moderator
Who ever installed 3rd gen valve cover and has 100K miles with it
Is there any one who has 2x the miles since they installed the 3rd gen valve cover report on loss/no-loss through the valve cover? If I remember is it right a member had issue with 2nd gen used valve cover [Issue meaning still losing oil].
Where x is the milage when you replaced the valve cover.
Salim
PS: People who reported oil loss encounters it well past warranty period. No one replaced their valve cover with new old version [understandable]. I am concerned that with 100k miles 3rd gen valve cover, does the problem come back?
Where x is the milage when you replaced the valve cover.
Salim
PS: People who reported oil loss encounters it well past warranty period. No one replaced their valve cover with new old version [understandable]. I am concerned that with 100k miles 3rd gen valve cover, does the problem come back?
Last edited by salimshah; 08-18-22 at 08:33 PM. Reason: PS
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MattRX (08-20-22)
11-07-22, 12:46 PM
#212
Is the fix working on 11-7-22
03-22-23, 04:54 AM
#213
Typical for me, I accidentally lost my first post before it was finished so I'll try again. I bought a 2001 Lexus RX300 w/ 80,600 miles. The color is burnished gold. CARFAX showed that it was a one owner car from Long Island and was obviosly a short-hop errand car as it normally posted about 700 miles per month. Everything worked, though it was a bit scuzzy from tree sap and pollen. I washed it with Greased Lightning and a sponge and plenty of water. Then rubbed it down twice with polishing compound and it now looks like new. (also used RainX wax twice)
The point of what will come up on this post is that the Lexus Forum presents a lot of really good information and fixes that aren't always talked about much elsewhere. So, Thanks, Lexus Forum! Almost all of my solutions came through the forum postings.
1. Replaced plugs w/new Iridium performance plugs (supposedly a more complete burn). Also replaced the oil with Mobil 1 5W30 Synthetic for an upcoming cleaning. ($135 w/labor). Also had all the fluids replaced (about $200 w/labor). As a final help, I added XADO friction reducers to everything except the engine) I ordered from Amazon and the cost w/labor was about $75. (transaxle, rear axle, power steering, and auto trans.). Supposed to be good for 60,000 miles. The running gear is now dead quiet; really nice.
2. Read nearly 641 posts about the RX for education and new information; took a few months.
3. The RX was already on its second exhaust and it was getting weak. I Installed a Walker Quiet-Flow Stainless Steel exhaust system for $685 plus $115 labor. The Walker is a three piece system, with a CAT Conv., (#16121) muffler (#53406) and extension pipe, and the resonator assembly (#56096) with a short pipe and a built in tip. I ordered this at Advance Auto Parts and it took about 4 days to get there. (Always double check all parts and part numbers). It's quiet but has a subdued deep sound to it.
4. The steel rims were rusting at the spokes and the Michelin tires were not wearing even. I replaced the rims with Voxx alumn. wheels and Cooper CS4 Touring M+S tires. I ordered both from Discount Tires Direct. They were delivered to my door for $900. (80.000 mile tires)
5. Took the RX to a good alignment shop and they balanced all four tires and did a front alignment (rear was ok). (Cost was $97)
6. To this point, the car was getting 18 mpg no matter how you drove it or what grade of gas you used! This indicated one or more problems. I added 4 oz of Seafoam to the gas tank and asked how much it would cost for a new fuel filter. Surprise! The 2001 RX does not have a fuel filter under the seat. It uses a fuel screen set up that is mounted in the fuel tank. I drove the car for about ten milles and the mileage improved a little. The engine sputtered a time or two then began to smooth out, so I added four more oz of Seafoam to the tank. By the time tank was near empty the mileage was hovering at 19 mpg and I had a better throttle response also.
7. It worked so well that I added the remaining half-bottle to the oil as recommended by a couple of the Forum members. This to see if my dip-stick would turn from clean to dark and how miles it took to get there. At 10 miles, no change. 25 miles it was a little darker. At 100 miles it was a dark amber so I took it in for an oil change.
8. The really big fix was to order the upgraded rear valve cover, new pcv, and hoses. (I was using 4-5 qts every oil change.) I took my Forum info into my Toyota dealer and he went to the updated / revised numbers in the upgraded parts screen and found the parts almost immediately. (The parts came to $293 and the labor was an additional $150) The numbers were good. Here they are, direct off of the Toyota Invoice (these are special order items.) 11201-0A060 rear valve cover assby; 11213-0A010 valve cover cylinder gasket; 12204-20040 PCV valve; 12261-20091 ventilation hose. The pcv valve is a precision all metal unit made to fit this valve cover. The parts man also said it had a higher flow rate than the plastic one. The baffle on the valve cover is smaller and at different angles. The baffle chambers on the cover seem longer and more of a precision casting. I'd recommend ordering three or four valve cover bolts as they have a tendency to shear off on some of these V-6s. I now have 2,000 miles on the new setup with "cruises" of 60, 70, and 80 mph with no loss or use of oil whatsoever! This is a great fix! Also added XADO to oil to further reduce friction. The V6 is now super quiet and their was no sludge at all when we checked the RX before the new valve cover went on!
Coming back from a doctor's appt I got an avg of 23.1 over the 45 mile trip. Around town, I'm getting 19-22 depending on the traffic. These are 'liveable' numbers!
So what's left. The 90,000 service. That will cost around $800 with my independent mechanic. He uses the hi-grade kit and includes water pump and thermostat and replacing the antifreeze. I will also drain the Mobil1 Turbo Diesel 5W40 synth. oil (no clolor change after the 2,000 miles) and replace with AMSOIL 5W30 Signature series and try going a year between changes. I think it will make it. But I'll try to locate some petroleum 'litmus' paper and see if the acids remain low. Should be interesting.
I really believe that using a good synthetic oil is the best insurance you can get to prevent sludge and extend engine life. I use them in every piece of power I own.
That's what I've done to this point, thanks to the Lexus Forum. Everything I've tried has worked or has done no harm. But I can only verify what worked for me. Do your own research and let that and your pocket book be your guide! When the 90,000 mile service is done I will have a little over $16,000 invested in the car. It pretty much acts, looks, and handles like new and has the most efficient A/C I've ever seen in a car. It uses .3 mpg at 65 mph. Terrific! I now have a really great luxury SUV for a reasonable price. Let's hope it holds up! Thanks for letting me pass on what has worked to far, thanks to the Forum members!
The point of what will come up on this post is that the Lexus Forum presents a lot of really good information and fixes that aren't always talked about much elsewhere. So, Thanks, Lexus Forum! Almost all of my solutions came through the forum postings.
1. Replaced plugs w/new Iridium performance plugs (supposedly a more complete burn). Also replaced the oil with Mobil 1 5W30 Synthetic for an upcoming cleaning. ($135 w/labor). Also had all the fluids replaced (about $200 w/labor). As a final help, I added XADO friction reducers to everything except the engine) I ordered from Amazon and the cost w/labor was about $75. (transaxle, rear axle, power steering, and auto trans.). Supposed to be good for 60,000 miles. The running gear is now dead quiet; really nice.
2. Read nearly 641 posts about the RX for education and new information; took a few months.
3. The RX was already on its second exhaust and it was getting weak. I Installed a Walker Quiet-Flow Stainless Steel exhaust system for $685 plus $115 labor. The Walker is a three piece system, with a CAT Conv., (#16121) muffler (#53406) and extension pipe, and the resonator assembly (#56096) with a short pipe and a built in tip. I ordered this at Advance Auto Parts and it took about 4 days to get there. (Always double check all parts and part numbers). It's quiet but has a subdued deep sound to it.
4. The steel rims were rusting at the spokes and the Michelin tires were not wearing even. I replaced the rims with Voxx alumn. wheels and Cooper CS4 Touring M+S tires. I ordered both from Discount Tires Direct. They were delivered to my door for $900. (80.000 mile tires)
5. Took the RX to a good alignment shop and they balanced all four tires and did a front alignment (rear was ok). (Cost was $97)
6. To this point, the car was getting 18 mpg no matter how you drove it or what grade of gas you used! This indicated one or more problems. I added 4 oz of Seafoam to the gas tank and asked how much it would cost for a new fuel filter. Surprise! The 2001 RX does not have a fuel filter under the seat. It uses a fuel screen set up that is mounted in the fuel tank. I drove the car for about ten milles and the mileage improved a little. The engine sputtered a time or two then began to smooth out, so I added four more oz of Seafoam to the tank. By the time tank was near empty the mileage was hovering at 19 mpg and I had a better throttle response also.
7. It worked so well that I added the remaining half-bottle to the oil as recommended by a couple of the Forum members. This to see if my dip-stick would turn from clean to dark and how miles it took to get there. At 10 miles, no change. 25 miles it was a little darker. At 100 miles it was a dark amber so I took it in for an oil change.
8. The really big fix was to order the upgraded rear valve cover, new pcv, and hoses. (I was using 4-5 qts every oil change.) I took my Forum info into my Toyota dealer and he went to the updated / revised numbers in the upgraded parts screen and found the parts almost immediately. (The parts came to $293 and the labor was an additional $150) The numbers were good. Here they are, direct off of the Toyota Invoice (these are special order items.) 11201-0A060 rear valve cover assby; 11213-0A010 valve cover cylinder gasket; 12204-20040 PCV valve; 12261-20091 ventilation hose. The pcv valve is a precision all metal unit made to fit this valve cover. The parts man also said it had a higher flow rate than the plastic one. The baffle on the valve cover is smaller and at different angles. The baffle chambers on the cover seem longer and more of a precision casting. I'd recommend ordering three or four valve cover bolts as they have a tendency to shear off on some of these V-6s. I now have 2,000 miles on the new setup with "cruises" of 60, 70, and 80 mph with no loss or use of oil whatsoever! This is a great fix! Also added XADO to oil to further reduce friction. The V6 is now super quiet and their was no sludge at all when we checked the RX before the new valve cover went on!
Coming back from a doctor's appt I got an avg of 23.1 over the 45 mile trip. Around town, I'm getting 19-22 depending on the traffic. These are 'liveable' numbers!
So what's left. The 90,000 service. That will cost around $800 with my independent mechanic. He uses the hi-grade kit and includes water pump and thermostat and replacing the antifreeze. I will also drain the Mobil1 Turbo Diesel 5W40 synth. oil (no clolor change after the 2,000 miles) and replace with AMSOIL 5W30 Signature series and try going a year between changes. I think it will make it. But I'll try to locate some petroleum 'litmus' paper and see if the acids remain low. Should be interesting.
I really believe that using a good synthetic oil is the best insurance you can get to prevent sludge and extend engine life. I use them in every piece of power I own.
That's what I've done to this point, thanks to the Lexus Forum. Everything I've tried has worked or has done no harm. But I can only verify what worked for me. Do your own research and let that and your pocket book be your guide! When the 90,000 mile service is done I will have a little over $16,000 invested in the car. It pretty much acts, looks, and handles like new and has the most efficient A/C I've ever seen in a car. It uses .3 mpg at 65 mph. Terrific! I now have a really great luxury SUV for a reasonable price. Let's hope it holds up! Thanks for letting me pass on what has worked to far, thanks to the Forum members!
03-22-23, 07:10 AM
#214
My 2000 RX has ~130K miles and was using 1 Qt of oil in ~300 miles on highway. It also started to smoke at start-up after a 20 mile or so trip. In Nov of 2022 I reversed the PCV valve flow as per this thread mod. After reversal the car made ~1,100 miles with no visible change in the oil level on dipstick. No smoke on the start-up. However the car developed a significant oil leak (It had a minor leak before). Definetely from the front valve cover gasket and perhaps from other(s). I suspect that the crankcase pressure may be high, therefore PCV valve does not releive it as it should. I keep monitoring and will report in another few months or if someting happens to discontinue this watch. The car runs great othervise.
03-22-23, 08:23 AM
#215
Moderator
I agree that it not a good idea to block the valve.
If you are interested to try other things, devise a catch can in the path. You can always dump the collected oil back into the block.
Salim
If you are interested to try other things, devise a catch can in the path. You can always dump the collected oil back into the block.
Salim
03-22-23, 08:37 AM
#216
Thanks Salim for reading my post and commenting. My understanding was that the PCV valve would work if placed on the front cover and piped back to the original hose. Your comment makes me wonder if that is not the case. For example, there is a check valve inside the fron cover that prevents the flow out of the front cover and into the moved PCV valve...
03-22-23, 08:56 AM
#217
Moderator
I assume front/back is the literal front and back [radiator side and firewall side].
The v6 is installed with a twist, making the radiator side V arm slightly higher than the V arm on the firewall side. For what ever reason Lexus/Toyota engineers have the PCV on the lower V arm and the breather on the higher arm.
There are so many theories about the cover being bad or drain tubes being too thin or the driven speed (rpm higher than expected) .. as the vehicle design speed was 65 Mph and now with that speed you will get run over from behind,
In any case the engine oil is getting past the PCV and simplest way is to recover and reuse. Catch can, although modifies the emission plumbing, which is considered tampering, but at least it does not try to change the intent or emission control. In any case gen1 is now getting into antique [for emission standards atleast] so the legality may be a moot point.
Salim
The v6 is installed with a twist, making the radiator side V arm slightly higher than the V arm on the firewall side. For what ever reason Lexus/Toyota engineers have the PCV on the lower V arm and the breather on the higher arm.
There are so many theories about the cover being bad or drain tubes being too thin or the driven speed (rpm higher than expected) .. as the vehicle design speed was 65 Mph and now with that speed you will get run over from behind,
In any case the engine oil is getting past the PCV and simplest way is to recover and reuse. Catch can, although modifies the emission plumbing, which is considered tampering, but at least it does not try to change the intent or emission control. In any case gen1 is now getting into antique [for emission standards atleast] so the legality may be a moot point.
Salim
03-22-23, 11:00 AM
#218
Thank you again Salim for clarifying. We may never know if the reversal of the PCV flow blocks the flow and therefore increases the pressure inside. Before doing the reversal I checked what others reported. Most reports end at a few hundred miles. I found one report past reversal after ~8K miles with no other engine issues. If my RX lasts a year or two, my mission is ackomlished…after 22+ years and 133K miles one cannot complain.
03-22-23, 11:13 AM
#219
Lexus Fanatic
Reversing the PCV valve is crazy you're going to over time damage every seal in the engine due to excessive pressure.
03-22-23, 11:43 AM
#220
I did what is described in this thread LeX2K.
Old 08-18-22, 04:01 PM
#209
geraldd62
Perhaps my wording was a bit not clear. I moved the PCV valve from the rear valve cover to the front valve cover and the breather hose from front to rear. If there are no other valves preventing the reverse flow, this should be OK.
Old 08-18-22, 04:01 PM
#209
geraldd62
Perhaps my wording was a bit not clear. I moved the PCV valve from the rear valve cover to the front valve cover and the breather hose from front to rear. If there are no other valves preventing the reverse flow, this should be OK.
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LeX2K (03-22-23)
03-22-23, 11:56 AM
#221
Moderator
I think the word "reversal" in a PVC setting is throwing us off. The valve is a one way [check valve]. Swapping banks is what it seems was implemented.
If it was indeed a reversal [blocking vapor venting] would for sure increase air/vapor-mix pressure in the bank and forcing the oil out of seals/cover.
If it was swapping, I have no idea what the ramifications would be ... breather hole size, location where the rising oil may end up/build-up etc.
Salim
If it was indeed a reversal [blocking vapor venting] would for sure increase air/vapor-mix pressure in the bank and forcing the oil out of seals/cover.
If it was swapping, I have no idea what the ramifications would be ... breather hole size, location where the rising oil may end up/build-up etc.
Salim
03-22-23, 12:22 PM
#222
I 100% agree. A much better description is swapping. I recalled that a reversal was said in the past and used it. We will find out the ramifications, in time. It is a research project for me after 22 years of almost a trouble-free ride. The car is worth ~ $500 on a trade-in.
08-15-23, 03:04 AM
#223
5th Gear
Join Date: Aug 2023
Location: Italy
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Something I do not understand
Good morning everybody from Italy.
My Rx300 is a 2002 and has160k miles on her. She was mine from new and always correctly maintained; about 13 years ago I relocated her in our second house so she's driven much less than it was used to.
Always used synthetic oil, from the beginning.
I have now the same issue discussed here of excessive oil and fuel consumption associated with a rattling noise when accelerating, mostly from low speed. I take that's knocking since ECU is not able to accommodate given the excessive amount of fuel and oil, as explained in other threads.
I already replaced about 5 years ago both knocking sensors because of the known issue which puts the engine in protect mode not allowing overdrive to catch up, so I'm sure it's not that the culprit for knocking.
So after reading a lot of posts and threads here, I'm going to collect the suggested upgraded parts to get rid of the issue once and for all; hopefully it'll get rid also of knocking, although carbon residuals may have grown in combustion chambers, but that can be fixed with enough amount of Pea fuel additive.
So I'm going to do the job in a shop and I'll attach extraordinary maintenance such as spark plugs, timing belt, etc. Any other suggestion of things to do, given the opportunity, are very well accepted.
Now the real question, if someone has an answer, since I couldn't figure out any that makes sense: why in the hell it worked fine for so many thousands of miles and then it's necessary to replace the valve cover?
I mean, if it was a design fault, why it worked fine for about 20 years and 150k miles? It should have failed from the beginning... I read several attempts to replace just the valve and the hose but with no success, so that alone doesn't work. But this does not makes sense to me. If it was poor design for the valve it should have been the same, failure after a given time but replacing the valve should have fixed the problem and instead it didn't for the people who gave it a try.
So now I'm a bit puzzled although firmly convinced to apply the correction.
I'm not an engineer, just a doctor with a passion for cars and mechanics, but I don't get well along with things I do not understand and this is one of them 🤦.
If anyone can explain me all the things I don't grasp in this mess I'll be very grateful 😁
And a huge thank you to all of the experienced guys who contribute here and help us to avoid shops to throw useless new and expensive parts in our cars...
Warm regards from Italy
Salvo
My Rx300 is a 2002 and has160k miles on her. She was mine from new and always correctly maintained; about 13 years ago I relocated her in our second house so she's driven much less than it was used to.
Always used synthetic oil, from the beginning.
I have now the same issue discussed here of excessive oil and fuel consumption associated with a rattling noise when accelerating, mostly from low speed. I take that's knocking since ECU is not able to accommodate given the excessive amount of fuel and oil, as explained in other threads.
I already replaced about 5 years ago both knocking sensors because of the known issue which puts the engine in protect mode not allowing overdrive to catch up, so I'm sure it's not that the culprit for knocking.
So after reading a lot of posts and threads here, I'm going to collect the suggested upgraded parts to get rid of the issue once and for all; hopefully it'll get rid also of knocking, although carbon residuals may have grown in combustion chambers, but that can be fixed with enough amount of Pea fuel additive.
So I'm going to do the job in a shop and I'll attach extraordinary maintenance such as spark plugs, timing belt, etc. Any other suggestion of things to do, given the opportunity, are very well accepted.
Now the real question, if someone has an answer, since I couldn't figure out any that makes sense: why in the hell it worked fine for so many thousands of miles and then it's necessary to replace the valve cover?
I mean, if it was a design fault, why it worked fine for about 20 years and 150k miles? It should have failed from the beginning... I read several attempts to replace just the valve and the hose but with no success, so that alone doesn't work. But this does not makes sense to me. If it was poor design for the valve it should have been the same, failure after a given time but replacing the valve should have fixed the problem and instead it didn't for the people who gave it a try.
So now I'm a bit puzzled although firmly convinced to apply the correction.
I'm not an engineer, just a doctor with a passion for cars and mechanics, but I don't get well along with things I do not understand and this is one of them 🤦.
If anyone can explain me all the things I don't grasp in this mess I'll be very grateful 😁
And a huge thank you to all of the experienced guys who contribute here and help us to avoid shops to throw useless new and expensive parts in our cars...
Warm regards from Italy
Salvo
08-15-23, 07:08 AM
#224
I had no rattling noise with my 2000 RX300. I had oil consumption and smoked on start-up. Both gone after the PCV direction swap. It has been ~3.5K miles since the swap at the end of November. No oil consumption or smoke after the swap. The car runs nice. The question of why it happened only after 100K miles is open.
08-15-23, 08:05 AM
#225
I thought it was possibly due to the baffles in the original design valve cover getting clogged up over time