Reengineered rear valve cover??
08-15-23, 08:51 AM
#226
Moderator
too many things noise, oil consumption and mpg
My first question is ..
Is the check engine light working and do you have any error codes?
Next is ..
Are you upto date with maintenance per warranty book? Specially spark plugs and air filter timing belt and timing belt train components. Many of these are sealed and do not get lubricated as they are used .. resulting in noisy components.
Some brutal comments and observations, so please do not be offended.
The vehicle was guaranteed for first 60thousand miles and 6 yrs when the speed limit was 55mph with emission standards at that time. Slow and go 18mpg and down to 15 at high speed.
My speculations:
Based on above the engine rpms during operation were expected to be below 2500 rpms during cruising. [sustained over a longer period]. The oil drain tubes , that take the pumped oil from the top of the engine were thinned down [balance between volume of pumped oil, temp or operation, rate of drain down etc].
imho with higher than designed target speed oil is not draining down fast enough and is getting pooled in the valve cover bank of the pcv, resulting in being sucked in at the intake.
For the noise, you need a mechanic to narrow down the source. They use stethoscope to listen. My guess is issue with the drive train of timing belt or even the injectors.
Newer model RX has 6 or 8 speed transmission with their own set of pros and cons.
At the end the first gen RX is now 20+ yrs old. The vehicles back then were designed and sold for 6 yrs of life. When I bough mine, my expectations were 100K miles of trouble free service and mine was running flawless for 2.5x my expectations and likely would have lasted 5x. I still see first gen RX on road while all competitor offerings have been long gone.
Salim
Is the check engine light working and do you have any error codes?
Next is ..
Are you upto date with maintenance per warranty book? Specially spark plugs and air filter timing belt and timing belt train components. Many of these are sealed and do not get lubricated as they are used .. resulting in noisy components.
Some brutal comments and observations, so please do not be offended.
The vehicle was guaranteed for first 60thousand miles and 6 yrs when the speed limit was 55mph with emission standards at that time. Slow and go 18mpg and down to 15 at high speed.
My speculations:
Based on above the engine rpms during operation were expected to be below 2500 rpms during cruising. [sustained over a longer period]. The oil drain tubes , that take the pumped oil from the top of the engine were thinned down [balance between volume of pumped oil, temp or operation, rate of drain down etc].
imho with higher than designed target speed oil is not draining down fast enough and is getting pooled in the valve cover bank of the pcv, resulting in being sucked in at the intake.
For the noise, you need a mechanic to narrow down the source. They use stethoscope to listen. My guess is issue with the drive train of timing belt or even the injectors.
Newer model RX has 6 or 8 speed transmission with their own set of pros and cons.
At the end the first gen RX is now 20+ yrs old. The vehicles back then were designed and sold for 6 yrs of life. When I bough mine, my expectations were 100K miles of trouble free service and mine was running flawless for 2.5x my expectations and likely would have lasted 5x. I still see first gen RX on road while all competitor offerings have been long gone.
Salim
08-15-23, 09:35 AM
#227
08-15-23, 09:34 PM
#228
Moderator
The other could be a build difference in baffles to restrict liquid (oil) while still allowing fuel vapor recovery.
Finally, my vehicle did not burn any oil so my information is not first hand .... basically speculation based and what makes sense to me. That implies it can be flawed.
Salim
08-16-23, 12:07 AM
#229
Lexus Champion
This engine will sludge even running synthetic oil* I've seen this myself. Shorter trips cause the oil to harden and turn to goop it is a slow process and you'll never notice until the engine starts running poorly due to clogged rings etc.
* not all synthetic oils are great some are average and still suffer breakdown in this engine. I personally am not impressed with Mobil 1 at all, it is everywhere and for this reason many people use it.
* not all synthetic oils are great some are average and still suffer breakdown in this engine. I personally am not impressed with Mobil 1 at all, it is everywhere and for this reason many people use it.
08-16-23, 01:56 AM
#230
5th Gear
Join Date: Aug 2023
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This engine will sludge even running synthetic oil* I've seen this myself. Shorter trips cause the oil to harden and turn to goop it is a slow process and you'll never notice until the engine starts running poorly due to clogged rings etc.
* not all synthetic oils are great some are average and still suffer breakdown in this engine. I personally am not impressed with Mobil 1 at all, it is everywhere and for this reason many people use it.
* not all synthetic oils are great some are average and still suffer breakdown in this engine. I personally am not impressed with Mobil 1 at all, it is everywhere and for this reason many people use it.
Having said that, I take all of your thoughts but let me narrow a bit the situation:
no CEL. No error codes. Maintenance was performed as per schedule (or at least this is what I know).
I did timing belt and spark plugs at the correct time but since they are close to the replacement time I'll do them both together with the cover job.
I read oil consumption and mpg are strictly related so maybe they both will be fixed by the cover job.
Not so sure about the rattling noise, but again I read it's knocking that other people who had the problem said it was carbon residuals in the chamber which triggered anticipated burning of the fuel/air mix.
They suggested a fix with PEA additive, which I did but with no results.
This bothers me since it can damage pistons...
As for expected use, I understand the car was built to run lower average rpms but here in Italy we used to have higher speed limits than the US (not anymore now) so since mostly original use was highway at a bit more of 3.000 rpms, you can say I used it out of the expected boundaries for the first 100k miles. That's why I don't understand how's possible the problem didn't rise up before...
As for oil, if that is the case, even with synthetic oil I can expect to find sludge. So question now is in your experience which cleaning treatment is the best before going for the full service and the valve cover replacement?
Lastly let me explain my position, I love this car, I'm the first owner and I would like to maintain it in perfect (as possible) shape. I'm an old timers and ancient cars enthusiast, I have several, but since this was my first new car, bought when I begun my career and got married, she holds an important place in my "heart", that's why I want her to be in the best possible shape and that's why I didn't trade her in or sell after a while, as instead I did with all other new cars I bought in all these years.
I still owe the first car my father bought in my very same situation: it's a 1961 Alfa Romeo Giulietta 1.3 Ti.
Just a bit of my background to make you understand my motivation, which is more "affective" than oriented to squeeze all that I can from her before she comes apart...
Warm regards guys and sorry for being so verbose and probably annoying you...
Salvo
Last edited by ssgroi; 08-16-23 at 01:59 AM.
08-16-23, 08:24 AM
#232
Moderator
Ok so, first of all, no offense ever, I'm asking for your help/opinion and that means you guys spend time answering my questions, so you don't need to pay attention to be "politically correct"
Having said that, I take all of your thoughts but let me narrow a bit the situation:
no CEL. No error codes. Maintenance was performed as per schedule (or at least this is what I know).
I did timing belt and spark plugs at the correct time but since they are close to the replacement time I'll do them both together with the cover job.
I read oil consumption and mpg are strictly related so maybe they both will be fixed by the cover job.
Not so sure about the rattling noise, but again I read it's knocking that other people who had the problem said it was carbon residuals in the chamber which triggered anticipated burning of the fuel/air mix.
They suggested a fix with PEA additive, which I did but with no results.
This bothers me since it can damage pistons...
As for expected use, I understand the car was built to run lower average rpms but here in Italy we used to have higher speed limits than the US (not anymore now) so since mostly original use was highway at a bit more of 3.000 rpms, you can say I used it out of the expected boundaries for the first 100k miles. That's why I don't understand how's possible the problem didn't rise up before...
As for oil, if that is the case, even with synthetic oil I can expect to find sludge. So question now is in your experience which cleaning treatment is the best before going for the full service and the valve cover replacement?
Lastly let me explain my position, I love this car, I'm the first owner and I would like to maintain it in perfect (as possible) shape. I'm an old timers and ancient cars enthusiast, I have several, but since this was my first new car, bought when I begun my career and got married, she holds an important place in my "heart", that's why I want her to be in the best possible shape and that's why I didn't trade her in or sell after a while, as instead I did with all other new cars I bought in all these years.
I still owe the first car my father bought in my very same situation: it's a 1961 Alfa Romeo Giulietta 1.3 Ti.
Just a bit of my background to make you understand my motivation, which is more "affective" than oriented to squeeze all that I can from her before she comes apart...
Warm regards guys and sorry for being so verbose and probably annoying you...
Salvo
Having said that, I take all of your thoughts but let me narrow a bit the situation:
no CEL. No error codes. Maintenance was performed as per schedule (or at least this is what I know).
I did timing belt and spark plugs at the correct time but since they are close to the replacement time I'll do them both together with the cover job.
I read oil consumption and mpg are strictly related so maybe they both will be fixed by the cover job.
Not so sure about the rattling noise, but again I read it's knocking that other people who had the problem said it was carbon residuals in the chamber which triggered anticipated burning of the fuel/air mix.
They suggested a fix with PEA additive, which I did but with no results.
This bothers me since it can damage pistons...
As for expected use, I understand the car was built to run lower average rpms but here in Italy we used to have higher speed limits than the US (not anymore now) so since mostly original use was highway at a bit more of 3.000 rpms, you can say I used it out of the expected boundaries for the first 100k miles. That's why I don't understand how's possible the problem didn't rise up before...
As for oil, if that is the case, even with synthetic oil I can expect to find sludge. So question now is in your experience which cleaning treatment is the best before going for the full service and the valve cover replacement?
Lastly let me explain my position, I love this car, I'm the first owner and I would like to maintain it in perfect (as possible) shape. I'm an old timers and ancient cars enthusiast, I have several, but since this was my first new car, bought when I begun my career and got married, she holds an important place in my "heart", that's why I want her to be in the best possible shape and that's why I didn't trade her in or sell after a while, as instead I did with all other new cars I bought in all these years.
I still owe the first car my father bought in my very same situation: it's a 1961 Alfa Romeo Giulietta 1.3 Ti.
Just a bit of my background to make you understand my motivation, which is more "affective" than oriented to squeeze all that I can from her before she comes apart...
Warm regards guys and sorry for being so verbose and probably annoying you...
Salvo
Oil loss:
Drip/seepage/leaks Check floor where parked, check with light all around the engine, check intermix with coolant.
Burn:
Through intake or by the rings. By the rings typically will leave a trace of soot at the back end ... where the exhaust gases are let go. You can do the compression test.
By the intake is through PCV passage. Put a catch-can in line with the PCV to intake. If the can fills up then try the new valve cover.
There may be gelling of oil that is preventing proper drain down or even continued condensing of oil.
As I am aging and some day may have to make decision on how to extend my life. In non stressful environment my choice is look at the consequences of post procedure (repair) quality of life and expense to do the procedure. Back to cars ... I look at function and cost. Not to hijack the discussion in 3rd Gen RX some folks complain about timing cover oil leak. I say just add the lost oil as it is not worth dropping the engine to address the problem.
YMMV.
Salim
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