Bogging Down On Acceleration...
09-05-16, 08:43 PM
#46
Instructor
Yes, I agree there probably are multiple variables involved. Hopefully, switching to TGMO synthetic and if needed an ECM "refresh" will solve the problem for most. I am still wondering whether this issue is restricted to some model years, say 2012 and older. In which case, there could be a connection to the engine management software that may have been resolved in 2013+ cars.
09-05-16, 08:54 PM
#47
Update. No issues since last oil change on Thursday. Did about 200 plus miles both city and highway.
The previous owner used 0-20 syn oil i used Amsoil 0-20 in Feb had the issue. Used 0-20 Pennzoil and no issue.
The debate continues.
The previous owner used 0-20 syn oil i used Amsoil 0-20 in Feb had the issue. Used 0-20 Pennzoil and no issue.
The debate continues.
09-06-16, 10:08 AM
#48
Just an fyi, I just had to add a quart of oil after putting on around 5000 miles. Before I added I had no hesitation, after adding the quart I had hesitation for a couple of days before it went away ?????????
09-07-16, 04:07 PM
#51
Dr. Jekyll - Does your 2014 still have low miles? My 2010 has only 26k miles. I think partly I haven't had this problem because of the low miles.
The theory about adding petroleum oil instead of synthetic ... well, that's the most logical theory I've read yet. My first oil change I ran NON synthetic, but I had no issues. I think the lack of problems was in part due to low miles.
A knock sensor must have to be a very sensitive device. The addition of new oil could have a substantial difference in transmitting ... sound (I guess is the best way to describe it) versus the dirty oil removed. As "dirt" accumulates in oil, it's ability to transmit sound logically should diminish. And two, the difference between synthetic oil and petroleum may have a difference in the ability to transmit sound. That makes more sense than anything I've read so far.
The theory about adding petroleum oil instead of synthetic ... well, that's the most logical theory I've read yet. My first oil change I ran NON synthetic, but I had no issues. I think the lack of problems was in part due to low miles.
A knock sensor must have to be a very sensitive device. The addition of new oil could have a substantial difference in transmitting ... sound (I guess is the best way to describe it) versus the dirty oil removed. As "dirt" accumulates in oil, it's ability to transmit sound logically should diminish. And two, the difference between synthetic oil and petroleum may have a difference in the ability to transmit sound. That makes more sense than anything I've read so far.
09-12-16, 05:02 PM
#53
Sorry buddy... some of us just gave up :-(
I worked with RoadFrog and some others for about 18 months to troubleshoot my '07 with these same symptoms. We tried cleaners and different oils and voodoo/prayers but no snake oil fixed it and Lexus didn't have a solution.
When it came down to it, I finally convinced myself (using bluetooth engine monitoring software etc. that showed the engine was retarding ignition timing massively under certain conditions) that the engine had the TSIB-documented valve guide issue. That TSIB basically says there's play/rattle/noise in some valves and the engine knock sensor tells the computer to pull timing erroneously. The fix is to replace the cylinder heads, which costs $10k +. Having no warranty, I weighed that against the cost of getting a newer model that doesn't exhibit that problem and I purchased a 2011 LS. I love my new 2011, but I sure wish I had purchased a warranty on that '07 - it would have saved me a ton of money (bushings, motor mount, this engine crap etc.) :-(
When it came down to it, I finally convinced myself (using bluetooth engine monitoring software etc. that showed the engine was retarding ignition timing massively under certain conditions) that the engine had the TSIB-documented valve guide issue. That TSIB basically says there's play/rattle/noise in some valves and the engine knock sensor tells the computer to pull timing erroneously. The fix is to replace the cylinder heads, which costs $10k +. Having no warranty, I weighed that against the cost of getting a newer model that doesn't exhibit that problem and I purchased a 2011 LS. I love my new 2011, but I sure wish I had purchased a warranty on that '07 - it would have saved me a ton of money (bushings, motor mount, this engine crap etc.) :-(
09-13-16, 12:09 PM
#54
I worked with RoadFrog and some others for about 18 months to troubleshoot my '07 with these same symptoms. We tried cleaners and different oils and voodoo/prayers but no snake oil fixed it and Lexus didn't have a solution.
When it came down to it, I finally convinced myself (using bluetooth engine monitoring software etc. that showed the engine was retarding ignition timing massively under certain conditions) that the engine had the TSIB-documented valve guide issue. That TSIB basically says there's play/rattle/noise in some valves and the engine knock sensor tells the computer to pull timing erroneously. The fix is to replace the cylinder heads, which costs $10k +. Having no warranty, I weighed that against the cost of getting a newer model that doesn't exhibit that problem and I purchased a 2011 LS. I love my new 2011, but I sure wish I had purchased a warranty on that '07 - it would have saved me a ton of money (bushings, motor mount, this engine crap etc.) :-(
When it came down to it, I finally convinced myself (using bluetooth engine monitoring software etc. that showed the engine was retarding ignition timing massively under certain conditions) that the engine had the TSIB-documented valve guide issue. That TSIB basically says there's play/rattle/noise in some valves and the engine knock sensor tells the computer to pull timing erroneously. The fix is to replace the cylinder heads, which costs $10k +. Having no warranty, I weighed that against the cost of getting a newer model that doesn't exhibit that problem and I purchased a 2011 LS. I love my new 2011, but I sure wish I had purchased a warranty on that '07 - it would have saved me a ton of money (bushings, motor mount, this engine crap etc.) :-(
09-13-16, 02:49 PM
#55
Lexus Fanatic
09-22-16, 03:38 PM
#56
Driver School Candidate
I just took my LS460 2007in for bogging down. They recalibrate ECU and no bogging issues for the last 30 miles on the way home from dealer. I do seem to hear a "roaring" noise when I accelerate. Strange
09-22-16, 05:04 PM
#57
Instructor
I worked with RoadFrog and some others for about 18 months to troubleshoot my '07 with these same symptoms. We tried cleaners and different oils and voodoo/prayers but no snake oil fixed it and Lexus didn't have a solution.
When it came down to it, I finally convinced myself (using bluetooth engine monitoring software etc. that showed the engine was retarding ignition timing massively under certain conditions) that the engine had the TSIB-documented valve guide issue. That TSIB basically says there's play/rattle/noise in some valves and the engine knock sensor tells the computer to pull timing erroneously. The fix is to replace the cylinder heads, which costs $10k +. Having no warranty, I weighed that against the cost of getting a newer model that doesn't exhibit that problem and I purchased a 2011 LS. I love my new 2011, but I sure wish I had purchased a warranty on that '07 - it would have saved me a ton of money (bushings, motor mount, this engine crap etc.) :-(
When it came down to it, I finally convinced myself (using bluetooth engine monitoring software etc. that showed the engine was retarding ignition timing massively under certain conditions) that the engine had the TSIB-documented valve guide issue. That TSIB basically says there's play/rattle/noise in some valves and the engine knock sensor tells the computer to pull timing erroneously. The fix is to replace the cylinder heads, which costs $10k +. Having no warranty, I weighed that against the cost of getting a newer model that doesn't exhibit that problem and I purchased a 2011 LS. I love my new 2011, but I sure wish I had purchased a warranty on that '07 - it would have saved me a ton of money (bushings, motor mount, this engine crap etc.) :-(
https://www.yourmechanic.com/article...y-knock-sensor
Engine oil and knock discussion/that fresh new oil is noisy
http://forums.fourtitude.com/showthread.php?2124631-Correlation-between-knock-voltages-and-viscosity-of-motor-oil
Last edited by superdenso; 09-22-16 at 05:52 PM.
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