Engine knock at cold startup - RX450H
05-18-16, 01:13 PM
#1
Driver School Candidate
Thread Starter
Engine knock at cold startup - RX450H
It almost sounds like somebody is taking a small hammer and banging at the plastic cover on top the engine when the vehicle is started new from cold.
After about 8 or 9 knocks it goes away.
Taking it to a dealer soon to get it checked.
Has anybody else experienced this?
2010 Model year. 81k miles.
I have only owned it for a month.
After about 8 or 9 knocks it goes away.
Taking it to a dealer soon to get it checked.
Has anybody else experienced this?
2010 Model year. 81k miles.
I have only owned it for a month.
Last edited by fj40drm; 05-19-16 at 05:08 AM.
05-19-16, 05:09 AM
#3
Driver School Candidate
Thread Starter
05-19-16, 07:10 AM
#4
Lead Lap
You may be experiencing gear backlash noise in the planetary gears as a result of momentary rough idle speed variation of the engine (with MG1 spinning and MG2 stationary - and the two planetary gear sets alternating torque direction).
Doesn't it immediately disappear once putting the car into gear (either FWD or REV) - which would inherently apply enough load (on MG1) to keep the gear(s) loaded in one direction?
Doesn't it immediately disappear once putting the car into gear (either FWD or REV) - which would inherently apply enough load (on MG1) to keep the gear(s) loaded in one direction?
05-19-16, 09:27 AM
#6
Racer
Oil pressure delay for the VVTi system (valve timing) could cause this. Happened to me for a couple days after having an oil change done, assumed it was a bit of dislodged gunk that got in the way. Even threw a check engine code (which is how I knew it was low oil pressure for VVTi). But after a few starts it went away (except for 1 time starting up in extreme cold) so I assumed the gunk got cleared away.
If dealer doesn't help, my backup advice would be to try an oil/filter change, or switch to a synthetic oil if you aren't currently using..
If dealer doesn't help, my backup advice would be to try an oil/filter change, or switch to a synthetic oil if you aren't currently using..
05-19-16, 10:27 AM
#7
Lead Lap
That was one of my first thoughts, too; only the VVTi, when functioning correctly, locks the intake cams in full retard, and the exhaust cams in full advance via pins when shutting down the engine (to assure "proper" setting at start-up) - yet a number of YouTube videos highlight worn VVTs and associated noise (however, IIRC, they're noisy during warmed running and not at cold start).
Regardless, all of the associated moving parts requiring clean oil are of primary concern for me to ensure clean passageways - for which I change the (0w20 Synthetic) oil/filter at 5K intervals as a makes-me-feel-useful preventative basis.
Regardless, all of the associated moving parts requiring clean oil are of primary concern for me to ensure clean passageways - for which I change the (0w20 Synthetic) oil/filter at 5K intervals as a makes-me-feel-useful preventative basis.
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10-03-16, 11:42 AM
#8
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My 2010 rx450h has the exact same problem. It has 51k miles, and the dealer has been trying to diagnose the problem for 3 days. Did they find out what was wrong with the car?
10-04-16, 04:51 PM
#9
Now, that is interesting. Same vehicle, same issue, and the dealer hasn't a clue? Please be sure to let us know what they find out. Also, I would encourage you to go to a good Japanese import indie for diagnosis. Both cars are out of warranty, and I don't think you will be thrilled to see the dealer price for repairs, regardless of what is wrong (assuming they can find out what is wrong). Sometimes, independent shop people see more of the problems that crop up on out-of-warranty vehicles, for obvious reasons. May be more familiar with this issue.
10-07-16, 02:54 PM
#10
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Got it back from the dealer. They said that the injectors and gaskets need to be replaced for 2200. Its hard to believe that I need injectors, since the car only has 51k miles and no engine fault codes. I just bought a bottle of redline si-1 fuel cleaner. Maybe that will do the trick.
12-05-16, 06:21 PM
#11
engine noise
That noise is what mechanics call dry start . It's basically starting the car while the oil has a delay on lubricating the rod bearing and it causes a slight second of piston slap. I don't understand why it does it but my Ls430 does it sometimes and other times it doesnt. I'm thinking it's the temperature outside and it also depends on your old conditions. If you start it up and it makes the knock while a engine oil light on,you have a problem .
12-05-16, 06:31 PM
#12
engine knock
I have a friend who had a brand new Toyota Camry that had engine knock constantly . He told me that he had took it to the dealer and they said it was normal . I called it bs . I have never heard a brand new car with engine noise as loud as his Camry . Then again I've listen to a few new design toyota cars and the noise seems alike. I can tell you that I have never heard of a Toyota Lexus motor failing under 200k miles with proper care. I can also say that the Toyota v8 seems to have more of the lifter and engine noise dued to their design . Overall they're really reliable when it comes to engine and transmission problems.
12-22-16, 07:59 PM
#13
Got it back from the dealer. They said that the injectors and gaskets need to be replaced for 2200. Its hard to believe that I need injectors, since the car only has 51k miles and no engine fault codes. I just bought a bottle of redline si-1 fuel cleaner. Maybe that will do the trick.
https://www.clublexus.com/forums/hyb...anty-work.html - Check out the photos on the injector here...
https://www.clublexus.com/forums/hyb...t-came-on.html
TSB L-SB-0045-12 - Replaced 6 fuel injectors
23209-31160
23291-28020 - insulators
25627-31030 - EGR gasket
17179-31010 - Intake manif gasket
17176-0P021 - Air Surge gasket
12-26-16, 06:48 AM
#14
engine noise
[QUOTE=rsutoratos;9714950]Someone said injectors ? If it knocks really hard, its the TSB, happened to me a 79k and again at 115k.. I'm at 126k now. Luckily I had extended warranty, cost a bundle if its was out...
https://www.clublexus.com/forums/hyb...anty-work.html - Check out the photos on the injector here...
https://www.clublexus.com/forums/hyb...t-came-on.html
TSB L-SB-0045-12 - Replaced 6 fuel injectors
23209-31160
23291-28020 - insulators
25627-31030 - EGR gasket
17179-31010 - Intake manif gasket
17176-0P021 - Air Surge gasket[/QUOTE. If the noise is a slight tap ,then it could be injector. I still highly doubt it . If it's making the noise for a few second then you might have to check your oil weight and condition of it. If that noise goes on every time you start the car ,and imagine if you start the car ten times a day. This will usually cause premature wear on the rod bearing no question ask . I been a mechanic for 20 years working on Hondas ,and I know their variable valve timing engine are known for dry start . I would be concern if I had less then 100k miles ,then again it shouldn't do this even at 200k miles .
https://www.clublexus.com/forums/hyb...anty-work.html - Check out the photos on the injector here...
https://www.clublexus.com/forums/hyb...t-came-on.html
TSB L-SB-0045-12 - Replaced 6 fuel injectors
23209-31160
23291-28020 - insulators
25627-31030 - EGR gasket
17179-31010 - Intake manif gasket
17176-0P021 - Air Surge gasket[/QUOTE. If the noise is a slight tap ,then it could be injector. I still highly doubt it . If it's making the noise for a few second then you might have to check your oil weight and condition of it. If that noise goes on every time you start the car ,and imagine if you start the car ten times a day. This will usually cause premature wear on the rod bearing no question ask . I been a mechanic for 20 years working on Hondas ,and I know their variable valve timing engine are known for dry start . I would be concern if I had less then 100k miles ,then again it shouldn't do this even at 200k miles .
01-25-17, 06:29 PM
#15
My was knocking like a **** on startup, and while sitting in traffic the car goes from hybrid to gas, the whole car gets loud bang and extreme shakes. It sounded like the car was going to blow up... my rx is lexus dealer maintain, since they fixed all the issue under warranty/extended warranty I dont really care at this point.. as I have 3 days left with my rx.. traded it for a MDX