Hi

I'm the owner of 2016 RX 450H Premier ( Full specs).
During a cold startup i 'm getting a knocking sound and vibration for a few seconds and when the rpm of the engine increase the knock sound disappeared.
Attach is a video with the knocking sound.

Thanks!

 

All I can say is, wow. The fact it quickly goes away is very good news, but what on earth is happening for those first few seconds? Perhaps a dealer or an experienced mechanic with a stethoscope can narrow it down.

 

Thank you for your reply.

Yes, It is only for a few seconds until the rpm increase. I will try to schedule a meeting with the Lexus dealer.
I'm suspecting a problem with a fuel injector.Attach is a document i found from Lexus "Runs Rough on Cold Start"

 

See my thread from 8/13/19

 

Hi Nogee

I have check your thread on 8/13/19 and it's look like the same problem.

Did you manage to fix the issue?

3 weeks ago i took the car to the Lexus dealer in order to inspect and fix the problem, when they saw video they told me that the injectors need cleaning and this will fix the problem.
I paid 400 euro for the cleaning and i though that the problem was resolve, but after few days the vibration reappeared but not the knocking, so back to the dealer, again 4 days at the dealer replacing the sparks, check the EGR, clean again the injectors, but the vibration is still there.
At the end they told me that i need to replace the port injector x 6 in order to fix the problem, because now there is a new version of injectors which are better and are kept clean.

Today the knocking sound reappear again and i'm very disappointed.

​​​​​​ I will appreciate if some can help

Thanks!

 

Did you have any DTCs?

 

Hi
If i understand your are mentioning for logs from the Diagnostic tool.

No i do not have (DTCs).

The car was check at the LEXUS dealer.

Thanks!

 

Yes, the new injectors solved this long lasting issue. They did several tests with corporate assistance. They also looked into the car's log but nothing was found. They emphasized that nothing was amiss however, corporate allowed the dealer to fix the problem under warranty and all was resolved with new injectors. The car started fine and no stumbling while driving. Previously to this last visit to the dealer I had used fuel cleaners to resolve the issues without any improvement.

Good Luck

 

Thank You!!!

 

I finally replaced the 3 back injectors not the 6 ones, the price that payed for the injector cleaning was substracted from the total bill.