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noise from the engine when car turns on but not the engine
This is about a month after I owned my NX I realized that when the car is turned on (without the engine), I hear a constant beep noise from the front of the car. This noise cannot be heard if you are inside the car but only if you are outside. I was playing around with my car settings one day in my garage and noticed the noise.
Has anyone experienced this? or know what I am talking about?
This is about a month after I owned my NX I realized that when the car is turned on (without the engine), I hear a constant beep noise from the front of the car. This noise cannot be heard if you are inside the car but only if you are outside. I was playing around with my car settings one day in my garage and noticed the noise.
Has anyone experienced this? or know what I am talking about?
I think I am having this issue as well, have you had any more input on resolution on this?
Reviving this thread to see if anyone can confirm if this normal or not. My wife has a 2016 NX200T and I noticed the sound recently. Not sure if it was there all along as I have been around it more often lately changing the oil and doing some maintenance as its been a year since we bought it. I have a GS200t with the same engine and I don't hear anything of this caliber under this scenario.
As described above, there is a higher pitched buzzing/humming from the engine bay that only occurs when the vehicle is in Ignition On mode and the engine is not running. It almost sounds like an HID ballast as it warms up. I don't believe I hear it once the engine starts. The sound will occur the entire time the vehicle is in the Ignition On mode. It seems to be louder from under the vehicle and I can actually feel a corresponding vibration in from the transmission pan but not the oil pan or anywhere else. I am almost wondering if this is something from the starter or transmission itself, but hard to tell.
Thanks for any input! I can post a video as well once I have the car back.
Thanks for the info, It didnt initially sound like it was coming from the area where the pump is located but it definitely does sound like a small pump motor running. I'll break out the stethoscope to try to pinpoint it better.
What I am mainly trying to determine at this point is if this is normal. Do you have an NX and if so, is it displaying this behavior?
pretty sure it’s the humm coming from the electric motor for the inter cooler, as stated above.
I really appreciate the response. So this is only during the Ignition On phase, correct?
I poked around this morning with the stethoscope and I couldn't pinpoint the noise from the area of the electric water pump. Whats so odd is that the transmission pan is somehow carrying the sound the loudest and has a tangible vibration. My GS does not make that sound but has the same engine so its placing a lot doubt in my mind. As long as its occurring on other vehicles, that sounds good to me!
On my NX300, the faint hum with ignition On appears to originate near the passenger side headlamp, well forward of the coolant reservoir. This is a long way from the transmission pan, which is on the opposite side of the vehicle. So I am tending to conclude you are hearing something else, that is dominant. Best I can offer is a WAG (wild-a** guess).
Most modern transmissions regulate fluid pressure to the internal hydraulic control valves (called "line pressure") by means of an electric solenoid valve that is pulsed on and off. If the on and off cycles are similar in duration, the pump pressure will be reduced by about 50%. The ratio of on/off times is varied by the transmission computer, based on input from a pressure sensor, to regulate internal line pressure. Typical pulse rates are in the range 100 - 200 pulses per second. When the transmission input shaft is not turning, pump pressure should be zero, so no regulator solenoid pulsing is required. My theory is a pressure sensor fault has "fooled" the transmission computer into "thinking" the internal line pressure is too high. Have you noticed any subtle changes in shift characteristics?
In the attached image, item #18 is the line pressure regulator solenoid, which is mounted in the vicinity of the pan.
On my NX300, the faint hum with ignition On appears to originate near the passenger side headlamp, well forward of the coolant reservoir. This is a long way from the transmission pan, which is on the opposite side of the vehicle. So I am tending to conclude you are hearing something else, that is dominant. Best I can offer is a WAG (wild-a** guess).
Most modern transmissions regulate fluid pressure to the internal hydraulic control valves (called "line pressure") by means of an electric solenoid valve that is pulsed on and off. If the on and off cycles are similar in duration, the pump pressure will be reduced by about 50%. The ratio of on/off times is varied by the transmission computer, based on input from a pressure sensor, to regulate internal line pressure. Typical pulse rates are in the range 100 - 200 pulses per second. When the transmission input shaft is not turning, pump pressure should be zero, so no regulator solenoid pulsing is required. My theory is a pressure sensor fault has "fooled" the transmission computer into "thinking" the internal line pressure is too high. Have you noticed any subtle changes in shift characteristics?
In the attached image, item #18 is the line pressure regulator solenoid, which is mounted in the vicinity of the pan.
Thanks I greatly the appreciate all of the info. I haven't noticed any issues but I don't drive the car very often. No complaints from my wife either.
I think its time to invest in a Techstream setup to see if I can pull any codes. You seem like the type of person who would have that, if so, can you offer any guidance on the best route to go? I don't mind paying for that temporary license I have read about.
It is indeed ironic that you have asked about Techstream. I purchased an inexpensive laptop running Windows XP so I could dedicate it to Techstream without having to hack the operating system. However, I never purchased the special interface cable and software because I later decided this would be my first and last Lexus product, and I would trade in in the the end of the 4 year new vehicle warranty period. I unfortunately have had the misfortune to receive a defective sample that consumes a quart of oil every 500 miles and drips oil after shutdown that has pooled in the decorative tailpipe trim cups during operation. To prevent oil stains on the garage floor, I either have to scoop out the oil or place cardboard under the rear bumper (I chose the latter option). Lexus response is a quart per 500 miles is "within acceptable parameters" and, because there are no fault codes stored, there is nothing to repair. This vehicle (model year 2019) has less than 5000 miles on the odometer. My concern is the catalytic converter will be destroyed by excess oil and fail immediately after the warranty expires, at which point Lexus will deny any responsibility because I continued to drive it with a known oil consumption issue. It's a classic "catch-22" situation.
It is indeed ironic that you have asked about Techstream. I purchased an inexpensive laptop running Windows XP so I could dedicate it to Techstream without having to hack the operating system. However, I never purchased the special interface cable and software because I later decided this would be my first and last Lexus product, and I would trade in in the the end of the 4 year new vehicle warranty period. I unfortunately have had the misfortune to receive a defective sample that consumes a quart of oil every 500 miles and drips oil after shutdown that has pooled in the decorative tailpipe trim cups during operation. To prevent oil stains on the garage floor, I either have to scoop out the oil or place cardboard under the rear bumper (I chose the latter option). Lexus response is a quart per 500 miles is "within acceptable parameters" and, because there are no fault codes stored, there is nothing to repair. This vehicle (model year 2019) has less than 5000 miles on the odometer. My concern is the catalytic converter will be destroyed by excess oil and fail immediately after the warranty expires, at which point Lexus will deny any responsibility because I continued to drive it with a known oil consumption issue. It's a classic "catch-22" situation.
Did you go to another dealer and relentlessly call and email corporate? Is it a turbocharger issue? I cant see how they can ignore the visible oil leakage.
Yes, made an appointment with another Dealer and phoned Lexus, USA Customer Service (800-255-3987). Both were an exercise in futility.
There is only one Lexus dealer in my state, so I took the NX to a dealer in a neighboring state for evaluation. The service manager there was quite pleasant, but unable or unwilling to help. The first thing he did was look up the name of the Dealer who delivered the vehicle, and then went to his office to phone them "to obtain some history". After returning, he informed me he had discussed the vehicle with the service manager there, and agreed with their findings. He did offer to perform a comprehensive diagnostics scan for $232.50, but advised it would probably be a waste of my money since no relevant codes would be found, and without codes, it is not possible to obtain warranty service approval from Lexus. He was not impressed by the fresh puddles of oil in the tailpipe trim rings, commenting that "all turbocharged engines consume oil".
The person I spoke to at Lexus USA was very pleasant as well. She essentially informed me my local Dealer was authorized to handle all customer service concerns. In other words, "Don't call us, we're not interested unless you are seeking to purchase a new Lexus".
This is a stark contrast to the great service and quality experience I had with my 2005 Avalon, which I owned for 14 years after purchasing new.. My impression is Toyota vehicle quality and customer service are both vastly superior to Lexus.
Yes, made an appointment with another Dealer and phoned Lexus, USA Customer Service (800-255-3987). Both were an exercise in futility.
There is only one Lexus dealer in my state, so I took the NX to a dealer in a neighboring state for evaluation. The service manager there was quite pleasant, but unable or unwilling to help. The first thing he did was look up the name of the Dealer who delivered the vehicle, and then went to his office to phone them "to obtain some history". After returning, he informed me he had discussed the vehicle with the service manager there, and agreed with their findings. He did offer to perform a comprehensive diagnostics scan for $232.50, but advised it would probably be a waste of my money since no relevant codes would be found, and without codes, it is not possible to obtain warranty service approval from Lexus. He was not impressed by the fresh puddles of oil in the tailpipe trim rings, commenting that "all turbocharged engines consume oil".
The person I spoke to at Lexus USA was very pleasant as well. She essentially informed me my local Dealer was authorized to handle all customer service concerns. In other words, "Don't call us, we're not interested unless you are seeking to purchase a new Lexus".
This is a stark contrast to the great service and quality experience I had with my 2005 Avalon, which I owned for 14 years after purchasing new.. My impression is Toyota vehicle quality and customer service are both vastly superior to Lexus.
I would keep calling corporate and tell them the dealer is not addressing your concerns. Maybe you can also swing by an independent specialist and get their opinion.
I did get Techstream up and running on my GS, will try the NX and see if I can find anything out of the ordinary. It has some cool detail on transmission solenoids and just about everything else. You can also activate anything manually such as the intercooler water pump, air pump etc..
I bought the $40 cable on Amazon then bought the 2 day license. Still worth it since I'm using it to adjust some custom features on both cars.
Yes, made an appointment with another Dealer and phoned Lexus, USA Customer Service (800-255-3987). Both were an exercise in futility.
There is only one Lexus dealer in my state, so I took the NX to a dealer in a neighboring state for evaluation. The service manager there was quite pleasant, but unable or unwilling to help. The first thing he did was look up the name of the Dealer who delivered the vehicle, and then went to his office to phone them "to obtain some history". After returning, he informed me he had discussed the vehicle with the service manager there, and agreed with their findings. He did offer to perform a comprehensive diagnostics scan for $232.50, but advised it would probably be a waste of my money since no relevant codes would be found, and without codes, it is not possible to obtain warranty service approval from Lexus. He was not impressed by the fresh puddles of oil in the tailpipe trim rings, commenting that "all turbocharged engines consume oil".
The person I spoke to at Lexus USA was very pleasant as well. She essentially informed me my local Dealer was authorized to handle all customer service concerns. In other words, "Don't call us, we're not interested unless you are seeking to purchase a new Lexus".
This is a stark contrast to the great service and quality experience I had with my 2005 Avalon, which I owned for 14 years after purchasing new.. My impression is Toyota vehicle quality and customer service are both vastly superior to Lexus.
Has any of the dealers you took the car to removed the turbocharger from the car and inspected it? If you have puddles of oil at the end of the exhaust pipe, it’s probably a seal in the hot side of the turbocharger leaking. If there is no oil on the input of the hot side, but fresh oil on the output port, it should be obvious. Not all turbocharged engines use oil. Our NX doesn’t use any, it has 40K miles on it. The F150 I had with the twin turbos did not use any either.
On my NX300, the faint hum with ignition On appears to originate near the passenger side headlamp, well forward of the coolant reservoir. This is a long way from the transmission pan, which is on the opposite side of the vehicle. So I am tending to conclude you are hearing something else, that is dominant. Best I can offer is a WAG (wild-a** guess).
Most modern transmissions regulate fluid pressure to the internal hydraulic control valves (called "line pressure") by means of an electric solenoid valve that is pulsed on and off. If the on and off cycles are similar in duration, the pump pressure will be reduced by about 50%. The ratio of on/off times is varied by the transmission computer, based on input from a pressure sensor, to regulate internal line pressure. Typical pulse rates are in the range 100 - 200 pulses per second. When the transmission input shaft is not turning, pump pressure should be zero, so no regulator solenoid pulsing is required. My theory is a pressure sensor fault has "fooled" the transmission computer into "thinking" the internal line pressure is too high. Have you noticed any subtle changes in shift characteristics?
In the attached image, item #18 is the line pressure regulator solenoid, which is mounted in the vicinity of the pan.
Techstream is showing that when the vehicle ignition is in the Ignition On position and the engine not running, the SLT solenoid is on. The solenoid is also on when the engine is running. There are no codes shown so I am still not sure if this is normal or not. Everything behaves normally while driving. I searched through the Techstream service manual and couldn't find any documentation on that solenoid running while the engine is off.
I am not 100% if that is the noise but based where I can hear and feel it, it makes sense so far.
EDIT: Tested on another NX200t and the exact same sound is present, I think I'll write this off as normal.
08-30-17, 09:15 AM
noise from the engine when car turns on but not the engine
