Cheers everyone!

I have a problem with my Lexus nx 200t 2017.
When car is idling in D I feel substantial vibration. When switched to N vibration goes away.
I replaced transmission mount with new one and vibration dissapeared for a couple of days but returned again. I checked the new mount and it seems to be OK.
I am starting to wonder if other mounts are damaged and put extra load on transmission mount.
Could you advise how can I solve this problem. it is getting on my nerves))

 

First off — Welcome to the Club and Congrats on your 1st post!!


That said — I have not had this issue and hope someone will chime in and offer helpful advice on what’s going on with your NX.

If you’re able to resolve the issue on your own, please provide what was found / diagnosed and how you were able to resolve it so we can pass on knowledge and helpful info for the next person.

Thanks much

 

When you say "idling in D" are you at a full stop with your foot on the brake?

If so, what do you experience when you have it in a lower gear, foot on the brake?
What about in REVERSE, foot on the brake?

The answers may help lead you to the root cause of the problem.

Also, what happens if you are in "D", on a clear (NO traffic) road, but do not give it any gas? In other words, just let the car move forward while in "D". Do you still feel the vibration?

How many miles on the vehicle?

 

Hi,

Thanks for reply. Vibrations appears when i press on brake when car in D and car is at full stop.

 

What do you experience when you have it in a lower gear, foot on the brake?
What about in REVERSE, foot on the brake?

The answers may help lead you to the root cause of the problem.

Also, what happens if you are in "D", on a clear (NO traffic) road, but do not give it any gas? In other words, just let the car move forward while in "D". Do you still feel the vibration?

How many miles on the vehicle?

 

I feel vibrations when car is stationary (foot on the brake) in D and R. N and P no vibration,moving car also has no vibration.When car is cold and operates on higher idling RPM there is no vibration when stopped and gear in D and R. Vehicle has 91k miles.

 

What is engine RPM when car is stationary ( foot on brake) in D and R and vibrations are being felt ?
Scanner reading is best/accurate but in its absence vehicle tach reading will do for now.
I'm assuming when tranny in N or P engine RPM increases and no vibration. What is engine RPM in this state?
Readings taken only after engine is thoroughly warmed up.
What is the difference in the two readings ?
Your RPM reading for a warm engine with tranny in D or R should be 600 RPM or a tad higher and increases to 650 w/tranny in N or P.
Numbers quoted above are not cast in stone but are generally valid as what a normal operating engine/tranny should behave after an initial warm up period.

 

When engine hot and stationary(car stopped stopped,foot on brake) in D engine RPM is about 600 as you mentioned. When in P and N 750 RPM. When cold and in D is about 650.

 

My '16 NX200t is in winter storage but coming back into service for the summer in the next couple of days. I'll check RPMs then for similarity with what you 're experiencing w/yours.
The jump from 600 to 750 seems high ( but I stand to be corrected ).

 

Vehicle off storage and took it for drive into town & back ( 60 mins total ).
This what I observed with my '16 NX200t:
- With a warm engine, RPM was 750 in P & N ( exactly like yours )
- Again with warm engine, RPM was high 600's and close to the 750 indicator mark on tach display. Conditions were: Brake ON, tranny in D or R. I did not connect my scanner while taking readings.
My guess on your condition:
- Warm engine RPM @ 600, brake ON, tranny in D or R and vibrations felt would suggest to me engine RPM too low and on cusp of torque converter engaging & disengaging producing said vibrations. To check this theory: - With warm engine, brake ON, tranny in D or R, increase engine RPM to 700 -750. If vibrations disappear we can conclude engine RPM is involved. Question is why engine ECU is not responding i.e. increasing RPM hence engine torque when a load ( tranny shifted to D or R w/brake ON) is present.
Did this vibration phenomenon just happened out of the blue i.e. with no work done to vehicle prior ? Anyone been under the hood doing regular maintenance work , like topping up fluids etc. ? Just checking that elect connections were not accidently disturbed.
If have scanner, check to see if there are any DTC's recorded.
Solution may be as simple as increasing engine RPM a tad closer to hi 600's -700.

 

Thank you very much for your answer! I Changed all the fluid in the car: Coolant,brake fluid,transmission fluid and engine oil. I doubt any of this work can cause vibration issues.I also changed spark plugs according to oem specs, I changed OEM battery for more stronger 72Ah AGM battery. Wonder if these can mess up electronics in my car.

 

- Spark plugs OEM quality from dealership or reputable auto parts store and not possibly cheaper knock-offs from Amazon or Ebay ? Knock-off plug(s) are known for causing misfirings & etc to name one most frequently observed.
- Presume you're aware that vehicle alternator w/factory settings is not able to charge AGM battery fully. Believe AGM battery needs 14.2 + volts to fully charge which stock alternator is not able to do. Check threads in this forum and others on the subject and the solutions to correct.. I have came across them but cannot recall from which forum. Mentioning this that by chance vibrations was related to a electrical induced fault.

 

Interesting.
My 2017 (75 K) also has a slight vibration stopped, in D, foot on brake. If I slightly release the brake the vibration largely disappears. This car has always exhibited this in my 3 years of ownership. Has not changed.
I think this is normal for a four cylinder engine even with a balance shaft.

 

Sorry, but I disagree. The sole purpose of a balance shaft is to counter secondary imbalances from the reciprocating movement of pistons moving up and down, in this case an inline 4 engine. Vibration ( or shuddering ) felt at idle is not normal, since the very presence of the balance shaft is there to negate said vibration regardless of what engine RPM is.
In general inline 4 of 2,0 liter and up needs a balance shaft as vibrations from secondary imbalances correspondingly increase. While engine below the 2.0 liter, vibrations are adequately managed/masked by engine mounts and such.

 

An update from OP will be much appreciated if a solution had been arrived at. It'll help others who may encounter similar situations w/their vehicles.

If condition i.e. vibrations had disappeared as they had mysteriously appeared, the explanation could be that the vehicle's engine ECU needed a couple of drive cycles ( or 50 -100 miles driven) to reset parameters ( idling RPM among them ) to where they were prior to your battery change-out. Hoping that is true in your case.
As an example, my '00 Acura RL needed the rad fan to come on twice after battery is disconnected to restore prior idling settings. My '05 4Runner needed 2 drive cycles after a throttle body cleaning for idling RPMs to drop back down to 650. I have not had to change out my OEM battery yet in my '16 NX. However, I'm a believer that anytime a battery chang-out is necessary in today's vehicles w/very complicated electronics/multiple ECUs, its prudent to hook up another 12V source to the vehicle's + & - connecting cables to ensure existing parameters are preserved.