Rough idle on 14 LX

[risban]

Hi all. My 14 LX with 73k has developed an intermittent rough idle. It will shudder a bit when its idling around 750rpm. I also have experienced the RPMs bouncing between 400-1000.

My fuel mileage has also dropped by 1.5mpg in the last month. I recently installed OEM sized Nitto Terra Grappler G2s so I am not sure if that has contributed to the mpg drop.

It's currently at the dealer and the tech does not believe the idle issue is related to the fuel pump or idler pulley. He is recommending a BG fuel induction cleaning service. Anyone have an opinion on it's effectiveness?

Thank you.

 

[posgu]

When did you last change your spark plugs?

 

[04UZJ100]

When did you last change your spark plugs?

It’s a 14 with 70k miles. Plugs are rated for 120k.

 

[risban]

When did you last change your spark plugs?

Plugs haven't been done yet.

 

[32cls6speedmt]

How much are they quoting on the bg fuel induction cleaning?

have you been using top tier gasoline?
my 2013 lx was serviced at a lexus dealership that used bg 44k file treatment every 5,000 miles.

it is works well based on my research. It is about 25 dollars a can and carried by Amazon.

 

[pwag]

Ensure all blades on your radiator fan are intact. I had one partially damaged, took a while for tech to figure out. Caused rough idle/shake.

 

[risban]

Ensure all blades on your radiator fan are intact. I had one partially damaged, took a while for tech to figure out. Caused rough idle/shake.

Thanks for the reply. Will have them check on that.

 

[risban]

How much are they quoting on the bg fuel induction cleaning?

have you been using top tier gasoline?
my 2013 lx was serviced at a lexus dealership that used bg 44k file treatment every 5,000 miles.

it is works well based on my research. It is about 25 dollars a can and carried by Amazon.

I haven't gotten the quote since they were closed over the weekend.

The BG fuel treatment was done at 61k in September 2019 and also in January 2019 by a previous dealer.

I used to run Costco premium but switched to Chevron premium 6 months ago.

 

[radman]

I used to run Costco premium but switched to Chevron premium 6 months ago.

what's wrong with Costco premium?

 

[risban]

what's wrong with Costco premium?

I was driving out of the way for Costco fill-ups.