jdavis500

For the last 4 weeks I have experienced a crazy whirring sound that has gotten progressively louder. The sound was present about 95% of the time, sometimes varied in tone, rhythmic, independent of engine speed or brakes, occurs at idle or under power, nothing I did would change the sound. When I turned the engine off, it would continue for about 0.5-1.0 second after the engine stops. I couldn't localize the sound, but it could only be heard inside the cabin. Not from the speakers. I finally got a chance to take it to the dealer. They confirmed the details of the sound and after some checking found a bulletin for a fuel pump electronic update. The fuel pump is located under the rear driver side seat. They had seen the problem very infrequently with the RCF, but had never seen it with a GSF yet. They are updating the car at the moment, but seemed very confident that the update will increase the fuel pump pressure, eliminating the sound and also improving responsiveness when accelerating. I searched and searched and couldn't find anything on this, so I thought I would post for others to reference.

yardie876

Uh oh... I think you're the first GSF owner to experience the fuel pump issue. Head on over to the RCF forum and you'll see the issue wasn't as "infrequent" as the dealer said. There were MANY complaints and some owners that went through up to three fuel pumps trying to remedy the whirring until the update was rolled out. The software update seems to have taken care of the issue though so you should be good to go.

IsfClyde

This is an old problem. There was a previous thread about this. I got mine done at 2k miles

flowrider

iTrader: (9)

Here's a couple of threads form the RCF forum:

https://www.clublexus.com/forums/rc-...fuel-pump.html

https://www.clublexus.com/forums/rc-...600-miles.html

and one from this forum:

https://www.clublexus.com/forums/gs-...ump-issue.html

Lou

jdavis500

Thank you all. The update seems to have cured the issue. Hopefully, it will stay that way.

Gomz91

I had this happened to me as well and i figured it was the fuel pump . Very helpfull post

jdavis500

Glad it helped. Apparently, a sound of this nature is referred to as a "drone".

ssmoked

Just curious, for the owners with the fuel pump issue, do you use Shell gasoline and drive on eco mode?

flowrider

iTrader: (9)

^^^^https://www.clublexus.com/forums/rc-...el-pump-6.html

Lou

jdavis500

I rarely use Shell and never use eco mode. I always use mid grade instead of premium fuel and often use Sport S mode.

tq745

Why mid grade instead of premium?

Gomz91

i use chevron 91

jdavis500

My understanding is that the only benefit of the higher grade is engine performance as long as you don't have knocking. Knocking represents preignition in the cylinder in this case from lower octane fuel which ignites quicker. Modern engines have knock sensors that adjust engine timing to prevent this from happening. I felt that mid-grade was a good compromise considering the cost. This car is fast enough that I am not worried about a fractional decrease in performance. The lower octane will not result in any other engine problems. There is no difference in how clean it keeps your engine. I would be interested in opposing views.

This is from the manual:

GS350/GS F
Select premium unleaded gasoline with an octane rating of 91 (Research
Octane Number 96) or higher required for optimum engine performance.
If 91 octane cannot be obtained, you may use unleaded gasoline with an
octane rating as low as 87 (Research Octane Number 91). Use of unleaded
gasoline with an octane rating lower than 91 may result in engine knocking
and significantly reduced performance. Persistent knocking can lead to
engine damage and should be corrected by refueling with higher octane
unleaded gasoline.

flowrider

iTrader: (9)

^^^^To each his own I guess. Why buy and pay for a high performance vehicle and then not put in the recommended fuel? I wont even use a fuel that is not designated as Top Tier. Wish they offered 93 octane in the west like they do in the east. Over time using a lower octane fuel than recommended may or may not have a detrimental effect on the engine. If that's a chance you're willing to take, good luck to you.

Lou

lobuxracer

iTrader: (2)

In my Supra it meant getting 13 mpg vs. 18 mpg. It was cheaper to buy 4 gallons of 100 octane unleaded race gas with every fill (additional 12 gallons) despite the race gas being 3x the price because I got 5 more mpg with the race gas mix. On my spreadsheet it was very clear that having the right octane saved me a lot of money per mile.