janmy7

Hi,
My GS350's RPM meter won't drop if I press break.
It will increase to 2000 then drop back under 1000 rpm suddently.
This is only happened in the early morning(after a night cold down) when I start my car. After minutes ride. It won't happen again.
I notice this issue after I sent the car for a lately recalled by Lexus.
Is it normal? Do you have the same issue with your GS350?

alchemist

iTrader: (1)

hmmm normally rpms will rise when you hit the brake because the brake booster uses vaccum to operate and this draw on the engine causes the rpms to rise, but by 1000 seems like a lot.

vladbph

If temp is lower than 39F then it is quite possible. It holds 1000rpm even with brake pedal pressed until engine warms up a little.... no worries

chuckGS350

Normal. When it's cold, just star uup, and pressing the brakes a bit hard.
Nothing to worry about.

KJSmitty

Did you guys read what he posted? RPM jumps up to 2000 when he hits the brakes...

OP - have it checked out. Vacuum brake booster or not the RPM should not jump up. If the engine is decelerating while braking it creates more vacuum with the throttle closed. I've never seen nor worked on a car that was designed to bump RPM up while braking... For the AC compressor operation yes, not to facilitate the brake booster (at least not 1000 RPM).

Now, obviously I am diagnosing your car from my iPad yet what I believe you are experiencing is a "high cold idle". The jump of RPM to 2000 or so is due to the car downshifting while you are braking. That is why you see it drop to 1000 once stopped etc.. High cold idle is a common item with the older 350s. Describe it to your tech/dealership.

Cheers

janmy7

Yes, You are right. I warm up my car in the cold NYC weather. (around 30F- 39F)
If it's in the warm weather, It won't happen. Do I need the dealer ship to check it? Or it's normal?

KJSmitty

If the high idle is only until it warms up a bit, say 2 minutes or so that's not bad but if more I find that excessive. I know my GS350 tends to idle high (1500-1700 rpm) for too long. I notice it the most when approaching a stop and like you the car does not idle down and wants to race forward at the stop. I don't consider that normal for a modern car with fuel injection. But like you mentioned only when pretty cold. I plan to inform my dealer when I take it in for the same recall notice.

Hard for me to say what yours is doing exactly but if like mine I would bring it to their attention the next time I was at the shop etc..

Cheers

janmy7

Yes yes. Corret. I think you explaint my issue more clear thand I did.