RX300 1999 AWD

Feels like the car wants to jump in at stop/brake. The rpm needle jumps up and down a little bit, while putting it on neutral at stop puts the idling stable. What could it be ?

Thanks,
Mike

 

Don't know what you mean by jump in. Idle is not stable when in drive? Does the car try to jump forward or just the idle is not stable? It would be much easier to help if you posted a video (make it safely of course).

 

Brake Booster possibly leaking ?

 

I too would say we need some clarity. No bonus points for being so brief that the message is not clear for the audience.

The engine load changes when the shifter is in drive vs N or Park and it is expected that the rpm would change. If is is spiking way up then we need further investigation.

If you have not serviced your IACV (search on this please) in about 60K miles, then I would suggest clean it out. This device modulates the idle based on the command form the ECU.

Salim

 

I got this morning code P0304 but I am not sure if this is related to this issue. Check engine light comes and go away.
I swap the ignition coil located engine at front center and front driver, reset the code, remove the battery cable connection for few minutes.
Reconnect battery and test drive, same P0304 comes back with check engine light turn on then off. Next, I gonna swap spark plugs.

RX1999 185Kmiles AWD

 

Thanks. I will try to clean the IACV.

 

t


I found a crack on spark plug at#4. I will place #6 plug to #4 and buy new one to place at #6.

 

Oh wow.
Can really see the crack in it.
Is that an oem plug, what's the brand and part# on it?

Your pic

 

spark plug is denso. it was bought at toyota dealership parts department. Changed at 140Kmiles (now is 185Kmiles)

 

problem is at stop feels (car wants to jump in). shifter at drive. brake pedal pressed
(not sure why i could not attanched the video clip)

 

Issue was fixed after changing the plug. car feels different before changing the plug, and now feels normal

 

Parts bought from Lexus have implied warranty. Check with them as there is milage or time.

I can not understand "jump in". Does that mean "stall' as in engine shutdown.
Salim

 

IMG_4963.mov is the video of the rpm meter when I have the issue, I mean it feels the car want to moved forward. It feels different before the fixed.
IMG_5015.mov is the video after the spark plug was replaced.

 

To me it looks like low idle issue. Time to clean up the IACV or trace a vacuum leak. Good idle is 550-750 when engine is warmed up.

Salim

 

At only 45k miles on oem plugs it's surprising to see this.
I can only think about "what if" that ceramic broke off and fell in the engine.
Engine rebuild time?

Your plug