JREAL

My car rpms jump when the car idles and its trippy. Im not sure if this is a major must fix or if its just because of its age. Its a 2000 ls 400 and I have no warranty.

SpencerT

You have the newest car in this forum O.o

PureDrifter

iTrader: (10)

It's still 13 years old...

Op you probably have a vacuum leak.

LScowboyLS

vacuum leak, engine coolant temperature sensor or ECU capacitors are the most likely

JREAL

Where is the engine coolant switch

JREAL

Whats a good price for these types of repairs

LScowboyLS

engine coolant temperature switch is on top of the engine (green sensor in pic below), around $50 at the dealership and less than 1 hour labor to install

Lavrishevo

iTrader: (1)

The sensors are in the same place on the 98 - 2000 model? That pic is from a 95 or similar right?

LScowboyLS

Yes & Yes

PureDrifter

iTrader: (10)

not exactly, similar location, but up close against the throttle body since it's mounting forwards on a '98-00.

johnny123

The posted image is somewhat misleading: there are two "engine coolant temperature switches" on these engines, and none are in that image. The two that are there are "Engine coolant temperature SENSOR" and another one with one wire I believe is correctly described as "the coolant temperature gauge sensor" (which is the gauge we see on our display).

I only came upon this posting because I am looking for this elusive "engine coolant temperature switch" of which there should be two, one mounted on the bottom of the radiator, and the other, somewhere else... which all influences the electric cooling fans, which in my case do not work right now, even though they are ok... apparently those switches are not sending a signal to turn on the fans.

Sorry that this does not answer the OP question, but if I had to venture a guess, for a 13 yr old LS, I would first check the ICV and then the caps on the ECM (or ECU - same thing).

LScowboyLS

there are two switches that affect the fan(s) - the engine coolant temperature switch in the bottom left corner of the radiator and the A/C pressure switch, located on top of the A/C dryer, which is physically quite near the temperature switch.

there is also a cooling fan relay that needs to be working right for the fan to come on

this table may be helpful, keep in mind that "A/C switch" in this table refers to pushbutton switch inside car on climate control panel



also, you can test the motor itself easily, hook up in series with an ammeter, directly to battery, motor should come on at the HIGH speed and pull between 4.2 - 4.4 amps