High pitch whine noise from LH engine side

[Maxz]

Hi, uncovering new things daily since my supposed dead Battery.

Before I book the car in, want to check if this is normal.

After starting the main ignition mode, the engine runs for a few minutes and then stops. Does everyone else have this high pitch electrical whining noise coming from the LH middle/rear side of their engine? If not, will be changing my Battery assessment on Friday to a proper electrical review! Thanks all!

 

 

[Notamech]

Yes im pretty sure thats normal. I am not sure what it is exactly but suspect its the inverter pump running. I remember hearing this noise when the car is on but the engine has stopped. But might be worth asking when you visit lexus next just so all of us know what it is.

[Maxz]

1 hour ago, Notamech said:

Yes im pretty sure thats normal. I am not sure what it is exactly but suspect its the inverter pump running. I remember hearing this noise when the car is on but the engine has stopped. But might be worth asking when you visit lexus next just so all of us know what it is.

Thanks Notamech, appreciate the feedback, been filling up the forum with the questions recently but guess coming up to 10 years old, start to be concerned about the Gremlins coming alive.

I see similar chatter on the Prius forums in regards to once the engine fires, the throttle body motor becomes active and has a 12v feed to it. It's possible I only noticed it now given the checks I am making following my Battery issue, with my head deep in the engine bay looking around. Image of the part below, I may try disconnecting it to see if the hum stops to narrow it down (then reset any DTC codes that generate after).

It's reassuring to know you have the same high pitched electrical hum also, for now I will strike this one off the concern list and as you mention ask next time the service is due in August.

 

[IS300FSPORT]

++ I have a similiar sound rest your mind it's not a problem.

Maybe not as loud as yours I think your recording is close up hence why it's audible in the video.

When in EV mode the inverter is still circulating coolant it's an electric pump sound, that pump you can't see it's under the reservoir bottle. Keep in mind it's still charging the high voltage Battery instead of an engine sound its the equivalent EV motor. Just double check you have enough coolant if it's low could explain why the pumps working harder in theory the coolant shouldn't need topping up as its sealed. There are reports of water pump leaking look for a pink crusty powder near the aux belt the water pump is mounted behind the belt.

Your image above is the throttle body, subject to your mileage the throttle plate could benefit a clean but that's unlikely to make a sound. To get to that it's just a 10mm spanner follow the air filter box remove the rubber pipe & you will find the throttle body.

[Maxz]

1 hour ago, IS300FSPORT said:

++ I have a similiar sound rest your mind it's not a problem.

Maybe not as loud as yours I think your recording is close up hence why it's audible in the video.

When in EV mode the inverter is still circulating coolant it's an electric pump sound, that pump you can't see it's under the reservoir bottle. Keep in mind it's still charging the high voltage battery instead of an engine sound its the equivalent EV motor. Just double check you have enough coolant if it's low could explain why the pumps working harder in theory the coolant shouldn't need topping up as its sealed. There are reports of water pump leaking look for a pink crusty powder near the aux belt the water pump is mounted behind the belt.

Your image above is the throttle body, subject to your mileage the throttle plate could benefit a clean but that's unlikely to make a sound. To get to that it's just a 10mm spanner follow the air filter box remove the rubber pipe & you will find the throttle body.

Al, you are my hero for today! Per photo a clear dose of pink crust and when I parked the car flat at street level off my sloped drive, the coolant is in fact on low.

So you rightly state the motor is overworking and then that could also result in more draw on the 12v hence I went flat eventually.

Car has not quite hit the 10 year mark yet, so a claim on the Relax warranty for a new water pump should get this sorted. Thanks to all who have recently fed back on my posts, investigation over 👍

[IS300FSPORT]

Nice one nothing like abit of Internet Diagnostics (guesswork) haha

Out of interest what mileage has yours done? 

You probably already know this but as a precaustion just to be on the safe side avoid driving it unless necessary you may run into overheating & other problems, unless you can source abit of coolant temporarily to top it up.

[Notamech]

1 hour ago, Maxz said:

Al, you are my hero for today! Per photo a clear dose of pink crust and when I parked the car flat at street level off my sloped drive, the coolant is in fact on low.

So you rightly state the motor is overworking and then that could also result in more draw on the 12v hence I went flat eventually.

Car has not quite hit the 10 year mark yet, so a claim on the Relax warranty for a new water pump should get this sorted. Thanks to all who have recently fed back on my posts, investigation over 👍

Just so you know. The inverter coolant and engine coolant have completely different water circuits. The pump driven by the belt is the engine coolant pump you check the level of engine coolant by looking at the reservoir bottle on the front above the radiator(red in pic below).

The pump making noise from your original post is the inverter coolant pump. This is a plastic electric pump not driven by the belt and is meant to cool the inverter. The level of this coolant can be checked looking at the bottle near the throttle body (blue)

So if your engine coolant water pump is leaking that won't reduce the inverter coolant. Also that wont impact draw from the 12v Battery as nothing critical runs off the 12v Battery. Its only function is to start the car and power the alarm, security system, lights etc.

BTW that noise from your original post may not necessarily be the inverter coolant pump and could also be the high pressure fuel pump (for direct injection) building pressure.

Anyway good that you caught your warepump leaking. Get it replaced under relax.

[Maxz]

1 hour ago, Notamech said:

Just so you know. The inverter coolant and engine coolant have completely different water circuits. The pump driven by the belt is the engine coolant pump you check the level of engine coolant by looking at the reservoir bottle on the front above the radiator(red in pic below).

The pump making noise from your original post is the inverter coolant pump. This is a plastic electric pump not driven by the belt and is meant to cool the inverter. The level of this coolant can be checked looking at the bottle near the throttle body (blue)

So if your engine coolant water pump is leaking that won't reduce the inverter coolant. Also that wont impact draw from the 12v battery as nothing critical runs off the 12v battery. Its only function is to start the car and power the alarm, security system, lights etc.

BTW that noise from your original post may not necessarily be the inverter coolant pump and could also be the high pressure fuel pump (for direct injection) building pressure.

Anyway good that you caught your warepump leaking. Get it replaced under relax.

Good point, I think I have mis-linked the two, and the noise is normal, but good through all your tips actually found a/the real problem! 

[Maxz]

Just to update, with the car started and the engine stopped after it's initial run, I disconnected the plug from the Throttle Body and the noise stopped, so this is the source. Appreciate this is considered normal (and probably just never noticed before as I typically only pop the hood when the engine is off). Please note only do this if you have an OBD tool to reset the DTC code and clear the orange engine warning light from the dash.

Car booked in for next Friday for the water pump investigation and hopefully replacement before the car reaches 10 years and Relax is up (well it is only just turning 9 so next year). Seems regardless of miles (only 39k) at the very least the pump seal has perished. Possibly the number 1 area to monitor for any of those with an aging IS, plus 12v Battery charge and voltage level (easily done by holding the Menu button + 3 clicks to sidelight to bring up the Vehicle Signal diagnostic menu). If the voltage in Accessory mode is at least 12v after fully charging the Battery, seems to be an indicator that you won't get stuck with the Hybrid System refusing to boot.

[Notamech]

The 2013 2014 models are notorious for failing water pumps. Mine failed in the centre at the bearing. I have heard of a few others failing at the bearing as well.

Lexus later had a new part number for the stretch belt. So one hypothesis is that the older belt was causing the bearings to wear prematurely causing leaks.

[Maxz]

On 6/12/2024 at 3:37 PM, Notamech said:

The 2013 2014 models are notorious for failing water pumps. Mine failed in the centre at the bearing. I have heard of a few others failing at the bearing as well.

Lexus later had a new part number for the stretch belt. So one hypothesis is that the older belt was causing the bearings to wear prematurely causing leaks.

Yeah mine is really strange, seems to be leaking through the thread of the lower LH nut/bolt.  I am not touching it or investigating any further so it is obvious to the Lexus technician where the leak and therefore problem is. Hopefully they replace the whole pump and not just the seal otherwise when the bearing goes will need to replace it then anyway.

[Maxz]

Just to update leaky water pump (see image) replaced under Relax warranty and throttle body electrical noise/buzz expected behaviour.