boris

As you can tell from the title I have this sound in my car. I always listen to music in my car and probably never had a chance to notice it. So I don't know for how long its been there. Now, what causes it, how can I fixe it? Any suggestion would be helpful.

Och

iTrader: (3)

Your water pump is going.

boris

So far mostly what I read was that there is either problem with heater lines being blocked or heater core. Any experience or suggestions? Water pump? Could you please elaborate, thanks.

Och

iTrader: (3)

Well tell a bit more about your car, year, mileage, maintenance, so we can help you better.

But yes, often water sound in the dashboard is caused by blocked heater core, but thats pretty much unheard of on LS400 with its aluminum engine block theres just no corrosion in the cooling system.

Make sure your coolant is at proper level, and make sure you're using Toyota red antifreeze, not the stuff from autozone. But like I said before, your water pump is most likely already on its way out, make sure you watch your temperature gauge closely.

boris

Here is a little background, the Lexus is 95 and it has about 123k. I ve noticed that heat is weak and it needs to be cranked up but often works fine. However definitely irregular. I hope this makes sense to someone in diagnosing the issue. Thanks

PureDrifter

iTrader: (10)

you have an air bubble in the heater core.

python

iTrader: (4)

its not the thermostat opening up?

fourthmeal

Boris,

the heater core takes engine heat out of the coolant and disperses that heat via the core fins to you in the cabin with a fan. The reason you aren't getting warm is that air is trapped in the heater core, like PD said. the gurgling sound is likely this air bubble (trapped at the top of the core, since air is lighter.) You need to flush the system, fill it with Toyota red coolant, and bleed the air out of it.

Och

iTrader: (3)

It could be air in the heater core, and in that case, here's what you do.

First of all, check if you have red coolant in the system. If it is red, then you don't need to flush. If it is green then you need to flush it.

Assuming it is red, go to autozone, buy a radiator funnel, they are like $3 a piece, and then stop at Toyota dealer and buy a gallon of coolant.

With the engine off, remove the cap from the reservoir and replace it with the funnel. Fill it with coolant just so that the coolant level is just above the bottom of the funnel. Start the engine, put the heat on full and fans on full, and let the engine run. As the engine warms up, you should start seeing air bubbles coming out of the funnel and coolant being sucked in. Keep adding coolant until the bubbles stop. Sometimes the procedure can take a while, raising engine RPMs helps bubbles come out faster. After there are no more bubbles, shut off your engine and let it cool. There will be some coolant in the funnel, dont worry about it, as the engine cools down its going to get sucked in. After the engine is cooled down, and all the coolant from the funnel it sucked in, remove it and close the cap.

Hopefully that will help. In my case, couple years ago it didn't help. Noise still persisted and a short while later car started running hot, and I had to replace the water pump.

python

iTrader: (4)

hmmm, i hear that noise all the time and have since ive owned the car and i have not had any problems with my heater not working. i assumed the noise was water rushing through the heater valve area. also i would like to know how ur water pump causes ur car to run hot? the only way ur water pump can make ur car run hot is if the impeller has disintegrated,the bearing can go out which will cause a wobble in the fan clutch(not applicable here). so like p/d said u may have an air bubble which these cars are famous for,but ur waterpump is not causing anyones car to over heat

fourthmeal

His car isn't overheating. Heater core air bubble, easy fix.