Interior fan blowing warm and trickling water sound

[dankernow]

Hi all,

In need of some advice before the winter sets in. I've  had four Toyota cars for the past 8 years and this is the first issue I've had with any of them. Last Saturday I purchased a avensis t180 with a full service history stamps but not done at Toyota. There is not many receipts for previous work done. 

So I'm experiencing Luke warm heat in the cabin with heater set to high and blower set at any speed. Trickling of water sound behind the dash with fan on or off. Coolant level is at the max level in the reservoir but at least one large hose is cold and feels empty when the engine is up to temp. 

I've ran the engine until at normal operating temp with the fan on full and the reservoir cap off. Squeezed all visible hoses and nothing has changed. Coolant level has remained the same with some escaping from the over flow pipe. I have a receipt for a water pump purchased but no proof of fitment and I don't know where its located to see if its been fitted 18 months ago.

So my question is,  do i take it to get a coolant change, thermostat/ water pump and hope this solves the issue? Or is it likely to be anything worse like a head gasket issue? There has been no over heating in the week I've owned it and no leaks or gunk in the oil cap.

I would appreciateyour advice please 

[Archie0979]

You could have air in the coolant system or you might have a blocked heating matrix.

[dankernow]

How do i diagnose those please? It's due a coolant change, so I thought if i get that done and a thermostat that would solve the air problem. I wouldn't know where to start with the heater matrix? Thanks 

[Archie0979]

Basically we had the same kind of issue on my partners car. Bleeding the air out can be straight forward. Normally it should manage to do it on its own and all that is required is to keep opening the header tank for a few days as the air should all feed back to there.  If not you could try while the car is running to disconnect the coolant return hose from the coolant tank while continuously filling up the tank not to allow it to empty and suck in more air then reconnect it when finished. It will soon become apart if there is air as it will bleed out the return hose. In our case this did not work and it was the heating matrix that was blocked. I can't give advice on how to fix this as I just got out local mechanic to do it. It was not expensive to get done.

[dankernow]

Thanks, I will try bleeding the air for a few days and see what happens.

[Archie0979]

I have recently had a similar issue on my Avensis. I have just bought it but the water pump had a leak and it dumped all the water as it was sitting 4 weeks before I bought it. I filled it up but for a few days I kept getting a gurgling/water swooshing sound behind the dash. A few days of continuously opening the header tank and topping it up solved the issue and now the air is all gone and I get no funny sounds.