Due to a hairline crack on the plastic part of the rad (at the top near the filler cap) I had a local garage replace the radiator. Since collecting the car there is a noticeable sound coming from under the dash that sounds like water sloshing around. I am aware that this is the heater matrix, but wonder why its doing it. The water in the header tank hasn't moved, is it an airlock in the matrix and if so how best to clear it?

Sounds like you've got an airlock, the coolant system needs bleeding. Best way is to drain it start again but fill it through the hose that runs to the turbo rather than directly into the header tank. Do a search and you'll find plenty of tips

Cheers fella

As above, there is no true method of bleeding it, so start again.

THIS time, ensure the heater is set to HOT throughout.

Took the car back to the mechanic that changed the rad. He said it was better but he still couldn't bleed 100% of the air out, but couldn't understand why as he had used a vac pump, and looked on forums for answers.

Got the car home and noticed steam coming from under the bonnet. Opened it up and looked and the new rad is dripping water from the plastic cylindrical shaped part underneath the radiator cap and mount.

Phoned the supplier that I purchased the rad from and they want me to buy a new rad, get that fitted and send the faulty one back and they will pressure test it and refund me if it is found to be faulty. Not too happy with that to be honest.

Which part of my post where I said categorically that you CAN'T BLEED A SCOOB COOLING SYSTEM did you fail to understand?

So you continued to drive it airlocked, overheated it and are now moaning about a cracked rad? You couldn't make it up....

I took the car back to the mechanic as he is the person that fitted the rad!
NO THE CAR DID NOT OVERHEAT. The temp gauge remained at the level it has always ran at, the heating system worked as normal.

I know, and the mechanic knows that the system should self bleed. The fact that it hadn't, and couldn't even with the help of a vac kind of points to the fact that air was getting into the system.

And you said and I quote "there is no true method of bleeding it", not "YOU CAN'T BLEED A SCOOB COOLING SYSTEM"

Thank you for your condesending post.

The system certainly does not self bleed mate.

What an utter load of b*****s!
So all scoobs are air locked

Best way is to simply pop the little pipe off of the top left of the rad then fill header until water runs from the pipe, Take it for a run, let it cool then top up if needed,
job done

Thanks for the advice and lack of presumptuousness

One thing I didn't mention in my opening post though, is that the car is a 2003 my, so the rad is different to earlier models in the fact that it has a seperate header tank but also has a filler cap on top of the rad as well.
Would the method you mention still be relevant?

The last time I had a coolant issue was down to the top hose to rad splitting, so I changed the pipe and topped up the rad and ran it with the cap off until it was warmed up. Didn't have any issues with airlocks.

No, all Scoobs aren't airlocked, they have to be filled properly to avoid it

WRXRowdy: can't stand the heat, stay out of the kitchen mate.

Oh, and find a mechanic who KNOWS Scoobs, eh?

Just curious............does it sound like a little waterfall behind the passenger footwell / glove box ?

Shaun

I recently had to replace my thermostat, once all was back together I took the cap off and filled whilst the car was running with the heater on max... Just keep topping it up until it stops kicking out bubbles.. The filler tank is the highest part of the system.... The air will rise..

alcazar your full of pearls of wisdom, got NOTHING constructive to say, then stay out the thread mate.
Yes Shaun, thats exactly what it sounds like.

I gave you something constructive: you ignored it. Your bad.

No, you really didn't.
You gave me three replies. The first was basically stating what had already been said in a previous response by another user, quote "as above", and then went on to assume something that you were incorrect in assuming.
The second you accuse me of ignoring something that you misquoted yourself as saying, when it wasn't even me that carried out the work on the car, and then assume that I have carried on using the car and that I have overheated the car. Again, wrong on both counts.
And then a post saying "if you can't stand the heat get out of the kitchen".Very constructive, how old are you, three?
So I can't post on my own thread now then?
What the **** are you, forum police?

https://www.scoobynet.com/scoobynet-...ter-sound.html

Have a search on here for similar threads

Shaun

What part of "there is no true method of bleeding" aren't you getting?

I DON'T CARE what you've found on other forums, I'm telling you: Impreza cooling systems can't be bled, so drain and start again, and do it properly

Ah, the good old Scooby water feature.
You are not alone!

MY POST FROM AN OLD THREAD:

Hope this helps, it you are not prepared to do all this don't bother starting...........

If its not been done properly each time it will airlock each time .

After experiencing many airlocks in my own impreza and a legacy I had previously,This is the way I do it , other may do it differently but I find this works for me every time.

-Get the front of the car as high as possible on axle stands

-Get a small Funnel that will fit into the turbo coolant hose coming from the header tank (largest hose coming off the header tank going to the turbo).Fill the system through this hose while having the cap off the header tank.

-Once filled (will take about 7 litres roughly) reconnect the hose to the header tank,Leave the cap off the tank, start the engine and turn the temperature control on the dash to fully hot and fan speed to full.

- Get someone to hold the rpm at about 2000rpm , until the temp starts to come up about 1/4 of the dash gauge.Keep topping up the header tank as the level will drop.This will take a bit of time as the heating is on full blast it will take heat away from the engine.

- As the gauge starts to read half-ish,Turn the heating fan speed to half and raise the rpm to 3000rpm, while continuously checking the level in the header tank.Top up as necessary.

-Once the thermostat opens and the bottom rad hose starts to heat up , put the cap on the header tank, check that you have heat in the car (you should at this point) once you are happy with that,turn the heating off and drop the revs.

-Let the car idle for about 5 mins, checking for leaks and check the level of the expansion bottle it should be at the full mark if not add some coolant until it is. Once the rad hoses are pressuized the job is done.

-Take the car off the axle stands

As I said others may do it differently including Subaru specialists, but I find this works everytime.

Hope this gets you sorted

Barry

Where have I argued that there is a method of bleeding?????

Where did you get the idea that I have found anything to say otherwise on another forum?

I said the mechanic has looked on forums to work out what is going on.

New rad has arrived so will pass on the info to the mechanic, thanks Baz .

No bother mate