G'day I drove my car today for the first time in a while without music on and I heard a 'slushing' sound from the engine. It sounded like it could either be fluid moving in the gearbox or coolant being forced around, cos as the revs increased the sound got louder. Has anyone else had this problem?

I think I know the noise you are refering too......it's not good news
If it's what i'm thinking of, its pockets of gas in the coolant and you can hear them passing through the heater core, at best it indicates a cooling system leak somewhere, and at worst it indicates a blown head gasket or cracked head.
I have one TR that i have just pulled apart to fix this problem. This car has a pin-holed welch plug and on cold starts I can hear the little bit of air that gets sucked in overnight passing through the heater when I first raise the revs.
I have another TR that will make the same noise after starting either hot or cold, this engine still runs fine but i suspect it has a blown head gasket or cracked head because i know it was overheated.
If your car is constantly making this noise and it raises with revs, then i would suspect a serious loss of compression from a cylinder to the cooling system, Fill the radiator with the car running, let it walm up with the radiator cap off and see if there is a constant bubbling or air pocket surge.
Normally it will do this a little bit to expell air when you first start the car but should settle down pretty quick it's when the radiator bubbles continue that you have a problem.
During this check try to keep the radiator filled to the brim so you can still see any fine bubbles. Rust on one spark plug tip will confirm which cylinder is leaking.

Thanks for that. :confused: Great hopefully it's just the gasket, I can do that myself.

I had a similar problem, major concern was needing a few litres a day to top up the radiator. Got a mechanic to have a look while I was getting pink slip and was told the intake manifold gasket was leaking.

I replaced that just recently and I think it is all sealed up well. Was very particular about cleaning all the surfaces well etc.

I still had a slushing sound afterwards and eventually found a small leak near one of the throttle valve hose connections.

One question though. Does it take long to get rid of the air gaps in the system? I am pretty sure I fixed the hose leak, but I check the radiator in the morning when cold and it generally needs a little bit more water, but less and less everytime it seems.

Should the air go pretty quickly?

when removing intake manifold you flushed the radiator right, then when you filled it back up you only filled the radiator, once you started the car the coolant/water would've filled the rest of the system as well (thermostat, around the cylinders, throttle body etc), thus after you drove it you'd have add some more water.

The leaked air would have sealed in and been burnt with the combustion process.

Has the slushing sounds since gone too?>

I checked the radiator this morning and I basically didnt have to add any water at all. Just a dribble to fill the neck of the tank.

I did take it for a small drive and there is very quiet slushing noise but only barely. I think there is still some air but as you said it must be slowly getting removed through whatever process.

I noticed the overflow bottle had filled up a little bit yesterday. I had it on the full line when cold, now at about half way, but not moving any further. I have a feeling the after a little bit of driving the small amount of remaining air is allowing pressure to build up and force some fluid out past the radiator cap.

I will keep an eye on it, wont be driving it too much until I can replace this darn O2 sensor.

After a week or two I still have the slushing sound in my Verada. I originally thought the car's poor running when hot was due to a dodgy O2 sensor, but today I confirmed that my O2 sensor was indeed functioning ok, as did every other sensor the ECU relies on. The radiator still seems full but I am thinking it might be just due to exhaust gasses filling it up.

So basically I think I have come to the conclusion there must be a small leak in one of the head gaskets. I am looking at getting a compression tester in the next few days to check the general condition of all the cylinders, but not sure if it would show up the small leak. I will wait and see.

If I have to change the head gaskets I will look at the valve seats, lash adjusters and anything I can think of.

After a week or two I still have the slushing sound in my Verada. I originally thought the car's poor running when hot was due to a dodgy O2 sensor, but today I confirmed that my O2 sensor was indeed functioning ok, as did every other sensor the ECU relies on. The radiator still seems full but I am thinking it might be just due to exhaust gasses filling it up.

So basically I think I have come to the conclusion there must be a small leak in one of the head gaskets. I am looking at getting a compression tester in the next few days to check the general condition of all the cylinders, but not sure if it would show up the small leak. I will wait and see.

If I have to change the head gaskets I will look at the valve seats, lash adjusters and anything I can think of.

also check the seal on the radiator cap

I replaced the radiator cap only a few months ago, so pretty sure that it is fine. Having said that I could possibly have a dud.

I have a compression tester now, so I am going to test that and see what eventuates. If that diesnt show much I will get the guys at the radiator shop to pressure test the bugger.