Massive overflow from coolant reservoir.

[Antsmash]

Hey guys,

I got my water pump replaced today because I was having some circulation issues.

Mechanics finished it up this afternoon and I drove it home in about 30min of peak hour traffic. Temp was at 1/3 whole way and I was quite happy.

I got home and sat in the driveway for a few min, just to make 100% everything was fine. After about 3min temp started to rise and I thought, "Oh god, here we go again." I then heard a gargling sound which sounded like it was from the heater core. I turned the car off straight away, got out, and there was a very large amount of coolant that came from car.

I searched where it had come from, the bottom rad hose was fine and was bone dry, so I came to the conclusion it must of come from the Overflow Tank. Checked the level and for some reason the tank is well over max reading, and it think it was before that too. Will this be the cause of the problem? And somehow since so much pressure was release it dumped what was about 4 litres of coolant on my drive. It popped the little hose out of the overflow neck too.

I just replaced the radiator cap about 3 weeks ago when troubleshooting. Do you think this could be faulty? Thanks.

[jas98]

Hey guys,

I got my water pump replaced today because I was having some circulation issues.

Mechanics finished it up this afternoon and I drove it home in about 30min of peak hour traffic. Temp was at 1/3 whole way and I was quite happy.

I got home and sat in the driveway for a few min, just to make 100% everything was fine. After about 3min temp started to rise and I thought, "Oh god, here we go again." I then heard a gargling sound which sounded like it was from the heater core. I turned the car off straight away, got out, and there was a very large amount of coolant that came from car.

I searched where it had come from, the bottom rad hose was fine and was bone dry, so I came to the conclusion it must of come from the Overflow Tank. Checked the level and for some reason the tank is well over max reading, and it think it was before that too. Will this be the cause of the problem? And somehow since so much pressure was release it dumped what was about 4 litres of coolant on my drive. It popped the little hose out of the overflow neck too.

I just replaced the radiator cap about 3 weeks ago when troubleshooting. Do you think this could be faulty? Thanks.

was the thermostate replaced? and bled the system properly? sounds like one of these would be causeing it

[Antsmash]

was the thermostate replaced? and bled the system properly? sounds like one of these would be causeing it

Thermostat was replaced. Do you think a possibility it didn't open and caused alot of pressure?

My main question was can a badly overfilled overflow bottle cause this?

[Dayvo]

Check that your fan is coming on . When you are driving air is forced theough the radiator and keeps everything cool so temp will be normal . When you are sitting in your driveway there is no air flow so temp rises .Also check radiator cap seal could be worn.

[Fletch_QLD]

I recently had this exact problem. Situation resolved by replacing radiator cap.

My thinking/logic is thus :

If the temperature remains normal when the engine is idling - (by which I mean idling after a good drive and operating temperature is reached) - then the cooling system is working correctly - ie, the thermostat, waterpump and cooling fans are working together and doing their job.

When you kill the engine, the thermostat, waterpump and cooling fans no longer factor in, there is no coolant flow. All the heat in the engine bay now causes the coolant temperature to rise. This is the point it is most likely to reach the highest temperature - and exceede the pressure limit of the radiator cap. By this I mean the actual limit, not the theoretical/stated limit.

This temperature rise, and corresponding increase in pressure would be exacerbated if there is inadequate coolant in the system - ie if the system is poorly bled.

A new radiator cap can be dodgy - when I had the problem a search of the boards found people who have had this same problem caused by new radiator caps. It's also about the cheapest possible part you could try replacing. There is talk in the forum of certain cheap brands of radiator cap being useless. I can't really comment on that - I just decided to go to holden and get a cap from them, and problem solved...

[Antsmash]

Thanks for the replies!

When it overflowed it was running in the garage. I re-filled and drove to supermarket last night. A little overflowed onto ground while it was parked but not much. Have been on three drives today, two of them were mostly in start stop traffic (Festivle on by my house) and was perfect 1/3 the whole way, sometimes at a dead stop for 3 ish min.

Guess I'll just have to see, and get the extra fluid out the overflow tank. It was a rushed job by mechanics on Friday afternoon, so there could of still be some air in system or something that cause massive overflow while idling after drive.

I'll make sure to go Holden Dealer next week and get a rad cap for piece of mind.

Thanks again.

[Antsmash]

Check that your fan is coming on . When you are driving air is forced theough the radiator and keeps everything cool so temp will be normal . When you are sitting in your driveway there is no air flow so temp rises .Also check radiator cap seal could be worn.

That's true, but I was sitting still for quite a bit in traffic. Perhaps it was because our driveway was on an incline.

[Fletch_QLD]

If the overflow is too full - it will self correct, by emptying on your garage...

[Antsmash]

If the overflow is too full - it will self correct, by emptying on your garage...

It took about 4 litres to fill at least though. While it was on. Wasn't a leak whilst it cooled down.

[SavVYute]

If the overflow is too full - it will self correct, by emptying on your garage...

+ 1 for that.

It just belched. Should feel better now.

[Antsmash]

+ 1 for that.

It just belched. Should feel better now.

Had night after overdosing on coolant ?