Car over heated

[Tnovo22]

So bit of a situation. I have a 2008 ve commodore, driving on the highway the other day car over heated. Waited for it to cool down, chucked some water in her and she was alright took her straight to the mechanic he did PH test for it and instead of it changing colour to determine what it was it was sucking up water instead. But he reckons cracked head. Been putting water in her the past few days as I got no other way to work. But checked oil not milky, exhaust isn’t white smoke. Any suggestions on what it could be would like a couple of opinions. Cheers

 

[hademall]

Thermostat? Assuming you’ve done all the obvious checks.

 

[greenacc]

You need to get a bit more technical about what you have done so far. If you just chucked a watering can into it on the side of the road then it would have an air lock in it. Maybe that's why it's still drinking water?
Did you bleed the air out? Have you checked the front and back and underneath the engine for leaking coolant? Same for the radiator? Also feel the carpet in the front seats is it wet?
Does it still drive smoothly or is it rough and lost power?
They can leak coolant in a few different places.

 

[Tnovo22]

Thermostat? Assuming you’ve done all the obvious checks.

That was my thought, mechanic said probably not… that’s why needing a second opinion

 

[Tnovo22]

You need to get a bit more technical about what you have done so far. If you just chucked a watering can into it on the side of the road then it would have an air lock in it. Maybe that's why it's still drinking water?
Did you bleed the air out? Have you checked the front and back and underneath the engine for leaking coolant? Same for the radiator? Also feel the carpet in the front seats is it wet?
Does it still drive smoothly or is it rough and lost power?
They can leak coolant in a few different places.

You need to get a bit more technical about what you have done so far. If you just chucked a watering can into it on the side of the road then it would have an air lock in it. Maybe that's why it's still drinking water?
Did you bleed the air out? Have you checked the front and back and underneath the engine for leaking coolant? Same for the radiator? Also feel the carpet in the front seats is it wet?
Does it still drive smoothly or is it rough and lost power?
They can leak coolant in a few different places.

Checked it all, did pressure test and got it serviced to be on the safe side too. That’s why I’m so confused

 

[Mickcc]

the story so far you have had an over heated Engine
managed to cool it down hoping not to cause any other issues
and now you need to find a leak in the cooling system
you can not find it but is the water still going missing how much or is it all good for now

 

[Tnovo22]

the story so far you have had an over heated Engine
managed to cool it down hoping not to cause any other issues
and now you need to find a leak in the cooling system
you can not find it but is the water still going missing how much or is it all good for now

Haven’t driven it over the week except moving it into the drive way to wash it. Water was full gone down a bit but not much.

 

[greenacc]

Checked it all, did pressure test and got it serviced to be on the safe side too. That’s why I’m so confused

At this stage you can't rely on anything the mechanic said. If they can't find it they have obviously missed something, don't know what they're doing, rushed it or the fault wasn't there at the time they worked on it.
So check everything, again, until you find it. What radiator cap is on it and where did you buy it?

 

[Tnovo22]

At this stage you can't rely on anything the mechanic said. If they can't find it they have obviously missed something, don't know what they're doing, rushed it or the fault wasn't there at the time they worked on it.
So check everything, again, until you find it. What radiator cap is on it and where did you buy it?

Yep will do that thanks mate, also car wouldn’t start yesterday battery was low. Started this morning but struggled a bit and small ticking noise from front of car

 

[Fu Manchu]

Regulars are going to roll their styles here but I see an easy fix and cause.

The caps become faulty. They can let coolant out and not back in. That can make the reservoir over flow very slowly.

The coolant filler pipe can get pretty yuck and not seal well where the cap fits. Then air gets in and that’s not great.

You constantly filling it up isn’t replacing leaked coolant. It’s replacing air in the system.

This can all be sorted by you with a $25 bleed bucket off eBay, a new genuine cap and some effort to clean the filler cap seat. Maybe some coolant and distilled water.

I think your car will be just fine after that and your worries disappear.

So, fill the reservoir with premix red coolant.
Then clean the seat/sealing surfaces of the filler neck.

Pinch off the hose to the reservoir by folding it and using a cable tie to hold it.

Fit the bleed bucket to the filler hole.

Poor in the red coolant and fill the bucket a bit.

Run the car. If someone can help with a bit of throttle every now and then, it’s handy.

It will take around 2 or 3 thermostat opening cycles before all the air is out.
(There can be litres of air trapped.)
Lots of fine bubbles and the odd big one come through. When the thermostat comes on, it’s going to bubble aggressively and the level drop so be ready to top up. You don’t want that to empty. You’ll need a few litres on hand.

Repeat the process.

Then cap the bucket.
Then remove it.
New genuine cap on.
Release the reservoir tube by cutting the cable tie.
Rinse the area down with fresh water.


It would be highly unlikely you have a major issue.


*If you still have the added water in there, I’d be dropping all the coolant and filling with fresh red coolant and then going through the above process. There’s a drain screw on the bottom of the radiator or you can release the lower hose.

Follow this guide
https://forums.justcommodores.com.au/threads/vz-ve-vf-alloytec-cooling-system-repairs.279976/

Other checks will be making sure your cooling fans are coming on. Inspecting around the water pump for dry pink crusty residue and also around where the coolant filler pipe goes into the engine at each end. It has a crap o-ring that lets go.

Few work shops know these cooling systems well enough now and generally do a poor fill and bleed regime.