Cooling issue: Cracked head or Gaskets? Something else? Please help :(

[Nigel77]

Not impressed with the colour of your coolant, should be a nice bright green, nor the cruddy filler neck. Time for a flush and refill ?
Don't know about the position of 'stopper' or how you got something upside down. The cap should not come apart.

Edit …….. not 'green' coolant, red. I've got my cars mixed up.

The coolant colour did look odd when I first saw it. It's just how it looks against the cap. I grabbed a clean tissue and wiped some off and it was a perfectly clean red. No gunk or anything.

Sorry, regarding the "upside down" description. What I meant was if you are standing at the front of the car and look at the radiator cap, the writing would look upside down. If you screw the cap on another 180 degrees, it will look "upright" by orientation.

So what I was trying to say is that when I initially went to remove it the cap was not on as far as I managed to screw it on when I put it back. Don't know if this would make much difference as it was on quite tight regardless.

But that stopper thing I circled, suggests to me the cap is meant to be screwed on a fixed amount until it hits the stopper. Mine wasn't. And I can't get it to hit the stopper myself due to being weak as piss.

 

[krusing]

Small update:
Had a few minutes before I have to go out so just did my usual quick coolant check. My dipstick thing was pretty dry but fbefore I topped it up, I found the radiator cap.

https://imgur.com/a/zvSMPcz

It's not a genuine radiator cap according to my googling. Though, it seems it's acceptable as it's the same rating and from a reputable manufacturer (CPC). See Photo #1.

Photo #2 shows the level of coolant after opening up the radiator cap. Don't know if this is good or bad.

Photo #3 is after I had screwed the cap back on. Note the little stopper I've circled. Now, when I first undid the cap, the cap was in an upside down orientation. When I screwed it back on, it is in an upright orientation. I didn't know about the little stopper thing before, but given that the cap has ended up in a different orientation than before, I suspect it wasn't on all the way? Granted it's REALLY hard to screw on after a while. This is as far as I could manage to get it. I hope that's ok.

My OEM Radiator Cap failed not long ago, and ended up purchasing a CPC replacement, [from Mace Engineering]
I read somewhere, GM Used CPC Radiator Caps,
but relabeled them, and marked them up accordingly.

 

[syked]

Yes the cap should go all the way to the stopper otherwise it's not on properly. Maybe take it off again and lightly clean the filler neck with a small wire brush.

 

[MattSAU2XR8]

If the problem is a blown head gasket and it connects a coolant chamber to a combustion chamber then a 'TK head check' could detect it:

1. When engine is cold remove radiator cap and sit test canister, full of colour change indicator fluid in the spout.

2. Start engine and if the head is cracked exhaust gas bubbles will appear in the coolant and drain via the test chamber

3. And indicator fluid will change colour from blue to yellow...

https://www.2carpros.com/articles/head-gasket-blown-test

However if the head itself is cracked and coolant is leaking into the intake ports or oil for for example then this test would come back negative.

Other places coolant can go:

1. Loose hoses leaking externally

2. Radiator leak external

3. Radiator leak to auto transmission

4. Heater core to cabin (I wonder if this could end up draining to ground via the aircon drain pipe...)

5. Engine oil as per cracked head or gasket above

6. Combustion chamber via cracked head or gasket above

7. Exhaust port as via cracked head or gasket above

8. Welch plug in block leaking

9. Thermostat housing leaking

10. Water pump leaking

Could also consider either buying a UV light to look for leaks, or parking it over some clean newspaper and running it for a while...