Overheating - unknown coolant loss - tick tick tick - hard starting

[Greg_Sian]

My VT V6 overheats to hot then goes back down almost straight away, it has the tick tick tick lifter noise at start up for about a minute then goes away, although i changed oil and used lifter free it returned after 2 months... also hard to start both first thing and 20 or more minutes after stopping.

I have in last 6 months changed new radiator, cap, water pump, thermstat, top bottom hoses, bled system. signs of leakage from heater tap but checked when running and not dripping out or anything. Oil is clear on dipstick and under cap, trans fluid is also clear of water.

[sedgewik]

maybe something to do with the guage (sensor) had a 08 colorado it started tiking a couple of months after first service from holden (8 months old) 5000k maybe something to do with different oil not quit sure

[sedgewik]

get radiator place to do pressure test if they cant find anything blown gasket cracked head? maybe your starter motor has just about had the dic

[Jesterarts]

Overheating:
That sounds like a air bubble trapped in the coolant system. Had essentially the same symptoms in a VX and I just needed to bleed the system correctly.

Ticking:
One of the lifters might simply need replacing, they wear out and beyond that point there is no real bandaid solution. Have you worked out which bank it's on?
Is you are having issues starting it, the ticking could also be starter motor related.

Coolant loss:
This would directly be related to the temp issues. Is there a smell of coolant in the cabin? How much coolant are you losing exactly?

[Junny]

does the ticking get faster?

[Greg_Sian]

Replaced heater tap today as it showed signs of leakage.. after taking off engine cover to bleed radiator i found coolant leakage from torx bolt on top of manifold? looking at engine its on right side under 2nd injector?

Ticking is steady noise but goes after about 1-2 minutes, but last time it lasted 5mins.