TB42 intermittent overheating question

[markh5000]

Hi all, just wondering if anyone could shed some light on an intermittent overheating issue with my 89 GQ auto. I've only had it a couple of months so I'm not familiar with its quirks, but on its last trip the temp was fine for most of the outward trip (only about 15k) but then, after about 10k, climbed up past the 3/4 mark. On the return trip it did the same thing. What seemed odd is that it did it when i was only doing 60-70kmh, having come off the highway. I wasnt using the a/c and it wasnt a hot day. It normally runs just below 1/2

I have bought a new clutch fan, not yet installed it, but I am wondering if I'm on the right track. The gauge seems about right, coolant was bubbling into the overflow, and it sucked back up when it cooled. Not sure if the top hose was pressurised, will check it again this weekend. Cant see/hear any leaks, no cream under oil or radiator caps.

Any suggestions gratefully received!

Cheers,

Mark

[Bloodyaussie]

Mate I just pulled my radiator out and it was only 60% free of blockages through the fins... then there is the inside itself??

Also it is worth changing the thermostat and flushing with new coolant, none of which is hard and can be done in about an hour.

[markh5000]

Thanks BA.
Can you use a pressure cleaner on the radiator or is that a bit over the top? And re flushing with new coolant - is it simply a matter of draining the old and filling with new, or is there some sort of skill involved?

[Dales300exc]

You say it was bubbling into the overflow? It shouldnt bubble. Headgasket

[markh5000]

I should have paid more attention, but it wasnt so much that it was bubbling, more boiling from the heat. That said, in my heart, i think headgasket too :-(