overheating?

[GUtsy ute]

Hi there,
went to mechanic, fixed/changed the fan (wasn't running smoothly), flushed and changed the coolant (took an expensive one), checked the thermostat and it is working fine and, the temp. is till hot, even after only 20min of runnin in traffic). Further, when the engine is well hot (from half to three quarter of the gauge) the engine seems to knock, kind of missing a stroke at low rev (1, 1.5) from time to time. High revs no problems (at high rev the temp. goes down quickly). Acceleration is (slow) as usual, consumption maybe bit high?

HEEELP, I don't have a backup car...

Tom

Hi Tom,

Sounds like your cooling system is OK if it cools quickly at high revs and everything has been checked. Do you have a full shroud on your radiator that encloses the fan?
Without a shroud the fan sucks air from the sides and not as much through the radiator especially at slow speed.
This means it is circulating the hot air under the bonnet more and not sucking as much fresh air in from the front.
Another thing you can do is put spacers between the bonnet and the hinges to let the hot air escape faster if you don't
mind the look of the bonnet jacked up at the back.
I have seen vented bonnets as well to draw air in and also let hot air escape.
About the economy, how strong is the spark from the coil?
On my 4.2 I fitted a new coil and extended the tip of the rotor button as the gap between the tip and the pins
in the distributor cap is too big resulting in a weak spark at the plugs.
The best thing to do would be go to breakerless ignition, it's not that expensive and makes a big difference
in economy and performance.
I have seen places that sell the extended rotor buttons, will try to find them again.
Also a good set of plug leads if you don't have them already.
Gee it's easy to spend other peoples money!!!

Cheers Gavin