Coolant Problem Resolved - chuffed!

[planenut]

Originally Posted by pletevl

I'm not understanding everything here, but my ZR started doing silly things, overheating in traffic jams but never when at speed.
The water temperature sensor on the coolant elbow was faulty and not switching the fan on at 104°c

Pete.

Thanks for that, I will add that to my list of items to check.

[drewbie]

Apologies if i've not read this thread correctly. Just a thought, you're not running with both the old type in line thermostat and the later PRV thermostat fitted?

[planenut]

Originally Posted by drewbie

Apologies if i've not read this thread correctly. Just a thought, you're not running with both the old type in line thermostat and the later PRV thermostat fitted?

Thanks for that, no I'm not, oddly enough I keep checking to make sure I haven't missed that.

[T-Cut]

Maybe worth reviewing your earlier thread on this.

Click: http://www.the75andztclub.co.uk/foru...d.php?t=226051

Is the current situation the same as it was?

TC

[planenut]

Originally Posted by T-Cut

Maybe worth reviewing your earlier thread on this.

Click: http://www.the75andztclub.co.uk/foru...d.php?t=226051

Is the current situation the same as it was?

TC

Thanks T-cut, I think I'm about to lose it as something really weird occured this morning, really weird......that's another thread, and some men in white coats.

Thanks again for the referral to the advice and I will now have to refill and then test run and wait to cool again...... before those guys drag me off.

[T-Cut]

In case you don't know, this is a PRT.



TC

[planenut]

I have now refilled the system, and run it up to the "temperatures", and it went on up and up again.

Having filled correctly, then ran it beyond the 88°, the thermostat appeared not to have opened, the fan cut in at 104° and the temperature continued to rise, and I switched off at 109°.

At that stage the rear pipe from the thermostat, and the down pipe to the bottom of the rad was cold. The radiator was hot at the top and cooler to the bottom. The top hoses hot and rigid.

I now have to wait until very cool to check the "cold pressure".

I am going to test the previous thermostat with a view to putting that back in if it's okay.

[Colbo68]

Originally Posted by planenut

Having bored most readers silly with my ongoing coolant problems over the last couple of months, and tried tactfully following the advice, after changing the thermostat, still having trouble with coolant boiling and overflowing the expansion tank, that made me take off the thermostat twice to check it out; then I replaced the inlet manifold gasket, still trouble. then went in to check the jiggle valve in the inlet manifold to find that all gunged up.

After cleaning that and thinking I'd sorted it, still got problems, so with the suggestions checked all again for airlocks.

This weekend was the first chance for a decent run/test and travelled 90 miles, and the temperature kept around the 93, maxed at 95; returned this evening with the same, so I am chuffed as I am convinced it is now solved.

( also no idle problem now as cleaned the inside of the throttle chamber and lubricated all moving parts)

Lol
My coolant problem also seems to be sorted at last.
The car Rover 75 v6 had been using coolant, approx half a cup full a week.
Did a pressure test and the culprit was found to be the water pump.
Water pump now replaced and the problem, for now, seems sorted.

[planenut]

Originally Posted by Colbo68

Lol
My coolant problem also seems to be sorted at last.
The car Rover 75 v6 had been using coolant, approx half a cup full a week.
Did a pressure test and the culprit was found to be the water pump.
Water pump now replaced and the problem, for now, seems sorted.

Nice one, not actually losing water, and hopefully my pump is okay as that was replaced about four years back and there is no dripping.

[T-Cut]

Originally Posted by planenut

The radiator was hot at the top and cooler to the bottom. The top hoses hot and rigid.

The top hose from head to rad top will normally do this.

At that stage the rear pipe from the thermostat and the down pipe to the bottom of the rad was cold.

The rear pipe behind the head goes into the stat. It's the return line from the radiator bottom. It connects to the 'down pipe to the bottom of the rad' - so at the same (cooler) temperature.

Coolant seems to be passing through the rad. Whether it's flowing as freely as necessary is the question. If the flow rate is inadequate, the head temperature will continue to rise even with the fan running. Perhaps you should examine the radiator more closely? You can only do that by taking the front off so you can feel the temperature gradients. The fan MUST be isolated to do this (remove 80amp fuse link in fusebox)

TC