More coolant loss

[perleman]

Hi all, scary coolant loss issue. Car is a 98 2.5 manual with 54k miles on

* 9 months ago one morning the temp light flashed, I topped up with water & took car to JZM in King's Langley. They spent 4 hours looking for leaking expansion tanks, radiators, coolant lines, and checking the head gasket, and found nothing wrong.

* 4 months ago one day the same happened. I took it to PorscheTech in Finchley Road where Andy pressure tested the coolant and found nothing wrong, except a pin-sized hole at the top of the expansion tank through which nothing was noticably escaping (and not worth spending £500 on getting a new tank fitted to fix). I fitted the latest coolant cap BTW.

* On tuesday I drove 300 miles

* Wednesday morning, flashing light, I put in about 250ml water and light stopped flashing

* Thursday morning, flashing light, I drove 2 miles, stopped, inspected it, coolant level was normal & when I re-started, it didn't flash any more!

What are your thoughts - should I be worried about coolant leaking into the engine, or if this was the case would there clearly be evidence of oil in the coolant header tank? Surely a leak would have been detected by the 2 places I took it into? Quite worried now.

[juniinc]

or water in the engine,,,

U could've had a bad level sensor, by- pass 2 sensor wires & see that will make your flashing go away!

[perleman]

Discovered a cracked rad today, it must have been a hairline a year ago that took ages to develop. I'm actually relieved in a way as it explains my recent spate of coolant loss & rules out engine damage issues (for now!)

Questions:

* To change one rad, do they have to spend a while bleeding / draining the cooling system?

* If so, should I save some money longer term by change both rads (car is 10 years old manual 2.5 and neither changed so far) so rust is inevitable I suppose

* How will I know if the AC condensors need doing at the same time / is that common?

Ta

[Loren]

1. To bleed the system right - you to vacuum refill.

2. I would look the other one over real well. It could be that some debris flew up and damaged the radiator (which could also happen on a new one).

3. Inspection and have the AC pressure tested.