Hi guys, Bit of a different one on the loosing coolant. My car uses about 200-300ml of coolant per 200-300kms. Never overheats. I can always read the idle speed and performance and know when the water is getting low. Anyway just had a snap-on pressure tester on the rad cap at 15psi for 45 mins and it was rock solid, didn't move. Can I assume that the water system is ok? I tested the overflow tank and its always got some water in it. So the only weak link left is the rad cap. Normally the Twin Turbos have a 1.2 bar cap but when I needed a new one I could only get a 0.9 bar cap. Would a 0.9 bar cap open to early and vent water into the overflow and that evaporates over time thus water level going down? Any other ideas? Beavis
I tested the radiator Don't have facilities to test the cap but I have just grabbed a 1.1bar cap and I'm going to try that out. I don't understand where the water is going unless the radiator neck is knackered. Beavis
I used a 0.9bar cap for ages when I had a slow leak. Go for it as the high pressure cap wont hold any more pressure.
Cheers for the replies so far. I did some testing with the rad caps I have and I have found that if I give the cap a tug on the right side and wiggle I can get it to come undone, seems like the lip might be worn on the filler neck. If I push down on the rad cap and turn I can get it to seat nice and firm but I think the rad neck might just be worn out. I am using new rad caps and bending the tabs hasn't really helped. I also took out the overflow tank and gave it a good clean, tested for leaks, all ok, checked the hose from the overflow tank to rad neck, all good. Any other places I could be losing water from? Apart form new radiator is there any way to temporarily fix the rad neck? Cheers Beavis
Haha just read my original question, Sorry for the confusion. I was testing the cooling system from the rad neck at 15psi for 45 mins. Beavis
Bend the ears on the rad cap so that it is tighter on the neck of the radiator. This could be where you are losing coolant.
Wrap a wad of paper around the radiator neck and around the outlet of the overflow tank. If you're losing coolant the water soaked into the paper won't evaporate as quick so you'll be able to see if you are losing coolant at these locations.
