No pressure in cooling system

[Mangraviti]

Hi guys.

I'm new to the forum and I need some help with a k11 micra 2002.

I bought it for 250 quid and drove it from Birmingham to Stoke-on-Trent with no issues. This car was meant to be used to teach the Mrs how to drive.

I then took a learner's insurance, got the Mrs in the car, drove it somewhere safe and quiet then it overheated.

Opened the bonnet the radiator overflow bottle was melted. Literally.

Waited till it cooled down completely and as we were close to home, I drove it for like 1/4 mile watching the temps.

Parked up, orders a new bottle on amazon and waited till the next day. Replaced the bottle without a problem. Drained the system, it has some nasty crystalized coolant, put it all back together, filled it up with distilled water, radiator cleaner, ran it for a bit, drained again, refilled with coolant.

Then I drove it to the supermarket and I noticed some smoke coming out in bonnet. I opened it up and it wa steam from the radiator that had a leak.

Replaced the radiator.

Now, although the temps are fine, there seems to be no pressure at all. The heating works fine, so I eliminated the water pump.
The temps are normal. The car feels and sounds normal. No smoke, no steam, nothing.

But if I open the radiator cap even when it's hot, not even a small hiss. The hoses are not hard when hot either.

Any ideas?

Ps I didn't change the thermostat when changing the radiator. I know u should have but I was in a hurry.

Thanks in advance!

The photos were taken from the melted overflow bottle.

 

[BaioX86]

Im commenting to follow. Never heard of this before.

 

[Twincam-Alex]

Could well have been a badly maintained cooling system. Unlikely to have ever been flushed. Maybe different types of antifreeze had been used in the past. There are now several types on the market some which shouldn't be mixed with others may have caused a chemical reaction.
Now you have flushed the system, did you keep the heater on hot to flush the matrix? Check the thermostat in some hot water and check it opens and check the cooling fan is operating. Hopefully it's now sorted.
An oil change, new filters and spark plugs if not already done will be beneficial.

 

[Mangraviti]

Could well have been a badly maintained cooling system. Unlikely to have ever been flushed. Maybe different types of antifreeze had been used in the past. There are now several types on the market some which shouldn't be mixed with others may have caused a chemical reaction.
Now you have flushed the system, did you keep the heater on hot to flush the matrix? Check the thermostat in some hot water and check it opens and check the cooling fan is operating. Hopefully it's now sorted.
An oil change, new filters and spark plugs if not already done will be beneficial.

I just noticed some decrease in coolant level. Theres probably a leak somewhere. Need to find it.

 

[Mangraviti]

Well I noticed the coolant level went down a bit. I don't know if it's leaking somewhere or what. I can't see any leaks. It could be the radiator cap that is not holding the pressure properly. I'll replace that too and see what happens.
I'll keel you posted

 

[Twincam-Alex]

Some decrease would be normal once refilled. There may be an airlock once this clears the level will go down.
When you take the oil filler cap off is there creamy white gunge on the underside?

 

[Wizzini]

Having similar issues, albeit without the melted expansion tank, no obvious signs of leaks, oil is clean, no smoke in exhaust, temps are solid and no bubbles could be seen in the rad. Going to drop all fluids this weekend, flush and pressure test. Been quoted £1k for a headgasket replacement all fluid etc and 7 hours labour which seems excessive? So fingers crossed it's just something small