Coolant Loss, System, Headache.

Hey guys, long time no post!

So anyway, I've started uni and I have a ritual of checking my car every time I make my 100 mile journey back home every other weekend, after checking it last weekm before I went on holiday 40 miles away with the GF, it was perfect, oil was clean, coolant was right on max, brake fluid was high. Blah Blah, car was in optimal condition.

I checked the car Yesterday before making the journey home, to find that the coolant had gone, gone from Max to Minimum *sat on minimum*, I called a mechanic who said don't risk it, get some more ready mix in or add some water, just to get home, I topped it up with some Universal Orange stuff from Halfords and then some water later on as it was Concentrate, Car was fine, no heating issues, heated up a little faster than usual but that's me being paranoid.

My usual 3 bars stayed throughout the day, then all the way home, I stopped to go to uni and checked levels again, while pressured, then again before I left when the engine was cold, levels were fine.

I headed up the motorway and arrived at the mechanics, levels were perfect.

Today when they had time to look at it, they mentioned that it wasnt keeping pressure, but the oil was perfect, no leaks could be seen around the engine bay, etc, hadnt lost any more.

They're going to do it again tomorrow to double check, since they couldn't do it while it was hot, again.
They reckon it could be as simple as a pipe somewhere, or possibly the waterpump, either way, that makes me a little less worried, they do however think that it could be the head, the cars had the head changed in 09/10, before I was the owner, so I'm not sure how well it was done, but it must of been done well, as there's been no problems in the 40K it's done since then.

Now, I'm really confused to what it could be, why would it not lose any more coolant, but fail a pressure test? What problems should I be watching out for now? It never boiled on the way home, which makes me a little less worried. I fully trust my garage I use, however I'd like to know where I could be standing this time tomorrow.

Thanks in advance, any help would be appreciated.

As a note, it had been icy on Monday, so I'm sure this has something to do with it, but what?!!

Kind Regards,
Chris.

Hi Chris,

I would start with the easy stuff and work up to the expensive.

Its more likely to be a hose or pipe, or the radiator than the head gasket. A tiny pin prick in a hose can go unnoticed, but cause a loss in pressure when tested. There could be some radweld or something similar in the system which may explain a sudden change in the coolant loss.

Turns out it was the rad, £45 part from a local dealer, wasnt a bad fix! Now it's shiny!