Coolant leak after service/MOT

adrian1982dragon

Hi I'm new to MSE forums so apologies if I have posted this in the wrong area.

I went to a well known garage chain yesterday and had my car serviced and MOT'd. Drove the car for approximately 70 miles and the coolant light came on. I pulled over no further than 1 mile after the light came on and haven't moved the car since, however after filling up the coolant reservoir and turning the engine back on with cap fully on i stood back and watched the reservoir drain completely in around 30 seconds. When I went to check the cap before filling it was loose and was only done up around 50% of the way meaning that the pressure release valve was exposed and letting coolant out of the reservoir. I called the garage and they told me it was probably an engine problem that had forced the cap up and that it was not possible the mechanic failed to put the cap on properly and I wouldn't be able to prove anything.

I was hoping that someone could answer a couple of queries regarding this:

1) Is it possible for the coolant cap to unscrew itself
2) If (and only if) the garage was responsible is there any way to prove this

I drive a Vauxhall Vectra (2008) 1.8 vvt exclusiv

I have booked this back into a garage that I have used previously for years but i'm still hopeful that this is all coincidence as i'm pretty sure there is nothing I could do if they have failed to do the cap back up.

Thank you in advance

arcon5

Unlikely unscrew itself unless the cap thread is really poor.

I'm not sure what the problem is though... you didn't allow it to overheat did you?
If not, fill it back up, put cap on tight and nearly done. Just run it, heater on hot, add some revs - about 2500. If it has a bleed nipple anywhere, some do, a lot don't, then release that until water seeps out instead of bubbles out. Otherwise, i'd run it with the cap off for a few minutes to allow trapped air a route out.

The level will drop as coolant makes its way back round the system and any air locks released. During bleeding top up as necessary.

adrian1982dragon

I've already tried to fill it back up and it emptied in seconds. You could also see the coolant coming out the bottom of the reservoir, however the cap was definitely open about halfway when I first investigated.

I'm going to take it back to a garage i trust to get the repairs done i'm just lost as to how the cap unscrewed halfway if this wasn't an error at the first garage i went to the thread is fine, there is no damage at all!!

Strider590

Out of where exactly at the bottom of the reservoir?

With the cap left loose, the lack of pressure would cause coolant to boil, leading to air inside the engine and spraying profusely from the open filler cap.

The cap can be tough to tighten up, it should within 1-2mm of notch at the front.

worried_jim

Stop taking your car to Kwik Fit/Halfrauds!

Iceweasel

Just to clarify -you have tried refilling the reservoir but the water just keeps on running out onto the ground.

is there not a pipe become detached?

pendragon_arther

This isn't another one of those Newbie 'Hi, I've never posted before but I've got a madeup story to wind you all up with' posts, is it?

Apologies if I'm wrong, but I've seen quite a few.

adrian1982dragon

pendragon_arther wrote: »

This isn't another one of those Newbie 'Hi, I've never posted before but I've got a madeup story to wind you all up with' posts, is it?

Apologies if I'm wrong, but I've seen quite a few.

I am new but it definitely happened i just know very little about cars so don't know what happened.

adrian1982dragon

Iceweasel wrote: »

Just to clarify -you have tried refilling the reservoir but the water just keeps on running out onto the ground.

is there not a pipe become detached?

It only poured out when I switched the engine on after refilling. It was trickling out before the engine was switched on.

It could well be a pipe but I am parked on a busy public road so getting under the car to have a look isn't really an option at the moment

adrian1982dragon

worried_jim wrote: »

Stop taking your car to Kwik Fit/Halfrauds!

I never posted where i took the car how would you know!!!!!!!!

Big mistake won't happen again!

adrian1982dragon

Strider590 wrote: »

Out of where exactly at the bottom of the reservoir?

With the cap left loose, the lack of pressure would cause coolant to boil, leading to air inside the engine and spraying profusely from the open filler cap.

The cap can be tough to tighten up, it should within 1-2mm of notch at the front.

The leak was from the bottom of the reservoir, yes.

The cap wasn't open it was half way open after I checked it from the garage and when I tried to re-fill it the cap was securely closed all the way as I know it needs to build pressure.