Mk3 GT loosing coolant

Domster · Post by **Domster** » Fri Mar 25, 2005 9:19 pm

Its not overheating and theres no mayo in the cap.
Checked for sure and there is NO oil in the water and NO water in the oil.
I've been advised this could still be a headgasket, I'd just like opinions.
Could it be a leak? Me and my brother have checked all the pipes and can't seem to find anything
Have noticed a few times when its up to temp, I stop and lift the bonnet just to keep an eye on it, and the coolant is at the same level a when I topped up. All of a sudden I heard a pssssh sort of gushing noise as if the water is being released...
The coolant will then be down to the minimum marker, where previously it will have been at maximum.......
any help much appreicated

pete69zx · Post by **pete69zx** » Sat Mar 26, 2005 4:11 am

I could be takling out of my arse here...

Could it be that the system has an airlock in it somewhere?

Just an idea / suggestion

bstardchild · Post by **bstardchild** » Sat Mar 26, 2005 8:47 am

sounds like your header tank cap is letting go and releasing the pressure - result hot coolant not under pressure boils and gushes out past the header tank cap - might be the noise you hear - the other thing could be a loose Jubilee clip expanding and allowing the same thing to happen..... either way you should see a puddle under the car

It has to go somewhere

hardhitter · Post by **hardhitter** » Sat Mar 26, 2005 1:03 pm

yeah, the header tank may not be sealing or the head gasket may be on it's way out. Just because theres no oil in water and visa versa, doesnt mean you rule out it being the head gasket.

DomMk2 · Post by **DomMk2** » Sat Mar 26, 2005 3:09 pm

Yeah

My brothers had a good look and so has a mechanic mate

Took plugs out yesterday and noticed 1 of them is different, on the far left side. weaker or something he said.....he said the gasket may have gone on that side and could be like a hairline crack or something......

amstrange1 · Post by **amstrange1** » Sat Mar 26, 2005 8:37 pm

Doh! That could also explain the funny noise you're getting from that side too.

JWC · Post by **JWC** » Sun Mar 27, 2005 2:10 pm

It is the head gasket. Had two MK3's that started like that. What was happening was that the coolant was becoming pressurised by a pin hole in the gasket. This cased the volume of coolant to increase. Causing it to come out of the header releif valve on longer journeys.

You need to deal with it now, because if it does let go, you risk hydraulicing the engine which is very painful it even rips the engine mounts off!

I know its the HG. I bet you its gone on the front corner of No1 cylinder.

Krupa · Post by **Krupa** » Sun Mar 27, 2005 2:18 pm

Dom as I was saying on MSN the other day, when mine went I had no mayo in the oil, no oil in the coolant either. In fact the engine seemed fine, and was behaving normally aside from one thing.

I called the AA out because I was loosing coolant at a rate of 1 litre every 30 miles and it turned out that my coolant system was at such high pressure it was breaking anything that would give.

It's a pain, but it may well be the head gasket on yours too.

You could probably do it yourself, or if not ask someone on here nicely?

Aside from this your GT's mint anyway, so getting the head gasket done completes the picture. It's a small price to pay really.

hardhitter · Post by **hardhitter** » Sun Mar 27, 2005 6:59 pm

It's also an excuse to get the head flowed

Krupa · Post by **Krupa** » Sun Mar 27, 2005 9:01 pm

Yeah good point, I'd have done that myself if I wasn't dead set on a transplant by the time mine went.