Cooling suggestions please

[mikes3]

Hi All,

Just had the thermostat switch replaced as the fan wasn't cutting in (turned out to be a wiring fault in the end). The S3 is now fine while on the move but when I stop and stop the engine the coolant glugs out of the overflow pipe on the expansion tank.

Questions:
Is this down to the stat being wrong (is there such a thing as a wrong stat?)

Should the cap on the expansion tank be like a radiator cap (spring etc)

Anyone else had anything else like this?

Help please as its a bit embarrasing leaving puddles of coolant everytime I stop

Thanks

Mike

[kev s3]

had this once with mine,over filled the swirl tank(think its called that,anyway its the tank thats not the expansion vessel!)after a longish run it over-flowed.after spotting the puddle of coolant (and soiling my pants)i checked it all and has been fine since.stupid boy pike!.one thing you could check is that the cap on the swirl tank isnt leaking,i.e allowing air to get drawn in.this can cause the system to over pressurise.the fan switch should cut in at 80-100'c,easyest way is to see if the fan starts when the car is stationary after its up to temp.also you could check the swirl tank cap is sprung and they havnt got the two caps mixed up.the expansion tank cap isnt sprung,hope this helps,cheers

>> Edited by kev s3 on Thursday 18th July 16:57

>> Edited by kev s3 on Thursday 18th July 17:20

[mikes3]

Thanks for that, got the caps the right way round, fan cuts in, puddle still forms and underpants still getting ruined!

Been suggested to 'bleed' the cooling system which is detailled in Steve Heaths bible, heres hoping!

Mike

[njw]

Had the same on my S3C. The responses were as follows:

1.They all do that.

2.You've got an air-lock.

3.Your swan neck cap isn't working.

4.Too much coolant.

Unfortunatley, I never had the chance to test their theories because one of the clips holding a water hose broke one day and I lost all the coolant. Severe grief!The car was towed to my mechanic who checked everything and completely overhauled the cooling system. He did say however that there was an air lock (possibly caused when I lost the water whilst driving) and my swan neck cap wasn't doing the biz.

Hope this is of some help.

By the way, my fan stopped working due to an electrical fault. The wires were chaffed. I got my mechanic to fit a fan over-ride switch which means I can now check that my fan is in working order with a flick of the switch. Also, it is a wise modification bearing in mind the crappy thermo switch the fan relies on.

Also, on a slightly different note, check all your hose clips. The ones on my car which I think are original were quite flimsy and once the rust sets in, become brittle. I replaced all mine using thick stainless steel clips. They are works of art. (I need to get out more!).

[trefor]

Does it spit coolant out each time you fill it up to where you think it should be at Max? It might be the car telling you it's got too much, some cars seem to like the expansion chamber to be a little emptier. To test this, let it spit some out and watch the level - if it 'settles' further down the expansion tank then I wouldn't worry.

Otherwise there is either too much pressure in the system or the system isn't sealed properly. The latter should be easy, the former could be all kinds of things ...

Trefor/.

[Brm Brm]

Dont want to be a scare-monger but if it chucks coolant out the overflow when you switch the engine off thats a classic symptom of a knackered head gasket.
Sorry!

[trefor]

Yeah but mine does it if you overfill the expansion tank. It spits it out until it's happy with the pressure/water equalisation combo I guess (getting technical there).

T/.

[mikes3]

Hi All, thanks for the replies and the advice.

The winner is...air in the cooling system, helpful chap from Tower Racing described the basics over the phone and all is well now! Seriously thinking of the override switch though...back in the sunshine without puddles of coolant...lifes great again!

Enjoy and once again, thanks

Mike

[tvrforever]

Cool

Seriously glad to hear it... Mark @ Tower (bloody top bloke) is just fitting Mod-wise.com 's two stange and manual override to mine as I type. Always had a manual override on my previous Chim so thinking this has to be even better...

Can't wait for the drive home later.....

>> Edited by tvrforever on Friday 19th July 10:21

[tvrforever]

Guys,

Without a doubt, have a chat with David @ Mod-wise.com! Top bloke who really knows his way around the cars and understands what works.

Had a fitting issue (not David's cause) to my Chimaera and he drove over (without me even asking him to) to see me at 8am this morning and fixed it all - I couldn't have asked for better from a top bloke!

Fully recommended and now have twin speed fans and a nice cool car...

Cheers

Ian

p.s. Just don't ask him what he does with his drinking glasses!