Just before I get it rebuilt...

[Aceman]

Ok..

My car has issues other than this, but this is now it\'s greatest issue..

Coolant leak.. Albeit, not quite leaking, more, being forced into the expansion tank when driving under WOT..

Right.. If I fill the coolant right up (burping the system etc) and let her sit at tick over, all appears fine.

If I then take her for a spin, heating the car up and putting her under pressure, coolant pours very quickly from the system into the expansion tank and then is overflowing and emptying as I drive along. After, say, 80 to 90 miles, once I\'ve let her cool down, started her again, I get the lovely coolant buzzer sound and have to top back.

I\'ve checked the piping from the AST and this is not clogged/seemingly working fine. Simialrly, my AST/"filler neck" cap appear to be good (not leaking externally, but could maybe be sucking in air??).

Anyway, one tuner reckons I\'m looking at the beginnings of a water seal failure - beginings because on the drive I get no bubbles in the filler neck, but then obviously something is pushing all the coolant out of the system when driving hard..

I get smoke out the exhaust, but then I don\'t know what\'s exhaust gas smoke, and what\'s water in the exhaust gas. I\'ll take a video and post to see if that gives any indication..

Any thoughts etc before I cry over rebuild costs? Or perhaps some nice, very cheap checks I could try first?

[Jit]

try a different ast cap first dude. might be a knackered cap - u never know!

[Aceman]

Anyone have a spare? Or know where to get new one\'s from for, I guess, not a lot?

[Prof]

Isn\'t there a chemical test for combustion products in the coolant - which would indicate water seal failure - it\'s likely you are getting pressurizing of the coolant system from combustion.

[SiH]

Yup, most garages should be able to do a \'dip test\' in the coolant to check for the presence of hydrocarbons AFAIK.

Also worth doing the \'champagne test\' - some info on here and rx7club about it, and some videos of good and bad results on Youtube - i believe it was how Matt K finally diagnosed his rebuild need.

[Aceman]

Exhaust on start-up..

Obviously it\'s a little cold..

[Aceman]

Yup, most garages should be able to do a \'dip test\' in the coolant to check for the presence of hydrocarbons AFAIK.

Also worth doing the \'champagne test\' - some info on here and rx7club about it, and some videos of good and bad results on Youtube - i believe it was how Matt K finally diagnosed his rebuild need.

I\'ve looked at a few, but I get nothing like that!

There\'s no bubbles on tickover, although it does kinda rise and fall a lot if that means anything??

[pete sparrow]

If your in Hampshire your not far from Carl Haywards workshop. Go there and get a gas test and a combustion test done.That way you\'ll know for sure if something is on the way out. Should get change from £100 to get those two tests done..

[leon]

I had an issues last week with my coolant peeing out when the car got hot, turned out to be the pressure cap! I ended up cleaning the cap underneeth and flexing the spring put it all back together and its stoped leaking since :2Confused i\'m going to replace the cap reguardless.

[Aceman]

I had an issues last week with my coolant peeing out when the car got hot, turned out to be the pressure cap! I ended up cleaning the cap underneeth and flexing the spring put it all back together and its stoped leaking since :2Confused i\'m going to replace the cap reguardless.

Cool - I\'ve just bought a working one from somebody on here so all my fingers and toes are crossed!!!!

[leon]

Cant hurt to try, Hope it works out for ya :Thumbs-up

[Aceman]

Cant hurt to try, Hope it works out for ya :Thumbs-up

Cheers!!  

[Aceman]

Ah...

Decided to try something a bit stupid this evening..

Ran the car and got it nice and hot (rather than sitting it on tickover) and tried the champagne test again..

I think it\'s kinda gone...  


http://s170.photobucket.com/flash/player.swf?file=http://vid170.photobucket.com/albums/u259/rjpartri/Video011.flv">

[karl_tate]

shame dude,

at least you haven\'t lost a tip or anything like that, so all the parts will be re-usable.

[Aceman]

shame dude,

at least you haven\'t lost a tip or anything like that, so all the parts will be re-usable.

There\'s some hope..

But then only having done circa 8000 miles, I reckon it might be the casing holding the water seal, rather than the seal itself.. I hope not, but that is my fear.....