Help! Coolant problems

[dhracer]

I\'m having some coolant problems with my car but I can\'t work out what the hell\'s going on, any help would be much appreciated :cheers

I noticed the car was using a small amount of water (about an egg cup) every time I drove it - (driven the car about 5 times since getting it).  Spoke to the chap who rebuilt the engine and he suggested new radiator caps so I replaced the AST and filler cap but the problem still occurred.

I\'ve since bought a pressure tester and tested the system and it doesn\'t hold the required 20psi (it drops away very quickly).  I can\'t find a leak though :2Confused I\'ve re-done the test after filling everything to the brim (including expansion tank) - initially water ****es out the expansion tank and then once that is finished I get a lot of gurgling in the AST and expansion tank

any ideas?

[interloper393]

does in smoke alot out the exhaust? trouble starting hot or cold.. bubbles in the middle coolant filler when running and the caps off?

[dhracer]

Nope, no smoke.  No problems starting.  Not tried running with the caps off (should I?).  You seem to be hinting at water seal failure but it\'s just had a rebuild with new seals (was seal failure last time) :confused:

[interloper393]

can you see any steam when the engines hot n running? pop the cap off n see if theres any bubbles when its running, its not 100% but may help..

[dhracer]

I\'ve never seen any steam. I\'ll put everything back together and start it up and let you know, is it ok to start up the car without the airbox in (I\'ve started dismantling things, lol)?

thanks for the help :Thumbs-up

[brundish24]

what sort of caps have you got has the ast one got a spring on it and is 0.9 bar and is the filler neck cap springless cos i had the same problem and i had the wrong caps

[dhracer]

I have 0.9 bar AST cap (with spring) my radiator filler cap is also an AST cap (don\'t ask but I was told by re-worx it\'s ok to use one for the filler cap)

Is it ok to start the car without the airbox on?

[brundish24]

well thats how mine was. if i was you i get the proper filler neck cap have a look on rotaryart up top i think they got one if not you can get it from any mazda dealer oh and have a check to see if the hose from the ast to the expansion tank is on as mine was not.

im not sure about the air box but it cant do it any good as its not clean air going in to it

[dhracer]

I was having the problem with a standard cap anyway (and when doing a pressure test the filler cap is replaced with the tester).

Hose from expansion tank to AST is on.

I\'ll put the airbox back on (got to wait till it\'s re-set as I managed to break one of the pipe connections taking it off  :Hammer)

[brundish24]

does the coolant light come on and buzz?

[dhracer]

It did buzz when I first started it to move it onto ramps, when I decided I must have a problem.  Its never buzzed before though

I just tested the old cap and it was knackered, the new one holds 0.9 bar perfectly.  What\'s wrong with using an AST cap for the radiator cap?

[shaunwil]

Check that the AST hasn\'t split, other than that you could have an airlock in the system and the ast is settling it down.

Usually if you refill the coolant it takes a while to settle down.

Did you remove the pipe going into the throttle body when you topped it back up (highest point). You only need to do this if it is loosing alot.

Shaun

[dhracer]

Check that the AST hasn\'t split, other than that you could have an airlock in the system and the ast is settling it down.

Usually if you refill the coolant it takes a while to settle down.

Did you remove the pipe going into the throttle body when you topped it back up (highest point). You only need to do this if it is loosing alot.

Shaun

Pipe to the throttle body?  I\'ve never disconnected that, could you point out where it is please?  The AST seems fine

[shaunwil]

Its not numbered on that image. If you look to the back of the plenum next to the TPS on the throttle body (farthest right at back of plenum assembly) there is a pipe that warms the throttle body intake temp up for cold climates.

Shaun

[interloper393]

here you go bud, Shaun means this one
http://www.rx7.org/Robinette/throttle_body_coolant.htm