...as above...

can someone also tell me about the coolant tank (passenger-side front corner) as ive heard this is supposed to collect condensation and return it to the coolant system (or something) and doesnt work very well.

Zero, after spending about a grand fitting a koyo rad, replacing every coolant pipe and bypassing the plenum i can safely say my zed doesnt leak.

 

Off to find some wood to touch.

Zero, after spending about a grand fitting a koyo rad, replacing every coolant pipe and bypassing the plenum i can safely say my zed doesnt leak.

 

Off to find some wood to touch.

 

glad to hear it mate :) - so youre not losing any into the engine too. im just a little worried as i also have a koyo, bypass and rebuild and i still need to top it up frequently :(

glad to hear it mate :) - so youre not losing any into the engine too. im just a little worried as i also have a koyo, bypass and rebuild and i still need to top it up frequently :(

 

If your losing a noticable amount id say you deffo have a leak, tubby coolant hoses are common for it but cos they are in such a hot place you never see any on the floor, only other possible is water pump which can sometimes leak under load but not at idle, so you never see it hit the floor cos its only comming out when you driving down the road a 4.5k revs or so.

 

If i were you id take it out for a good blast, then take it somewhere deadly quiet to cool down, like in the garage with the door shut, sit with it for half hour or so as it cools down and listen for hisses or psss noises as water lands on a hot bit.

it seems to be losing a cup-ful every 100 miles. thanks for the tips matey. i hope no neighbours come round while im in the garage, theyll think im trying to gas myself (which, after thousands spent on a rebuild only still to have more problems sounds like a good option!!! :p )

None at all for me:dance:

 

All I've had replaced are the 2 little hoses at the front and the water pump almost 5 years ago; since then I've had the coolant changed twice but I've never had to top it up!!

 

Richard:D

Apologies for the noob question, but how do I measure the coolant level??

 

Doh! Numpty alert...:mac1:

nil in 2 years, flush the system every year and put water wetter in it as well

nil in 2 years,

 

same here :)

mine runs sweet as ;)

It seems to me that as the rad has a pressure cap, with asping keeping it shut until the water gets too hot any water that escapes into the other tank, which is not sealed anyway, will just sit there and can not return because a) the rad ca[p will close when the pressure drops, and b) the overflow tank is not sealed so there is no pressure there to make it return to the rad.

 

And it covers the intercooler. :-(

 

Mine looses a very small amount over some months, and I have chucked the overflow tank in the bin.

I think youll find that the rad cap does allow water back the other way, as after shut off when the system cools the volume of water decreases creating a vacuum in the system the rad cap is designed so that when this vacuum is present it allows water back the other way, so if your tank is in the bin you will be sucking in air.

Not looking to argue, well not in an unfriendly way. But, how does the cap allow water back in? Surely as it has a spring loaded washer sealing the rad there is no way for it to do so. So a vacuum simply causes the rad cap to seal more tightly?

 

The simple fact is (it seems to me) that when the pressure drops in the rad the cap seals the rad, and if there was some "bleed hole" in the cap then it would leak as soon as the temp got up slightly, and as the water in the rad would not be under any pressure the water would boil sooner, and round it goes.

 

And anyway, my car uses so little water that its not a problem, not sure if that makes me correct or not. :-)

Not looking to argue, well not in an unfriendly way. But, how does the cap allow water back in? Surely as it has a spring loaded washer sealing the rad there is no way for it to do so. So a vacuum simply causes the rad cap to seal more tightly?

 

The simple fact is (it seems to me) that when the pressure drops in the rad the cap seals the rad, and if there was some "bleed hole" in the cap then it would leak as soon as the temp got up slightly, and as the water in the rad would not be under any pressure the water would boil sooner, and round it goes.

 

 

The valve can only open one way and that is into the rad, if you take off your rad cap you will see a small metal disc on the bottom of it by the seal, if you put your fingernail under it you can pull it down, this has the same effect as vacuum on it.

 

Go on go out and try it on your rad cap i bet im right!!!

Mine does'nt use any at all :nana2:

Well, the disc I assume you are refering to doesnt move, its the spring with the seal on the bottom of it that moves upwards away from your disc when the rad gets too hot to let the pressure out of the rad.

 

So, I still think I am right. Anyone else?

Well, the disc I assume you are refering to doesnt move, its the spring with the seal on the bottom of it that moves upwards away from your disc when the rad gets too hot to let the pressure out of the rad.

 

So, I still think I am right. Anyone else?

 

It does, put your fingernail underneath it and pull it and it will move.

OK. I will have a look. lol

ok bearing all this in mind about the overflow tank and pressure etc. is there anything in terms of this that could be fooked and cause me to lose coolant?

mine took 10 litres to go to z008 & back, plus put another nearly 4 kettles full in when i got home. do you think theres a problem dave ? :shock::rofl:

Ok, had a look and you are correct, And it does seem to be there to allow the water back into the rad.

However for this to work the overflow tank would need to be sealed and under enough pressure, (after water has entered from the rad) for it to return.

 

On mine there was a silly plastic cap and I seem to remember it not being sealed. But I could be wrong.

 

Sorry, I was wrong.

mine took 10 litres to go to z008 & back, plus put another nearly 4 kettles full in when i got home. do you think theres a problem dave ? :shock::rofl:

 

if youre being serious then id suggest you vote on the bottom-most option!!!

ok bearing all this in mind about the overflow tank and pressure etc. is there anything in terms of this that could be fooked and cause me to lose coolant?

 

Yes, your rad cap would be the 1st thing to try, if that little return seal isnt working then yes it would let it out on expansion but not suck it back on cooling

Ok, had a look and you are correct, And it does seem to be there to allow the water back into the rad.

However for this to work the overflow tank would need to be sealed and under enough pressure, (after water has entered from the rad) for it to return.

 

On mine there was a silly plastic cap and I seem to remember it not being sealed. But I could be wrong.

 

Sorry, I was wrong.

 

The overflow tank doesnt need to be sealed as the point that it dumps and draws from is near the bottom of the tank therefor no pressure is needed in it.

if youre being serious then id suggest you vote on the bottom-most option!!!

 

 

unfortunately, i am being serious, ask duffer lol. looks like its leaking through the head gasket & into the exhaust. seems my rebuild will be sooner rather than later now. am going to get it checked out to be sure first though.

hmm ok ive just been out to look at it in more detail. i have an aftermarket Nismo rad cap with a 1.6km/cm2 rating. perhaps im over-filling the rad - those of you with a Koyo rad, how much do you top the level up to? and how much notice do you take of the overflow dipstick?