Jim_rx7

Ok... since the rebuild I've noticed that the coolant needs topped up each time I drive it. (not driven it many times, maybe 8 or so max?)

Car starts fine hot or cold, no issues etc.

Today I also done a "chapagne" test just to see if anything severe is going on.

Started the car up, the vid is about a minute after the car was started, no bubbles whatsoever in the coolant etc. Also, with the cap on, the top rad hose does not go hard straight away etc.

Here's the vid....

http://www.youtube.com/watch?v=cGiNvwMPoXc

It's not exactly close up, but the camera man could see no bubbles at all.

Question... does the car have to be upto temp, ie thermostat open for the champagne test??

What I did notice when looking about was the overflow hose to the expansion tank was sitting squashed under the intercooler. I'm possibly thinking that the coolant could get to the expansion tank, but possibly not sucked back by the engine due to the hose being squashed.

I've not driven it again since I took it for a drive after doing the test, and moving the hose etc.

Any ideas chaps/chap-esses ?

G's 3rd Gen

iTrader: (11)

I would say you have a leak under load that might be small enough not to physically see a drip. Sometimes the leak is so mior the coolant vaporizes before it drips. (Hose not clamped properly, etc.) What is that orange coolant? Interesting. Get a pressure tester and let it sit overnight. Try and source a leak in the morning. With that color coolant you shoudnt have a problem.

Jim_rx7

I suppose if could be anything.

A duff hose, a poor connection from a hose clamp. Duff leaking water pump etc.

I've replaced ast cap, so it's not that.

Carpenter

Do a pressure test. This is better than guessing.

KKMpunkrock2011

iTrader: (5)

my overflow tank is broken and every time I drive it, any excess coolant just sloshes out, but you can't tell until the car is sitting on an incline or you get down and look

Sgtblue

iTrader: (16)

If this was the case, the tank should overflowing. What was the coolant level?

Go48

iTrader: (7)

If you mean you topped up the system at the radiator (not the overflow tank), then your problem may very well be, as you indicate, the pinched hose to the over flow. Also, make sure there are no "air" leaks in the overflow hose. That will cause the same problem.

But, as the Sgt says, the coolant level in your overflow tank would likely be increasing over time as well.

Uwan

iTrader: (4)

I have the same exact prob too. what are you doing topping off every time you drive too.

Jim_rx7

I'm convinced it has slowly been rising.

I'll soon see if the problem is solved when I next take it out etc.

I'm aware that a small hole in the hose would also have the same effect, ie, sucking air back into the block instead of coolant.

If it's not resolved, I'll check all lines etc/replace them.

Jim_rx7

Another thing I just thought of actually, is I don't have a stock upper rad hose. I have a silicon one with a water temp sensor in it.

The water temp sensor itself isn't plugged into anything, but when putting the engine back in the car etc, the inner probe (?) part of the sensor came out of the actual sensor body. I simply pushed it back in for now... but my thinking is if this isn't 100% then this could be causing the coolant issue.

KKMpunkrock2011

iTrader: (5)

lol yup, my buddy who's a diesel mech has a solution to fix it that we'll do when we get the motor out

Zoolander

iTrader: (8)

How big is that sensor probe hole? I would think that would create a bigger leak and you'd see some evidence of something. I had the same problem forever - missing coolant with no visible leaks...had to top off every few drives. I replaced the rad, AST, the 5 front hoses (the easy ones to get to), both caps and the coolant hasn't dipped since. Of course I still check every time I go out, but it's held steady. (Knocking on wood......) Good luck!

Jim_rx7

yeah.. I got some hose for the AST lines.

Today my rad cap just failed tho! lol. New one of those also required.

Also looking to replace rad hose with the sensor in it also.

parid

I had the same symptoms with a pin hole manufacturing defect with my koyo. Took me a couple months to find it. Eventually with the cap open, I found a tiny wet spot on the front of the radiator and was able to barely see it once it got taken out.

Jim_rx7

Well the cap failed completely today. Water was seeping out the very top of it!

Possibly faulty all along? I've ordered a replacement.