resv overflow coolant tank
 

ok my car is leaking coolant really bad...and i figure (hope) that it is the resv overflow coolant tank (and not the engine) because the coolent seem to leak from the front right side of the car where the tank is located... So my question is..is it the tank that is leaking or the engine..and how do u know if it is the engine that's leaking?? Also if it is the tank ...where can i buy a replacement for it beside madaz?? Thanks for the help.

Do you have any other things happening, a lot of smoke on startup?

The tank has an overfill hole to allow it to release extra coolant. What can happen is if your coolant seals are going/gone, the combustion can push the coolant back thru the system kicking it out of the overflow tank.

Also in that area are the coolant lines to the turbos. Those take tremendous amounts of heat and are prone to failing over time.

I would first take a look and see if the turbo coolant lines are leaking. Next, check the radiator hoses and then check the filler neck for the old "bubbles" test.

You should also check the seal at the point where the reserve tank neck enters the reserve tank. That's right it is a two piece deal. As the cars age, the seal (which is really just rubberized tape) deteriorates and coolant will slosh up out of the tank at the junction. I just slathered silicone sealant around the neck at the appropriate level and stuffed it back into the tank.

im having the same problem myself.I fill the damn thing up and then it ends up leaking out the same spot.then the damn buzzer.Where are the coolant lines for the turbos located? general vicinity would be the easiest way for me to find them.Also how can I get acces to the filler neck? do I have to take the right headlight off?

this same thing is happening to me...But has been happening for a while...Managed to patch it up with blockweld...Some people on here will tell you not to use it but it managed to keep me going for an extra 2.5k...Going for rebuild tomorrow....BUT before you go throwing blockweld into your system....while the car is cool open the filter neck and leave the cap off....Start the car and watch the coolant in the neck...If it starts to show tiny champeign bubbles (or larger) then it usually means your coolant seals are gone...If there are no bubbles that's great...from there I would replace both the AST and filterneck caps. If they are leaking they will also cause it to overflow from the bottle...

You will not need to remove the right headlight. The filler neck is attached to the right fender with one bolt. By disconnecting that, you should be able to size up the condition of the seal by following the neck down to the tank and playing with it a little. A flash light will help here. If the seal looks bad, you should be able to work it free from the tank without removing anything else.

all very good information guys.I hope that I get no bubbles when I check it out.I really cant afford to get the engine rebuilt right now.Quick question though.Should I be seeing any bubbles at all.Or just a whole bunch of bubbles means my coolant seals are gone? thanx for the helpfull info.

Ok I checked for the bubbles in the coolant.Not a single bubble.Phew.
Thank god for this one.But the coolant still continues to leak out of the overflow tank.Its too dark to work on the car anymore.I have a good question for you guys though.I remember someone said that the overflow tank has a hole that drains the coolant if it gets too full.Where is this hole located on the tank or the filler neck.Knowing this will help me figure out if the coolant is just overfilled.Which I doubt at this point or if the coolant is leaking from where the filler neck and the tank join.Thank you.

Ok I checked for the bubbles in the coolant.Not a single bubble.Phew.
Thank god for this one.But the coolant still continues to leak out of the overflow tank.Its too dark to work on the car anymore.I have a good question for you guys though.I remember someone said that the overflow tank has a hole that drains the coolant if it gets too full.Where is this hole located on the tank or the filler neck.Knowing this will help me figure out if the coolant is just overfilled.Which I doubt at this point or if the coolant is leaking from where the filler neck and the tank join.Thank you.

The tank should be 1/2 full max cold. This relates to the "F" as in FULL mark on the coolant dip stick.

on my 93, the long neck does not have a seal where it enters the tank ... just a snug fit. this joint is about 1/2" above the top of the tank, and a grometted vent hole at the top of the tank, should levels wrongly get too high.

no bubbles ... replace both caps, and pressure and vacuum test the hose to the tank from the ast .... should be able to slowly and easily sip coolant up from the tank with a mitty vac pump at the ast end, and hold it there.

i have a blitz radiator cap.What other cap should be replaced?

blitz 1.x bar relief cap would be on ast. a plain mazda cap (no spring) would be on aluminum filler neck (beside duct to IC). overflow hose goes from ast to plastic tank.

if ast was eliminated/bypassed, just the relief cap on filler neck ... overflow hose is then from plastic filler neck extension (from FC) to the plastic tank.

overflowing coolant tank
 

Hey Speeddemon7, I had that same problem in the past. It turned out that ever time I would fill the reservoir back up, after I drove it would spit up coolant. I found out that I was simply filling the reservoir with TOO MUCH COOLANT, and when it would expand the it would overfill the reservoir. Like KevinK2 stated, just put a limited amount of coolant in the reservoir. Also make sure that you have the correct caps in the correct places. The pressurized cap goes on the AST, and the regular cap on on the waterpump. If not, your system will not run correctly. At least that was what I was told at M2.

http://home.pacbell.net/sedchew/SIG.jpg

The hole is on the top center between the filler neck and the line to the AST

Thanx for the info guys..i found out the problem of my coolant leak..i performed some of the stuff u guy recommended such as checking the hoses and the bubbles test..everything seem to be fine until i took a look at the overflowing coolant tank ..and noticed there was a crack near the bottom. I think the crack might have been caused by the heat. So do anyone know where i can get a replacement for it? or fix it?

this is the first time ive heard of this.So the 1.3 bar blitz radiator cap I got is supposed to go on the ast? not on the aluminum filler neck correct? Which means I also have to dig up the stock radiator cap and put it on the aluminum filler neck.This may explain why a get this swooshing noise on the passengers side behind the dash after a hard run.Most likely the coolant is boiling inside the coolant lines closest to the turbos or inside the heater core.

A quick test to see if you have water in your motor is put your hand to the exhaust and wait a sec. If there is moisture or heavy condensation on your hand when you pull it away, there is water in the motor. But this may not work on a minimal leak.

Sorry to open an old thread

I got a similar problem which in my case the engine keeps running out of water on some days and on others it can run with a refills. I was told that the water pump might not be circulating the water because the Temp sensor is bad, which cause a valve not to open.

Does the fd have a valve like this? My stock guage acts normal during warm up and never goes above normal.

That would be the "thermostat".

However, if you are losing coolant, and it's not leaking out onto the ground; it's most likely leaking into the combustion chamber and burning off (when would mean you need to have the engine rebuilt).

Are you seeing any smoke out of the exhaust?

No smoke, i see it overflowing out the resivior?