i have a S4 NA motor that if been having coolent issues with..i fill it full with coolent and it does not overheat or boil but it pushes the coolent into the overflow and fills the bottle up the eventualy i get the low coolent buzzer goin off..exhaust dosent smell like coolent..when i rev the engine with the cap off it sucks in the coolent and does not push it out so i dont think i have a bad coolent seal. I had this problem with another car and 2 new radiator caps fixed the problem but i put new ones on this car and it didnt help...any ideas?

 

You said the exhaust doesn't smell like coolant, but does the coolant smell like exhaust? With the engine off and cool, remove the filler cap at the water pump housing and smell the coolant. It should have a sweet smell, not an exhaust smell. Start the engine and watch for a constant stream of bubbles. This most often indicates coolant seal problems. I just finished a writeup on this topic:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/coolant-seal-failure-teardown-w-pics-677124/

 

will there be bubbles even if the thermostat isnt open or do u have to wait till its warmed up with the cap off?

 

i went out and smelled the coolent and it dosent smell like exhaust it smells normal

 

clog in the hoses?

if you have the time, i'd pull the water pump and hoses and see if there's something that's blocking the water from moving...i mean, obviously it's moving, but the cycle is being blocked somewhere if it's being thrown directly into the overflow tank

 

is it possible that the thermostat could cause this? what could possibly get in the pump or hoses that would be big enough to clog them? damnit i really need to get this fixed its my daily driver

 

Assuming you don't have an internal leak leaves only the thermostat, the radiator cap, the radiator or the water pump itself.

Are you using Mazda thermostat and rad cap?
If not, try 'em...people report problems with generic replacements.

Highly doubtful there is anything blocking the hoses- the ID is 1 1/2" for goodness sake and that would be a major blockage.
If you've never done so, it certainly wouldn't hurt to replace them but the hoses are unlikely to be the source cause of this issue.

Confirmed proper operation of the fan thermoclutch?

Checked your belt tension lately?
Could the waterpump be slipping...just tossing out easy ideas cause it gets expensive from here on out...

 

the thing is i never see the temp guage go above the normal 1/4 until it gets low on coolent then it goes half way on the guage

 

Fill it at the cap start it and bleed it of air (little plastic screw in the radiators water neck on top)!

 

Have you had this car for a while- this is a new problem- or did you just get it- it's had the issue since I took possession?

How old are the cooling system components?

Again- are you using a Mazda rad cap?

 

im using the mazda cap on the rad which is where the overflow hose is..but have a stant cap on the waterpump housing...ive had this car for a while and put 60k on it with no problems..never changed a water pump or rad or thermostat though

 

Hows the pressure cap? If its bad I wonder if its releasing to much coolent and not holding enough pressure in the coolent system

 

the cap with the overflow hose is a brand new oem cap

 

are u using a s5 rad in a s4?2 rad caps?
With it full, start it and drive it for 30 mins or so when it gets up to temp/pressure keep it running and then do u see it coming out of the over flow or is there a leak some were u cant see until it gets hot? if after this u can see it running out of the over flow
it has to be the cap or a internal coolant seal leak.U may want to take it to some one who has a pressure pump so they can put it under pressure and check every thing out just to be safe!

 

no its an s4 it has a cap on the rad and the waterpump housing it came like that from the factory im pretty sure...while driving the overflow tank fills up then overflows

 

new rad caps no coolent smell in exhaust no exhaust smell in coolent...wtf is wrong with this thing!!!

 

from the sound of it ur car, simply, is overheated. with normal driving it could only over heat if it was not being adequately cooled. and if its not being cooled enough then im assuming ur water is not flowing enough. not flowing enough would lead me to assume that ur water pump is dead. i would check that out.

 

i think i will try changing the water pump but i dont understand why the temp guage shows its not overheating its just overflowing

 

ok i just took another look at it and when i added coolent i noticed a drip around the waterpump here its leaking from the weap hole under the waterpump...so looks like its time for a new pump i hope that fixes it.....thanks for all the input guys

 

I just replaced mine yesterday- same problem, leaking from weep hole.

A tip to make life easier...loosen the bolts holding the pulleys (both waterpump and main) while the belts are still tensioned. Just crack 'em, no point in taking them out till the belts are off.

Good luck finding the replacement pump, too.
Mazda wants $265 and even NAPA was asking $165.
I finally scored a Cardone brand at Checker for $115...never heard of them before but the price was right.
Hope it lasts a while cause paying Mazda's price seems like highway robbery.

 

$94 from mazdatrix

http://www.mazdatrix.com/b9wpumps.htm

 

Im having the exact same symptoms. Can someone take a picture of the water pump and "wheep hole" Does that come out of the firewall because I think I might have the exact same problem.

 

the weap hole is on the underside of the waterpump you should see it dripping when the car is running