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a lot of pressure in cooling system

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Old 01-03-10, 02:02 PM
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a lot of pressure in cooling system

so i think my coolant seals just went but i want to make sure.

symptoms:
-upper radiator hose is leaking no matter how many clamps i put on the ends
-i can't really tell but it looks like there is more coolant in the reservoir everytime the car is shut off


blown coolant seal? or something like a stuck thermostat?
Old 01-03-10, 02:51 PM
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pressure test it, then youll know if your seals are shot
Old 01-03-10, 03:05 PM
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Classic test is to take the cap off the engine and rev it. If it overflows, you're putting air into the system and your seals are done. I think your upper hose is just shot.
Old 01-03-10, 05:51 PM
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have you tried a new radiator hose?

take the cap off the radiator and pull the injector fuse (the green one)

and put a funnel where the cap went and put some coolant in it and either have someone crank it over for you or you crank it over and have someone watch it. if you get a stream of bubbles its rebuild time. i think you can do a search on the forums and youtube for "champagne bubbles" and you should get results to see what it will look like.

goodluck

thats what i did to just find out about my coolant seals going out.
Old 01-03-10, 07:13 PM
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i get pressure on my top hose as well and my cap on the filler neck leaks because of that pressure i just changed my radiator to a koyo and my thermostat to a lower rating(170) and was wodering why its doing this all of a sudden...i also got one of those caps on the radiator itself with the little valve thing to release pressure and as soon as i open it up the hose gets relieved and all is great but as i drive it again pressure accumulated again... its a 88 na gxl
please help.
Old 01-03-10, 11:31 PM
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if you're overheating and say you fill up the engine with coolant, you run it, and then you see that it's actually spilling out the coolant from the reservoir , then for sure it's the coolant seals, if you're not overheating, but you still have a lot of pressure, then maybe it's your thermostat.... you always want to use a thermostat bought from a mazda dealer, or from worldpack, everything else is garbage
Old 01-03-10, 11:41 PM
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well, the thermostat is a duralast autozone one... t know its not the best one in the world, because i believe the stock thermostat rating is at 190? correct me if im wrong i figured that a lower rating one would open up quicker and prevent this pressure situation
Old 01-03-10, 11:56 PM
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Take the radiator cap off and start the car. Watch the coolant (under the cap) for bubbles. If it bubbles and or foams up it's time for a rebuild. As stated by duo2999.
Old 01-04-10, 12:12 AM
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on the filler cap?
Old 01-04-10, 12:10 PM
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As was said, remove the filler cap on the radiator, not the overflow bottle, start the engine and let it warm up to the point where the top hose feels hot. That indicates the thermostat has opened up. You will see coolant rushing past the open radiator filler neck. That is normal. Don't worry about the minor turbulence or possibly some "gurgling". At that point you are looking for actual obvious bubbling, maybe even foaming, coming up into the filler neck. If that happens, there is almost certainly a failed coolant seal requiring disassembly of the engine to repair.

When doing this, wrap some rags or paper towels around the filler neck to catch the overflow that will happen normally during this process.
Old 01-07-10, 11:01 PM
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small tiny bubbles trickle every other min no foam after a while of start up nothing major, what does that mean?
wat about burping the system?
im going to do it tomorrow morning guys... im do the test again and look for leaks...
Old 01-07-10, 11:19 PM
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Unhappy

Originally Posted by midnightbluefc
small tiny bubbles trickle every other min no foam after a while of start up nothing major, what does that mean?
wat about burping the system?
im going to do it tomorrow morning guys... im do the test again and look for leaks...
The trickling bubbles are telling you air is getting into your cooling system, hence you will need a rebuild if you dont find any leaks.
Old 01-07-10, 11:55 PM
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i kind of figured that. but id doesnt hurt to pressure test the system and take it from there
Old 01-08-10, 12:45 AM
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this is what im getting


[youtubevid]http://www.youtube.com/watch?v=kNIIfJkpu8kl[/youtubevid]
Old 01-08-10, 12:56 AM
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its the exact same thing my car is doing
and this guy said it was bad caps and a loose clamp....i think its gonna be my caps as well...i think its gonna be the fact that the filler cap is a sprung cap...(previous owner, and my lack of knowledge on my 7)but then again that shouldnt matter right?
Old 01-08-10, 11:13 AM
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rebuilt time!
Old 01-08-10, 11:25 AM
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Originally Posted by juan0
rebuilt time!

Don't listen to this.

There are a few here that scream rebuild over the slightest drip of oil on the pavement.

You need to narrow down any and all causes before resorting to such an expensive proceedure.

Take for example, recently, I had a cracked thermostat neck. I would get bubbles like that and air in the system. I did the bubble check and voila, bubble stream. Did I need a rebuild? Hell no, the air was from the crack, and the crack allowed air in during cool down. That air would circulate through the system and get trapped in other places, especially the heater core (when i flicked the heater on, I'd get a water level buzzer). Fixed the tiny, little, almost unnoticeable leak, and burped the system. No more strange air bubbles.

I have been through this THREE times and a rebuild was not necessary.

My point is, go through your options, do all of the test you can do, and most importantly a VISUAL INSPECTION. The visual inspection (a very thorough one) I did all three times is what led me to the issue. I would have missed them if I just took a quick look at stuff and shut the hood.
Old 01-10-10, 12:44 PM
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thanks jjwalker i burped the system and all was good.... i have a leak somewhere beacuse im getting pressure again... its going to be something dumb...
Old 01-10-10, 01:01 PM
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thinking its gona be that stupid stant thermostat..... replacing with oem mazda? or which one would be best?
Old 01-10-10, 04:31 PM
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yea, OEM is probably your best bet. The stant thermostats aren't that great as far as I know.
Old 01-10-10, 09:11 PM
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You DO realize the system is supposed to be pressurized to about 13 psi?
The hose SHOULD be firm and hard when the car warms up?

If your coolant is not returning to the radiator, then you have a leak somewhere. Rent (free) a pressure tester and find the leak. Fix it then you are good to go.
Old 01-11-10, 11:11 AM
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Try replacing the pressure cap. It's only $10 anyway.
Old 01-11-10, 08:40 PM
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uive tried way too many caps already and im thinking its gonna be the thermostat! beacuse when i got the car with the stock rad and stock thermo it was fine no pressure... so imma get a stock one...
Old 01-11-10, 09:34 PM
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get a new set of hoses while you are at it.
The engine depends on cooling.,If that Goes,it is toast,.no drivin,no car.no rotary..I am gonna cry now..Bye!
Old 01-12-10, 11:27 AM
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Originally Posted by midnightbluefc
uive tried way too many caps already and im thinking its gonna be the thermostat! beacuse when i got the car with the stock rad and stock thermo it was fine no pressure... so imma get a stock one...
Definately. Always get an OEM thermostat first with any cooling problem. **** the ones from the auto parts stores. Biggest enemy to engines everywhere.


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