59,000Mi

Just recently I began putting coolant into my car every day.. But i dont see where is it is running out of..
I replaced the Radiator cap and the stock AST cap.. and still no luck .. I took apart the line that runs to the overflow tank and it was clogged up with some brown gunk... i got no idea where that came from the car has been in hawaii all its life and now its in PA's harsh weather conditions. .

I cleaned out the line and there was no change in the problem.. I took the radiator cap off and sarted her up and noticed small little bubbles start to come up . and there was light white smoke coming out of the exhaust but i cant tell wheather its jst cold out side or if there is coolant in the engine. its hard to tell it smells like fuel to me. but i do have straight pipe no cat.
. . i just drove her around the block and back to the house and the overflow tank was overflowing .. I released the pressure from the AST and the over flow tank ran over..

Does the tube that goes from the AST to the overflow tank have a tube that goes to the bottom of the tank, or just to the top of the tank?
and is the neck of the tank supposed to be flush with the tank itself?
then neck on my tank looks like it has a gap of about 1/2 inch and that is where the coolant is running out of is that normal??
Or should i be expecting the worst..??

 

I just took the overflow tank off .. there was some nasty brown sludge at the bottom of the tank... Flushed that out and going to put it back on . in a few..
can some one tell me the basic's as to how the AST tank works. is regards to when it activates taking and putting coolant into the overflow. . also .. when i put the overflow tank back on.. do i need to fill that up or leave it empty

 

sounds like u have blown coolant seats

 

Have you changed your coolant recently? If so, all the overflowing may be caused by air-pockets that are within the coolant loop. You need to "burp" the air out of it. There are quite a few threads on this, so a search will give an overview on how it is done.

I'm thinking the loss of coolant can also bea leak. If you can't find the source of the leak, there are many options that you have. The easiest way is to pick up a UV kit. You drop some dye in your coolant (by some, I really mean a few drops). Then run your car under normal running condition for a little bit. After that, bust out the UV light and check out where the leak is. It's really hard to miss, since it glows under a black light.

If that doesn't find any leaks, then you could do a pressure test. Kragen and AutoZone both rent coolant pressure testers. Pump it up to the normal coolant pressure and leave it overnight. If the pressure drops, then you probably have a blown coolant seal (if you can't find any leaks anywhere else). A lot of people will chime in and say for you to do the champagne test, but that isn't necessarily a 100% test to determine a blown coolant seal.

Good luck with your adventure

 

I flushed out the overflow tank and took my fd out for a spin.. supposedly around the block but that ended up to be an 80 Mi trip to Allentown PA and back.. by the time i got back it was dark well any way..
hopefully it was just a clogged AST system..

 

Black goo in the overflow tank or the line going to it usually indicates exhaust gasses escaping into the cooling system (o-ring failure). But like walien said you should pressure test the system and if the pressure drops then pull the leading plugs and see if one of them is wet with coolant.

 

you guys really know how to get some one depressed..

 

Hey, don't let something like that get you down. Be an optimist and think of all the neat port work you can do, not to mention that you will be able to brag to your friends that you have teflon coated coolant seals.

For all you know, you might have just had some air in your coolant loop.

 

I was having a similar problem and discovered my AST cap had failed. A simple replacement and no more coolant loss from the overflow tank.

 

yeah.. that would be nice.. > its just that right now isnt a good time but then again when is.. Maybe 6 months ago when i was in the military .
I replaced both caps a few days ago..
everytime i fill the system i disconnect throttle body.. well i will see what the deal is and if i can get a pressure tester

I was talking to a mechanic yesterday he told me that pressure testing may further damage the seals..
what do you think??

 

I just checked my coolant.. level... and it is no where in sight. I guess i may just have to face the obvious.. The overflow tank was at a higher level what what it was when i filled it up and put it back on. so i dont know what to think.. i am going to fill it up one more time and run it if there is not improvement then its off to the dealer..

I never thought id say that..

well maybe just to the garage for a few weeks first..

 

mazda dealer??? i think that's one of the worst places to take an FD for repairs. Do you have a rotary specialist in your area?

 

you mean like a Puerto Rican? j/k

 

Pressurizing the cooling system to around 10PSI isn't going to damage anything. The cooling system is designed to handle these pressures normally and pressure checking system should tell you where the leak is. After all, what do you think is harder on that coolant o-ring? 1000+PSI of combustion pressure or 10PSI of coolant pressure?

 

I had my coolant seals fail a year and half ago. Just like you i was hoping for the best but the signs were clearly there. Number one and most obvious, the low coolant light/buzzer comes on every morning at start up. Number two, once up to normal operating temps and you shot off its a bit harder to restart...and once it does, its rough for the first couple of seconds or until you give it some gas and dry out the plugs. Number three, and for this one it might help to take a whiff of coolant, the so called "sweet" smell from the exhaust
If you have all of these, its a rebuild you'll need to look into...
On the other hand, if you have air in the system, it will push the coolant out of the overflow...as suggested earlier "burp it" and should be ok... I recently had to refill my cooling system cause i lost half through a torn hose which did 2 things, 1) air got in the system and 2) i overfilled it...both result in loosing coolant at the overflow like yours...my solution was adding just enough coolant and leaving it alone. Eventually the low coolant buzzer stoped and the overflow stoped leaking.
Good luck! and sorry for the long *** post

As for the AST...it doesnt really work as its intended simply because its not at the highest point of the cooling system. The reason most if not all of us delete or replace it is because of the propensity to crack over time.

 

Oh, i forgot.....
You do have a temp guage, right??? If it does turn out to be your coolant seals, you can drive around but they will fali completely eventually and when they do youre stuck on the side of the road depending on how bad a failure you have. Keep an eye on temps but try not to dirve it untill you find out for sure whats wrong with yiour FD.

 

i have been meaning to remave the AST.. just been lazy..
i am going to get a pressure tester right now.. and try it before it gets too dark.. Ill let you know what the results are..
thanx for the info ..

 

Yeah i hear ya...
i am going to put her in the garage for a while..
i saw the little bubbles coming up from the radiator.and i noticed little black specks floating..... the "SWEET". smell as you guys call it .. is present.. now maybe i am just hysterical now but i just started her up and i saw smoke coming up from the left side by the turbos.. looks like another FD may be out of comission for a while..

 

I'm having similar problems man, so I can relate. Except for me I see no bubbles in the coolant. I didn't have an AST, but I just got done installing one and keeping my fingers crossed hopeing that it will solve the problem.

-Charlie

 

Well, didnt mean to piggy back on to your post, but from my latest post about coolent problem, brownish coolent from the block or what not. Well I had a bad overheat last week, and as I have replaced my radiator cap, thermostat , my car would have trouble @ start up, as soon as the motor turns over, coolent dumping out of the overflow ( cool coolent) , and white smoke pouring out of the exhaust for 5 mins, then the car overheats w/ no heat generates from the heater. When the car completely cools down, the pressure in the coolent doesnt drop, but rather would shoot out of the filler neck cap onces the cap was open....This is probably a very bad case of o-ring failure due to a stuck thermostat or waterpump, I have yet diagnosis the cause of overheating, but my car has only a little over 4000 miles since a rebuilt.....Just one questiosn in mind, does a bad waterpump causes the coolent to shoot out of the overflow as soon as I crank the car, even though the engine never fires due to flooding?? I dont think so, I think the exhaust gas is being recirculate into the coolent and causing the displacement!!!

 

A bad waterpump will not cause coolant to shoot out when cranking the car. Exhaust gasses escaping into the coolant system will. If you coolant seals are so bad that they're leaking when you're cranking the motor then I doubt you'll have sufficient compression to start the car.

 

Doing a pressure test tells you that you have a leak but does it mean that it is a bad o ring?

I was just reading something else

http://www.scuderiaciriani.com/rx7/c...imination.html

about the bubbles and not i am confused.. bubbles are normal depending on the coolant / water mixture according to this text..
I am trying to look on the brighter side but i think that my problem is obvious but i am hoping that its somethign else..

I got my FD in the garage now.. and i am reduced to Peach 1998 Lincon continetal..
the only good thing about this car is that it has a handicap license plate/.

 

When my o-rings finally went I could take the filler cap off, start the car cold and by the time the water temp got to 50C it looked like the coolant was at a full boil with specks of black goo floating in it. To do this I used a big radiator filler funnel that fit the filler neck perfectly so that coolant wouldn't go everywhere as it expanded. This was a disturbing sight to see but it left no doubt that I had an o-ring failure.

 

great idea .. I just tried the funnel technique and as soon as i started my car, bubbles instantly started coming up .. and were non stop
I am devastated at my situation but hey at least i know..

does any one have any info on this shop??

as to thier level of work any positive or negative comments..
they are in Queens NY..

http://www.rx7s.com/index.htm

they already quoted me for $2200 to rebuild (stock)
sounds like a good deal.. but IMO it doesnt make sense to go through the work of pulling the engine and just put the same thing back in ..
on top of that.. i dont have the 2 grand to begin with..

 

If you want to save some money on a motor rebuild then talk to www.rotaryresurrection.com but I image your local shop will still charge you $2k for the engine removal and reinstallation. Mazda remans from Malloy Mazda are $2300 or so and he also has brand new motors for $4k and he'll give you $700 for your old motor. Personally I just finished putting a brand new motor in from Malloy Mazda and my car now runs absolutely perfect.