I'm so happy I finally caught a break on my FD! I've been battling a coolant dump problem and had another thread going about possibly having a coolant seal leak. After performing the famous champagne bubble test I was convinced my engine was toast and that I was going to have to spring for an expensive rebuild job. I'd considered everything from a block weld treatment to an engine conversion. Ultimately I was going to veryify the coolant seal leak with an exhaust sniffer over the open radiator fill cap but decided to first just buy a new fill cap from Mazda. I got the cap today ($24, ouch, for a cap?) Tried it out and unlike the cheap cap I got from the auto parts store wks ago when I first started having the problem, this thing actually worked. Now the coolant is being sucked back into the radiator from the overflow tank which it was not doing before; yehaaaaah!

Listen if any of you out there ever have this problem, save yourself some time. Don't just get any ol' pos cap from the stupid auto parts shop. Get the *Mazda* cap! It's different. Also even if your old Mazda cap looks ok like mine did. The rubber in the cap doesn't have to be torn or even look very worn to be bad. What seems to happen is that after a certain amount of time the rubber ring inside gets an indented ring sort of etched into it. This causes it to not be able to make a proper seal and it will give you the coolant dumping symptoms I had.

As for the "champagne bubble test", bubbles are not a good indicator of a coolant seal leak. Could just be small air pockets. The only definitive test is the exhaust sniffer to determine the presence of exhaust gases in the coolant. I never got this far but if it gives me any more trouble that will be the first test I give it. Just take it to any smog station where they can hold the probe over the fill neck with the motor running. If the machine detects exhaust, then in that case the Rotary Gods have *not* smiled on you that day

 

Congrats!.

 

sweet, good to hear you dont need a rebuild

 

That's my philosophy: start with the simple and cheap stuff first before you go running off screaming into the night.

 

Half the satisfaction of owning a FD is fixing the problems it has

Good work!

 

Yeah what's that line? "Back in the saddle again!" Can't wait to take her out for a drive today!

 

Too bad you didn't get any good advice from your last thread ................. oh wait!!

 

: LOLZ

 

Come on Adam, now i said I appreciated your advice in that last thread. I noticed you left that part out of your quoting. The fact is that is was the cap on the filler neck, not the cap on the AST. The air pockets were not causing the problem. You see when the cap leaks the vaccuum pressure as it cools is not enough to suck the coolant back into the radiator from the white plastic overflow tank. The result is that you keep flowing more and more coolant into the overflow tank until it spills out and none goes back into the main cooling system so you have to keep topping it off. Anyway problem solved and I hope this thread helps others. I went down a bunch of wrong turns before I finally started going back and retrying the cap thing with a genuine Mazda part. Don't be a Debbie Downer.

 

hmmm, my buddy is loosing alot of coolant, I didn't even think about this. *picks up phone and dials buddy*



Thanks man! And congrats on not having to rebuild the motor!

 

I hope there is a lesson for everyone there. Don't buy **** parts for your nice car.

OMG!!!!! ..............

 

Glad you caught the reference to Saturday Night Live.

 

Yeah so take it from Adam. Buy solid gold valve caps for your tires. That'll make it run better.

 

Yeah, and if you can't find gold caps, its time to rebuild your engine ...............