OK I have a strange problem on my hands.


It seems that my FD is dumping coolant from somewhere once I shut the engine off. This is strange because when the engine is running, it runs pretty damn cool. I have th fan mod done so I run the fans on high speed while driving since I live in Las Vegas and it is hotter than hell.

I just went out for a cruise and didn't beat on the car at all, parked it, and 5 minutes later came out to a small puddle of coolant on the ground. I can't see any leaks, and all coolant hoses on the car are brand new.

The engine was just rebuilt around 1500 miles ago, so I doubt it is a water seal or anything, plus I don't think a coolant seal would cause a problem like this after the engine is shut down. No visible white smoke or anything like that.

The engine just dumps a small ammount of coolant from time to time after I shut it off. Normally the operating temp at shut off is around 96 degrees celcius or lower.

Anyone know what would cause this to happen or have a similar experience? The coolant dumped on the floor is just enough that the coolant buzzer goes off when you turn the key, basically you have to top it off after this happens.

Thanks

 

Have you checked the level of your overflow tank? If it's too high, it may spit out coolant when the engine is hot.
Also, if the cap on your AST is defective, it may be sending coolant to the overflow tank prematurely. You might want to replace it if it's old.

 

I can agree with you there, but why would it dump enough fluid to cause the coolant buzzer to go off? We're talking a fully filled engine (coolant wise) and it is dumping enough to make the coolant buzzer go off. That's way too much to be dumping

 

Sorry, read the edit...

 

4 main possibilities, some repeated:

1. You had too much coolant in the system
2. Your AST cap is gone to ****
3. There is a pinhole leak in the coolant hose that goes from the AST to the reservoir.
4. Son-of-a-bitch...you have coolant seal failure.

 

Hmmmm alrighty.

Well what can I do besides pressure test the system?

I'm highly doubting I have a coolant seal failure since the engine was just rebuilt like 4 months ago.

I could replace the AST cap, if I can find a replacement. I have an aluminum AST so I know that isn't the issue. I could also replace the coolant lines from the AST to the overflow. I just don't get it...

I've gone over the entire cooling system, it shouldn't be doing this stupid ****.

I don't know how I could have too much coolant in the system, I mean that is what the overflow is for. Fock....

 

This is so frustrating.....especially when I have all new coolant lines. I can't seem to locate a hole in the line from the ast to the overflow, so I'm starting to think that isn't the problem.


Any other ideas?

 

Go ahead and replace the radiator pressure cap if you haven't done so. Also, make sure you've got the right cap in the right spot. The flat cap goes on the thermostat housing, the pressure cap goes on the AST. If you have the flat cap on the AST, you'll have problems.

Make sure the overflow tank isn't too full. If it is dumping out of the overflow tank, you'll have a puddle in front of the passenger wheel on the ground.

This has been covered in depth - you may want to do some searching.

Dale

 

Been searching and all I can find is paranoid people saying your coolant seals are blown lol

I have the caps on the right places (flat on the neck, pressure cap on AST)

Where is the radiator pressure cap?

My overflow tank had quite a bit of water in it before it spilled, I probably overfilled it, but the part that doesn't make sense is that it is pushing out enough water that the coolant buzzer is going off. That can't be normal?

 

Get new OEM caps. Don't get the generic crap from your local parts store.

Stop asking for more advice when you have not followed the excellent advice that has already been given!!!!

 

Um..... you're not understanding my friend. All of my stuff is new for the most part, so I can ask for more advice all I want.

Non of the usual suspects seem to be the problem. The only thing that isn't stock and I have no idea what pressure cap is on it, is the AST. It is the one from RX7.com I believe, it was on the car when I bought it.

I just pressure tested the system btw and there are no leaks....so that is ruled out.

 

Also, will the OEM pressure cap fit on the RX7.com AST??

 

put hose clamps on the coolat line that goes from the ast to the resevior. You can lose pressure there, too. Costs a buck for the two clamps.

 

Already have it clamped but thanks




THIS IS WHAT STUMPS ME GUYS:

Why does it only do it sometimes?? This isn't a daily occurance, it only happens once in a while, but the car isn't hot when it happens.

For instance, I drove the car 3 times today. Only 1 out of the 3 had it happen, which happened to be the 2nd time I drove it. Since I posted this I filled it back up with coolant and drove around some more, and it was perfectly fine. I drove it for around 30 minutes, got it nice and heat soaked, and shut it down with the temp at shutdown being around 91 degrees celcius and no water on the ground. I mean wtf?? Wouldn't you think it would happen more often?

 

Check the coolant bypass hose? Sounds alot like what my car was doing when mine sprung a leak.

 

For the hell of it I'm going to replace that line, even though I can't find a hole in it and I pressure tested the system and it didn't leak. I'll replace that line and the cap and report back.

 

I dont know maybe im talking about the same line everyone else is I dont think I am though. It had a leak on the bottom of it I couldnt see it. Follow the path of the coolant to get you looking the right place, its not invisible, it leaves a nice trail. The hose im talking about seemed to have no effect on the car when running but after it sat for like 10-15 minutes it would dump coolant everywhere and made its way onto nice hot engine parts where it made so much smoke people thought my car was on fire.

 

Thanks bud, I'll replace it

Going to hit up mazdatrix.com in a few minutes.

 

make sure you burp the system?

 

System is burped, like I said, I drove around with this water ammount for almost 3 weeks since the last time I had anything like this happen.

I don't understand why it is so intermittent. Something is weird, I blame it on engine gnomes

 

When you replaced the hoses, did you find callousy crud on the metal pipes under the hoses? Did you remove it?

I'm think out loud, but you have the best evidence you can ask for - a leak. You should be able to trace that leak and figure out which connection isn't quite tight. I would try removing that hose and cleaning the pipe nipple to see if that solves it.

Dave

 

Dave,

I can't seem to find the leak, there is no coolant on the under tray. It seems to come from the overflow, atleast I'm assuming it does since I can't find a leak source any place else and I've checked every coolant line when the leaking occurs.

 

Did you discover the problem with your venting coolant? If not, I can help.

 

I used to have this problem with my fd. Strangley enough just after a re build.

For example i would drive the car to the gas station to fill up. When i got back into the car after paying the buzzer would go off due to the car pissing all the coolant out of the over flow.

The car would also gurgle like it had a pain in the guts as well.

I cured it by replacing the stat which was stuck closed. It was odd because there were no signs of the stat being knackered at all. Temps were stable. Also i replaced the ast pressure cap as a precaution.

Scott

 

I had a similar problem a couple of years ago. I can't remember if it happend more than once though. Basically, I stopped to filll up and noticed the same thing (coolant coming from the overflow tank and on to the ground). I had my car pressure tested and everything came back normal.

I figured there was probably too much coolant in the system but it was wierd because I hadn't changed anything with the cooling system in over a year. Eventually, it just stopped doing it. I can't remember whether my coolant buzzer went off though.

Just to be safe I would follow the advice of everyone else and replace the stat/caps.