Stevey629

I guess my question regards start up, as many of u guessed. There is smoke that comes out of the exhaust, smells like fuel. But its kinda pillowy, which worries me. I just recently finished flushing my coolant system, and am in the process of burping the air out, because recently the light came on and the temp gauge (stock) was acting erradically. I replaced the thermostat, and coolant. It was a fairly cold night here, but Im in San Diego, so its not ice cold. The crap stock gauge is at warm (middle), and it idles for like 10 mins or so and is still puttin out the smoke. But after running it, it doesnt smoke. I read up on O-Ring Failures, and the symptoms match. I think I need to get the coolant system pressure tested, and hope it seals. and get the radiator cap tested for hydrocarbons to make sure combustion gases aren't getting into the cooling system. Damn. Please tell me this might be something else.

Stevey629

I started it this morning after adding a bit more water, because Im still in the process of burping the air out, because I took it for a spin and heard some gurgling when I came to stops...but after start up, there was a lot less smoke. It was warmer outside, and there was still smoke, but not nearly as much as the night before. Then, the smoke stopped completely, and it seemed fine. It actually took less time to warm up, and there was less smoke. Last night, it took way longer to warm up, and continually smoked.

spurvo

Just to try and make you feel better, remember that the dewpoint at night is a good bit lower than the rest of the day. Means higher condensation. I too get LOTS of condensation burn off at night, even after a 20 minute stop. Love that cool moist 45 degree air! Less in the mornings. If the exhaust gas smells like fuel, you are good to go. You really can't mistake coolant smoke. It smell REALLY heavily sweet. Just keep burping, you're almost there

paw140

Last winter my car would smoke really bad on certain days, depending on humidity and temperature. Sometimes I would have a hard time backing up at night because of all the smoke. But it was just normal condensation, not coolant. You can't mistake coolant smell... its very distinct and smells sweet. Slightly like maple syrup, although some people don't agree with that

Stevey629

Ok, I am still in the process I guess, because I check it every time its cold, and I think I need to add a little under half a gallon or so. I did the start up at night again tonight, about the same temp as before outside, and the smoke stopped entirely, as before, I couldn't get it to stop and just shut the car off. This is was a big improvement from two nights before. Its getting much better, and during the day it doesnt smoke nearly as bad. From what u guys are saying, it doesnt seem like it's coolant. My friend thinks that burning coolant smells like maple syrup too, he smelled my exhaust and said that it wasn't coolant. Right on guys. Thx. So I guess I just have to keep adding to the radiator fill and AST and checking until the levels stabilize. Oh, and I dumped a bottle of Redline Watter Wetter in, some peeps say it helps a lot, and I figure that it can't hurt. Agree? If not, let me know why, so I can drain and start over.

Stevey629

why does my overflow tank (I think) still spooge coolant? Is it because there is too much in there? I drove it for like five or ten mins, and came to a stop back at my house and the overflow tank seemed to be dripping coolant. Tell me this isn't combustion gas please.

paw140

I guess its possible you have a blown o-ring. You might want to change your radiator caps, and check the hose that goes from the AST to the overflow tank. If it is damaged, the hot coolant will go into the overflow tank, but when the engine tries to suck the coolant back in, it gets air.

I had a problem very similar to what you're describing. My car became harder and harder to start, there was white smoke coming out of my exhaust, and then my coolant light started coming on. The coolant was always a little low, so I would fill it up, but then later it would just come of out of the overflow and onto the ground. I though for sure I had a blown coolant seal. But the smoke did not smell like coolant. The starting problem and smoke was caused by fouled spark plugs, and I never did find out what was causing the coolant problem. I put in Bars Leak, thinking I had a blown o-ring, and I've never had any problem since then. I really don't know if I had a blown seal or not, but my car has been fine for the last 2000 miles.

cavellm

See if you reversed the radiator and AST caps. The cap that goes on the radiator is a bit deeper than the one that goes on the AST. From what I've been told, they have different pressures on them or something like that.

After I replaced my radiator I got the two caps mixed up. Whenever I'd get the car warm, I'd be dripping coolant like mad. But only after it got really hot it'd be overflowing out of the overflow tank. After switching the caps it was fine.

paw140

The cap that goes on the filler neck has no pressure release. It completely seals at all pressures. The AST cap is a normal radiator cap with a pressure relief valve.

Nathan Kwok

Another test you can perform is to start the car with filler cap off. If you are getting combustion gasses into the coolant, it'll bubble like soda. People say it looks like "champagne", but coolant isn't exactly as clear as champagne so I would just look at the surface for bubbles popping on the top. Obviously do this when the car is stone cold.

Dragonz818

So if you do start the car cold and it bubbles in the filler neck does that mean you definately have a seal probem? I think I may be having this problem as well. I havent done this trick yet, but My colant is always low and when I fill it it come out of the overflow. I think I may be haveing the same symptoms as Stevey629.

Nathan Kwok

Basically, yes. The vibration of starting the car could shake a trapped bubble in the radiator hose to the top, but if you see a continous stream, it can only be an o-ring leak.

Dragonz818

What about a small leak in one of our hoses?

Dragonz818

I mean could that cause bubbles in the coolant?

Nathan Kwok

If you have a leak in a hose the system will pull air back in after shutdown when the coolant starts to cool, so you can still get air in the system that way (this is actually the most common way air gets into the system). However, when the system is already cold, warming it up pressurizes it, so leaks in the hoses will push out and not pull in. The combustion chamber, however, is always at a higher pressure while the car is on, so it'll push air in if there is a leak on that side.

Dragonz818

I am gonna check it. wish me luck...

ArchangelX

Why don't you get a leak test?

Dragonz818

My car only has 15,000 original miles and these symptoms are very new. I am probably just paraniod but I would rater know. I didnt think it could be a seal until I read this post.

I have no smell from the exhaust, I have no coolant in my oil and my car never ever leaves smoke for more than 2 min after I start it. My coolant does dissapear but I always fill it. I have never had my light come on yet either.

I will probably get it checked now......

Stevey629

Ok, heres the deal....I guess the (stock Mazda) caps that I have actually might be reversed. The one on the filler neck, (metal reservoir up by alternator) basically has one gasket, is not very "deep dished", and has a cap shape like a circle with 2 nubs on opposite sides to help turn the ****. The one on the AST, (dark green tank, Stock) has a circular cap, and has a deeper design to it, consisting of a gasket to go further down in the neck, and a higher gasket inside the top of the cap. I'm assuming that the one that I have just mentioned in the AST right now is the no pressure release cap, and from what u guys are saying, they are reversed.

The symptoms that I am displaying is a very heavy gurgling sound when I rev the motor, that I can only hear from inside the car with the doors closed, due to the engine making too much noise if I leave the hood up and try to listen (I'm guessing). Either way the other symptom that worries me more is the overflow tank spiitin out coolant. This may be happening as I rev, but no doubtedly when I idle it after driving it, or just basically revving it at all...so tell me if these caps are reversed, and Ill switch em'.

Another thing, is that with the "possible cap reversal configuration", I tried taking off the radiator reservoir cap, (single gasket nubbed cap) and ran the motor, and coolant just started to rise up, the buzzer came on, so I closed the cap and shut the car off. I had the coolant system pressure tested a few days ago, and there were no leaks, and just recently replaced the thermostat, with the STOCK MAZDA one. I basically cant figure out how to burp the coolant system properly. However with these caps reversed, I dont think I would be able to.

Nathan Kwok

Well, here is a picture of the AST and the stock cap that goes with it. The AST has the round cap and the filler neck has the one with the ears on the side. That AST is for sale btw, only $20+shipping, has ~20,000 miles, in case anyone is interested .

Stevey629

well, I guess I have them on correctly...just gotta figure out whats wrong with the system then. I noticed a small leak on top of the ast, nothing big, but it could be enough to let air in. So what should I do?

Nathan Kwok

You can always replace the AST cap, they are very cheap. However, the best bet is to get the system pressure tested, that way you can figure out where the leak is. Usually if the system is sucking in air on cooldown instead of sucking the coolant out of the overflow, you either have a bad AST cap or a leak in one of the AST hoses. Also make sure the system is properly burped. Burping is pretty easy, just top the filler and AST, drive around a bit, then top it off, drive around, repeat as needed. If you have a lot of air in there, the overflow my, uh, overflow, so siphon it until it is very low to prevent this. Remember, if you start the car with the caps off, nothing should happen. The system doesn't begin to pressurize until the coolant starts to warm up, so if you start the car cold and it immediately begins to overflow, you have O-ring failure. I'd say on my car it took a good 3-4 minutes before the coolant level began to rise when I tried this myself.

spurvo

Stevey- ANY leak is enough to remove the possibility for the coolant system to draw the coolant back into the AST upon cooldown. The system works like this: As the engine warms up, the coolant expands. Once it reaches 13 psi of pressure in the system, the AST cap (you do have the correct one ) will allow coolant to flow from the AST to the overflow tank. When you shut off the car, the coolant basically stops expanding (unless you are heat soaking, which is most commonly due to not cooling down the turbo housing), sits around for about 20 minutes, then starts to shrink. As it does so, a vacuum is created in the system. This vacuum opens the lower gasketed (spring loaded) brass stopper and allows coolant to be drawn back into the system from the overflow. If there is ANY, SLIGHT hole ANYWHERE in the coolant system, it WILL NOT allow this vacuum to be created, and the coolant will not be drawn back into the system. Air will be drawn in instead. Further, every time you re-fill the coolant system to replace the coolant that was lost, it just gets peed right back out the overflow tank the next time you heat cycle the car. Sound familiar?

What I found on my car was that the AST to overflow hose (the one that comes off the AST cap stanchion and points toward the battery) was leaking. It would seep just a little bit of coolant. I tie wrapped the SOB and all was fixed, though I did pull coolant up the overflow line to be sure I had a solid column of coolant and no air bubbles. I used a turkey baster. I put the small end into the AST overflow hose at the AST end, and orally pulled (I suck so bad...) the coolant up and actually filled the turkey baster a little. I found that pulling the fluid up a couple times worked some air out of the overflow line. Anyway, I slipped the thumb over the filled line, pushed it onto the AST, and tied it off. End of problem.

hope this is in anyway helpful. I also noticed that my upper radiator hose was swolen around its clamp. I replaced all my coolant hoses in self defense. the upper one had a huge split right on the inside, and had been leaking under pressure, reducing the effectiveness of my cooling system. Fully replacing the hoses at 60K miles should be listed as a basic reliability mod, IMHO!

radkins

Dude, this is EXACTALLY whats going on with my car!
disapearing coolant
no funny exhaust smell
coolant tank overflows when stopped and engine gets warmer
no hydrocarbons in exhaust
funny gurgling sound during acceleration sometimes
I'm doing a pressure test tommorrow, but I have a feeling it will come up fine. If so, where do we go from here. How much coolant do you loose? I loose about 2-6 ounces during my 40 mile round trip to work. More on hotter days. It seems I loose less if I run my fans to keep it from coming out the overflow. I also have eliminated the AST.

Stevey629

Thx spurvo. The only thing that I dont get is using the turkey baster. Why do I need to get extra coolant out of the overflow tank? Its not airtight is it, because it needs to overflow, or displace air...So, correct me if Im wrong, but wouldnt just leaving that tank full and letting it purge out the extra coolant and air be okay? Im a retard. Sorry
I think I know which hose ur talking about that is leaking, its essentially the one that is highest up on the AST. I believe mine is leaking, because there are tiny little dribbles of coolant every now and then right underneath it and around the neck, just like u are saying. Could be the caps or other hoses too, so Ill have it pressure tested. Will it be okay to drive to a place to get pressure tested?

So what do I do again? to remove all the air with this turkey baster? I got a slight idea of what ur doin with it, but I need plainer english, or a slightly better description. Sorry for being such a question *****, but I really don't understand the whole pressure system yet. I really appreciate ur patience with it. Really really helpful.