coolant overflow when car is shut off

[earthquakes]

Hi everybody!
I'm a newbie here and have searched around this forum for awhile without posting until now. I'm really about to give up on this problem. NO ONE can figure it out, including the Saturn dealership.

I have a 2002 Saturn L300. A few weeks back, I had the pipes to the heater core replaced (it was dripping antifreeze into the passenger floor..yuck!). They also did a flush and replaced the coolant. And of course they pressure checked it then. After that, I took the car on a 100 miles trip, nothing happened, then did another 100 mile trip home, and when I drove into my parking spot, antifreeze came pouring out of the car. Ever since then, every time I drive the car enough to get it really warm, when I park it and turn it off, antifreeze comes pouring out of the overflow tube on the reservoir tank. It only happens when the car is warm, and it only happens once the car is turned off.

The real kicker is that when it first happened, I didn't feel comfortable going back to the Saturn shop, since I knew there was a coolant problem and I didn't want to drive it on the highway (45 miles). So I took it to the GM shop here in town. They pressure tested the system and couldn't find a problem. They checked for exhaust in the reservoir tank and didn't find a problem. They checked the water pump, and didn't find a problem. They did replicate the antifreeze overflow a few times. Then, I said to just put on a new cap for the reservoir tank in case that was all it needed. It didn't solve the problem either. So the next morning, I drove to the Saturn shop. After an hour on the highway, I pulled into the shop, told the mechanic to come out and watch when I turned it off, and of course, it didn't overflow (for once!). I left it with them the rest of the day, and they tested everything...the pressure of the coolant system, the compression, all of the cylinders are perfect, and the head gasket is great. They really tested it all...and then drove it and tried to make it happen again, and they said that 5 times they tried to replicate the overflow and never saw it do anything! I drove the car back home (another 45 miles) and it didn't happen when I got home. So I thought maybe it was really just having the stomach flu, and it was better now
But today, I drove a bit around town, and it happened again. So it kind of seems like when I drive on the highway, for a long distance, it doesn't happen. But around town doing errands, it will puke out a good liter of antifreeze when I turn the car off.
So, all the mechanics are at a loss as to what it could be. And I have to say, I'm about to give up too! What else is there that could be the problem. And it could it be somehow related to that initial work I had done on the heater core pipes / flush of the sytem?

Any advice would be appreciated...I''m willing to try ANYTHING!

~earthquakes

PS. They also tested the temperature sensor I think...and I should mention that the car never overheats... the temp is always normal

[John Dirks Jr]

Every time it overflows, are you filling it again?

It needs to be filled when its at operating temperature. If you fill it cold, the fluid will expand when it heats up, and overflow.

[earthquakes]

Originally Posted by John Dirks Jr

Every time it overflows, are you filling it again?

It needs to be filled when its at operating temperature. If you fill it cold, the fluid will expand when it heats up, and overflow.

Thanks for your response! I have been tempted to just not fill it up so much, but the coolant level light is always on...

Actually, yes, I have been waiting for the engine to cool, and then filling it up to the line again. Which I assumed was proper procedure since the arrow to the line says "Cool". But I will right now try warming it up before I fill it up. Once it is warm, should I fill it up to the "Cool" line?


~eq

[Ex-GMtech]

3 things come to mind.
1) If the air isn't burped out of the system, it will cause this.
2) If the thermostat is only opening partially, it will cause the same issue.
3) You didn't say if anyone checked the radiator. As it starts to plug up, it can cause the same issue, also.
The thermostat replacement is quite involved, but that should not keep you from replacing it. Easy way to tell if the radiator is plugging is to get the car to operating temp and feel the very bottom of the radiator. Be careful, its obviously hot. If it is hot, it isn't plugged.
The air in the system will expand and cause the coolant to overflow. When it cools down, it pulls what coolant is in the overflow back in along with any air. This will repeat itself.

[earthquakes]

John Dirks Jr, I tried just filling it up when it was warm, but it still did it.

I took a video of it, and put it on youtube so I could give you all the link.

http://www.youtube.com/watch?v=0-nQ6PDJ4yc

The engine sounds rough, but it is just the crappy microphone on the camera. When he's screaming "stop", the car had rolled a little bit, so that is why the level gets all shakey then, too. So, we'd driven around, come home, turned the car off, and it didn't do it. I turned it on again, and that's when we started videoing because we saw that it was doing its thing...even though the engine was running (which is interested...up until now, I really only had it happen once I turned off the engine). When he asks about the light, we're talking about the low antifreeze level light.

Here's another video showing it again:
http://www.youtube.com/watch?v=c3Ks3a-DxOI

Originally Posted by Ex-GMtech

3 things come to mind.
1) If the air isn't burped out of the system, it will cause this.
2) If the thermostat is only opening partially, it will cause the same issue.
3) You didn't say if anyone checked the radiator. As it starts to plug up, it can cause the same issue, also.
The thermostat replacement is quite involved, but that should not keep you from replacing it. Easy way to tell if the radiator is plugging is to get the car to operating temp and feel the very bottom of the radiator. Be careful, its obviously hot. If it is hot, it isn't plugged.
The air in the system will expand and cause the coolant to overflow. When it cools down, it pulls what coolant is in the overflow back in along with any air. This will repeat itself.

I first thought it was just air, because it made sense considering what had been done. And then when I did the long trip back ot the Saturn dealer, and the problem didn't happen again, I thought maybe something really did get worked out of the system...but it has happened another 5 times today. I can hardly believe that it would spend a day at the Saturn shop and they wouldn't be able to get air out of the system.... ???

I thought about the thermostat, too, but the shops seemed to check everything, and although I don't remember them mentioning this, I can't imagine that they wouldn't have tested it, if testing it is somehow possible. Or at least suggesting replacing it if they thought that might be it. Is there something I can do to kind of test it? The temperature has always been really normal. Never running hot or cold.

They did check the radiator. Both sides were really the same temp. So everything seems to be circulating nicely.

At one point, I let the car idle, and then I revved the engine. When I did this, water came shooting into the tank (the middle compartment) from the return hose (the one at the top corner at the tank). Pretty strongly. The system was fluctating within ~2 inches (which still seems like a lot to me, but... that's what it did). So, I would rev it, it would get sucked down a little, and at the same time, come shooting in pretty strongly. I think, when it actually does the overflow thing, it is coming in from the same hose, although I'm not totally positive of that. Is there some switch somewhere that should keep it from returning so much fluid? It just fills up so much, that it all comes out the overflow valve. And then the level drops way down. When it was still filling up quickly, I could hear rushing fluid-ish sounds coming from the passenger side of the engine (which I think is where the water pump is? correct me if I'm wrong...I'm not really familiar with this car).

I can't think of anything else at the moment... I'm really not eager to drive it back to the Saturn shop tomorrow, especially since the problem didn't even happen there... and they seemed at a complete loss as to what else to possibly check...

Thanks for all the advice, and please feel free to ask more questions because sometimes I'm not sure what info is relevent...

~earthquakes

[earthquakes]

I should also add that I did run the car for a little while without the cap on. Thinking that would expel air... the problem happened again though.

And I also used the heater and the heater seems nice and warm, so it seems to be circulating from there too.

~earthquakes

[born again]

Somehow, this problem must be related to the replacing of the heater pipes. By the way, by searching this site you would find out that you can change the O-rings on the pipes for a couple of bux for parts and less than an hour of your time. Anyhow, it sounds like there is an obstruction or blockage or trapped air somewhere in the coolant pipes/passages. There should never be coolant "shooting" into the reservoir. It only comes out the overflow pipe as the engine heats up and the coolant expands. Did they do a compression test to verify the head gasket? Is this a 4 or a V6?

[earthquakes]

Originally Posted by born again

Somehow, this problem must be related to the replacing of the heater pipes. By the way, by searching this site you would find out that you can change the O-rings on the pipes for a couple of bux for parts and less than an hour of your time. Anyhow, it sounds like there is an obstruction or blockage or trapped air somewhere in the coolant pipes/passages. There should never be coolant "shooting" into the reservoir. It only comes out the overflow pipe as the engine heats up and the coolant expands. Did they do a compression test to verify the head gasket? Is this a 4 or a V6?

V6

Yes, they checked the head gasket.

[fdryer]

My '03 L300 normal temperature indicates just below the 1/2 mark, 3/8(?), if it helps any. I would consider the thermostat, carefully, because its not accessible by any means as ExGMtech says and may be causing your problems. I have never seen any flow in my reservoir container as your two videos displayed.

There may be one other consideration; that the heater hoses were put in backwards? We had one poster in the past that couldn't get heat in the winter when replacing his hoses. After checking the routing from the engine mounted electric heater pump for quicker heating, it was determined that the hoses were reversed at the pump. As soon as the hose routing was corrected his heat came up fine. As a side note, my heater will put out around 140F.

[earthquakes]

Ya, the guage temp is usually right between the 3/8 and 1/2 mark. even when it is overflowing...it is definitely never higher than 1/2. Thanks for letting me know how your's is working...I've been really wanting to see another car like mine to just know what is normal. And if this shooting back into the reservoir tank via that return hose isn't normal...the problem most likely has something to do with that. But to be honest, I'm not completely where that return hose is coming from and what all could be connected to it (the water pump, the thermostat?)

I'm wondering about the thermostat, too. Aside from air in the system, it kind of seems like the last thing it could possibly be.

I think the heater core pipes are OK, because the heat is working really well.

Also, I live at 7200ft. Not sure if that could mess up the boiling point enough to actually cause this much of a problem. But the saturn dealer is 2000 ft lower in elevation and they couldn't replicate the problem there, which I thought was kind of strange.

~earthquakes

[fdryer]

Well, I thought you needed to know about the mistake in hose routing as there was a definite loss of heating in a previous post of our L300's. The mistake was incorrect routing at the pump. Since your hoses needed O-rings replaced I was wondering if the reverse was put in simply by mistake - it happens. Perhaps a return to the dealer or call up with this question may give them a clue? I think its safe to say that altitude isn't a factor here.

[earthquakes]

Originally Posted by fdryer

Well, I thought you needed to know about the mistake in hose routing as there was a definite loss of heating in a previous post of our L300's. The mistake was incorrect routing at the pump. Since your hoses needed O-rings replaced I was wondering if the reverse was put in simply by mistake - it happens. Perhaps a return to the dealer or call up with this question may give them a clue? I think its safe to say that altitude isn't a factor here.

I'll mention it to them. I think I'm going to go back there in a little bit. ugh.

~earthquakes

[earthquakes]

So, the dealership saw the videos and told me they also thought it was trapped air.

They said to let the car run, and when I saw the level in the tank drop, to losen the cap, as that would indicate the a bubble in the system had reached the reservoir tank and could be let out. So... I let it run for an hour..revved the engine, ran with the heater, ran with the A/C... every combination possible. And there was never any change in the level, and the thing never overflowed. All day. I did errands, and nothing happened. Maybe it only happens on odd numbered days


~earthquakes

[lostwages_ls2]

You have a disconnected hose. That hose connecting to the from of the expansion tank is supposed to run forward and connect to the top drivers side of the radiator. It is NOT an over flow hose. The other small hose to the left should connect to the collant bridge between the intake manifolds.

[lostwages_ls2]

I looked at your video again. The front hose is definately not routed correctly. It should connect to the radiator. See teh attached image. The hose connects to the fitting the top.

[earthquakes]

Originally Posted by lostwages_ls2

You have a disconnected hose. That hose connecting to the from of the expansion tank is supposed to run forward and connect to the top drivers side of the radiator. It is NOT an over flow hose. The other small hose to the left should connect to the collant bridge between the intake manifolds.

Ok...this makes me kind of nervous. Which front hose are you talking about?...the one on the right side? The one on the right side is what I alwasy though was just... overflow: open and not going anywhere. Mine is tucked around towards the back of the vehicle... I see in my manual that it is pointing forwards, although I can't tell where it ends, and if it is actually supposed to be connected to something (the radiator?).

It has always been this way...this hose going to nowhere has certainly never changed. I sure wish I could see a real clear picture/video of how the system is supposed to be hooked up!

~earthquakes

[lostwages_ls2]

Yes. The hose coming out of the front of the tank connects to the radiator.

[Ex-GMtech]

He is correct. The hose he is talking about, runs up behind the headlight and over to the left side of the radiator. If you run that hose back to the radiator, fill the system and bleed the air out, it will more than likely solve your issue. That hose is letting air get sucked back in after the system purges the coolant. Which then makes it worse because now your lower on coolant each time this happens and allows more air to be sucked back in.