HELP-Coolant leak from overflow

[samples]

I have read all other coolant issues and need further advice. I will explain how this issue started and where we are now. We have a 2000 GT, it has about 120.000 miles on it. I drove the car to Texas from st. louis for the holidays. Great trip and no problems. While there my father, (long time mechanic by trade), he gave the car a tune up and and a good once over. While checking the antifreeze he noticed the sludge in the overflow tank, and the cap was also replaced because when he removed it it came apart off in 2 pieces, the gasket portion seperated from the plastic and was adhered to the opening. He let me know the low-down on the dexcool issue and that apparently it was mixed with regular antifreeze causing the sludging. He flushed it out and refilled with dexcool. Drove it back home to St. Louis and had no problems. Then in February the coolant light came on. Added antifreeze to the resivoir and didn't think nothing of it. This Friday the coolant light came on again, the temp showed average @200-210. Later that day I drove about 2 or three miles and without warning the temp. guage went all the way to 260. I immediately stopped the car and added 1/2 gallon of dexcool antifreeze. Saturday morning we found that it is pouring out of the overflow hose. We installed a new thermostat and checked the old one in boiling water. It seems the old one was okay afterall. We are going to flush the system and need to know how to check the water pump to see if that is the problem first.

[pokesmot]

Do you ever hear gargling inside the car from inside the dash?

by sludgy, does it look like a chocolate milkshake? or just gooey?

it could be a headgasket if the car is overheating and forcing coolant back out the resevoir.

check the tailipe for moisture and a "sweet" smell.

[samples]

Thank you for your reply and wanted to let everyone that may have problems like this know the results of our issue. CHECK RADIATOR/coolant resivoir CAP..This was caused by using the wrong radiator/coolant tank lid/cap. Cap should tighten totally, not tighten and then loosen if you keep turning it. Awhile back it broke. It still went on tight but the screw/thread part of the cap seperated from the gasket portion of the lid. It was replaced a few months ago. Apparently the new cap did not fit tight enough. This caused poor circulation and the coolant escaped out of the overflow hose coming out of the coolant resivoir, the car only showed low coolant intermittently then suddenly out of nowhere , 4 months later it overheated to 260 and dumped over 1/2 gallon of coolant., the cars temp never rose past 210 prior to that. We totally flushed out the radiator and also learned that the best way to be sure the radiator is full is by filling it through the upper radiator hose that comes off the thermostat housing. (thanks dad!) The first time we filled it through the tank and it did not do an adequate job. There was no water/coolant in the heater core and the heat blew cold air.. We were bummed thinking that we had big trouble $$. By filling through that hose it is much easier and effective. We are very grateful for that we did not let a shop tell us it was a gasket or worse. I hope our situation can help someone else. Thank you for your replys

[Etuck]

Never EVER put Dexcool back in your car, the moment I got my car, I flushed the DexCool out of it. Dexcool is bad for the V6's even though GM reccomends it. It dissolves your gaskets and gums up engine and makes the enigne leak from the top manifold. Sadly, when I got my car, it was too late and the top part of the engine had to be rebuilt (talk about a fun time). Now, my Trans Am has Dexcool in it, but that's okay because Dexcool is made for those -all aluminum block- engines. Changing out the anitfreeze won't do anything bad to your car, I know I've driven my car almost 75,000 with other that Dexcool anifreeze and have had no anitfreeze related problems.

[coupe]

Originally posted by Etuck
Never EVER put Dexcool back in your car, the moment I got my car, I flushed the DexCool out of it. Dexcool is bad for the V6's even though GM reccomends it. It dissolves your gaskets and gums up engine and makes the enigne leak from the top manifold. Sadly, when I got my car, it was too late and the top part of the engine had to be rebuilt (talk about a fun time). Now, my Trans Am has Dexcool in it, but that's okay because Dexcool is made for those -all aluminum block- engines. Changing out the anitfreeze won't do anything bad to your car, I know I've driven my car almost 75,000 with other that Dexcool anifreeze and have had no anitfreeze related problems.


You sir know nothing about this issue, stop giving advice.

[samples]

I wanted to add to this dexcool theory and the decision I made. When I was contemplating changing out to regular antifreeze because of dexcool theory. .. based on the varying opinions I have read in this forum.. I decided to stick with it. How can I be sure that after draining/flushing all the dexcool out ,that it's completely gone?? We know that when adding/mixing regular with the dexcool it will definitely glob up and cause problems. I had someone unknowingly add regular to my car. I removed the resivoir tank and filled it with "purple power" and hot water .. shook it and repeated this process until all the clumping was gone and the tank was clean as I could get it. I put buckets under the drain to catch the water/superflush as it came out so I could see what was coming out., watching for oil residue and flushing till it ran clear. We chose to go ahead and refill with dexcool . I did not want to take the chance of not getting it all out of the engine.. etc. . My 2000 GT has 120000 mi. and thankfully hasn't been a lemon. I love my car. This was also the first time I flushed the system. I should not of negleted it so long .. The car had 40,000 on it when I purchased it from the dealer in '02, had it been flushed before? I have no clue.. At this stage of the game I felt it best to leave well enough alone and allow the car to operate the way it has with the same antifreeze, why give a transfusion just to see what will happen? I now will "home" flush the system regularly before winter and springtime. I would not wait until 1000,000 miles as suggested. Flush your system before problems occur. This is just my opinion.

[coupe]

Im just sick of people blameing dex cool as the problem of gasket leaks. Its so not true its not even funny. It has nothing to do with it, the design of the engine is whats causing a problem, not the dex cool.
I have mixed anti-freeze, the "mix with any anti-freeze" stuff and have had no problems from doing that. Well of course when i did that i was in a bind and had no choice. So far no problems, it needs a flush soon anyway but yet still no problems.

[MantaGreen97]

Originally posted by coupe
You sir know nothing about this issue, stop giving advice.

LOL. I think "sir" is an incorrect term. Say's she is 19 and Female at the side there ;)

I wouldn't have used such terminology as "you know nothing about the issue", lol; but I would say that DEX-COOL is not really the problem. It really hasn't been proven conclusively that it is the problem and there is a lot of evidence that shows it is not the problem of the coolant leaks.

This we've been over a zillion times though. I would add however that though using another coolant is usually okay, you shouldn't use the green standard old-skool stuff just because it has silicates in it. The cooling system was designed for DEX which is a silicate free coolant. Using another coolant that is silicate free is a better idea, though I still don't see the harm in using DEX.

[Etuck]

Thank you for the correction, I hate when people tell me I am wrong, but if they refer to me as a man....then I get angry. True, dex cool may not cause all problems, but I have had 3 Grand Ams and they all have had the same problem.....and it was caused by Dex Cool.

[coupe]

Originally posted by Etuck
I have had 3 Grand Ams and they all have had the same problem.....and it was caused by Dex Cool.

Do you have proof that it was dex cool that cuased it?
Your 3 grandams had intake problems becuase of the design of the engine, had nothing to do with dex-cool.
If it where dex-cool that cuased these problems then why do most GM vehicles not have a gasket leak problem?

[Etuck]

I know Dexcool was to blame a) all of the cars had dex-cool in them from the beginning
b) I work for a car dealer and even though it is not GM dealer, the mechanics know what they are talking about
c) I have had the top part of the engines rebuilt and did not put dex-cool in and the car ran better than it did when it was brand new
d) my boyfriend and his friend went to mechanic school, which was taught mostly on GMs and they were told DexCool is a problem in these engines, yes the design is to blame, but the DeCool only makes it worse.
So, in conclusion, please stop trying to prove me wrong. I understand there can be many factors in leaking and whatnot, but I am also right about the DexCool.

[coupe]

A) So what, that dont mean anything
B)Most mechanics that dont specialize in certain makes and models dont know what they are talking about or are misenformed.
C) You had them rebuilt becuase of the leak, of course they run better, everything was gunked up from the leak. Now that they where rebuilt they run better, no kidding. Coolant isnt going to make your car "run better". They run better becuase they where rebuilt, has nothing to do with the coolant.
D) What school did he go to? Sounds like a non-credited school.

No your not right about dex-cool.

[eric99gt]

Originally posted by Etuck
I know Dexcool was to blame a) all of the cars had dex-cool in them from the beginning
b) I work for a car dealer and even though it is not GM dealer, the mechanics know what they are talking about
c) I have had the top part of the engines rebuilt and did not put dex-cool in and the car ran better than it did when it was brand new
d) my boyfriend and his friend went to mechanic school, which was taught mostly on GMs and they were told DexCool is a problem in these engines, yes the design is to blame, but the DeCool only makes it worse.
So, in conclusion, please stop trying to prove me wrong. I understand there can be many factors in leaking and whatnot, but I am also right about the DexCool.

and everyone that has told you these things......is wrong. Show to me other GM motors that use dexcool......besides the 3x00 series.......that have gasket problems. Then I'll believe you

[coupe]

Thats what i tried to tell her, her logic is pretty warped.

[HussyBiker]

This is my 1st post as I am a newbie, but I recently purchased a 99 GT 3400 and have had the LIM gasket replaced and put regular antifreeze in as a replacement to the Dexcool...will this cause gunk buildup issues? We are still having the cooling problems and have decided to change out the water pump...any advice?

[coupe]

No it wont hurt anything but yet there was no point in switching from dex-cool.
What are your cooling problems? These engines run hot, just the way they are.

[HussyBiker]

After replacing the LIM gasket the heater was acting weird...upon turning it would blow out warm air, but when going forward it would blow out cold air or none at all. We opened the reservoir cap and the coolant overflowed...we bled/burped the system and it was still getting hot.

[coupe]

Keep bleeding it, you still have a bubble in there somewhere, sometimes it is tough to get the bubbles out.
How hot is the engine running?

[HussyBiker]

Not sure if we're burping/bleeding it properly...we take the reservoir cap off with the bleeder tightened, rev it up (doesn't seem like the t/stat is opening though. The temp isn't too hot (cooler than normal) but the heat is still blowing cold air.

[coupe]

Well what i do is open the bleeder valve (with the resevoir cap closed) and run the car till it starts spewing out and then tighten it down. You could always have the system flushed professionaly if you are tired of dinking with it.
There are 2 possible and likely reasons its still blowing cold air.
1. your t-stat isnt opening and needs to be replaced
2. you still have an air bubble (this is my guess since you are still getting hot air from time to time)

[HussyBiker]

seems to have worked we're getting hot air from the heater and the temp is less than 200 F...I think we're onto something here! Thanks for your help!

[coupe]

Anytime, sometimes the air bubble can really get trapped and can be a real PITA to get out. Sometimes its so bad you have to have it profesionaly flushed.
Did it end up just being an air bubble then?

[HussyBiker]

there must be more air bubbles cuz the heater is still acting up...would you suggest we take it in to have it bled? do you have any other suggestions? it seemed to work for a little while, but the more we play with the bleeder valve and putting on and taking off the cap more air must be getting into the system...what do you suggest?

[HussyBiker]

also...the lower hose coming off the water pump is cool to the touch and the other upper hose is hot...it seems like the coolant is traveling to the heater core, but not beyond.

[coupe]

Sounds to me like you have a massive air bubble.
Its not anything you did wrong, it happens.
Happened to me on my 92 culass supreme (3.1L). I ended up having to take it in and have it pro. flushed. Since flushes arent that expensive i would just take it in. They will hook it up to a machine and force the air out with brute force basicly.
If you do take it in please report back and let me/us know if it worked.
I dunno why but its been bothering me all day that you cant get it out and makes me wanna drive to your place and check it out considering your in michigan too lol

[eric99gt]

Sounds like you're opening the reservoir cap when the car is running. I'm not totally sure on the procedure but you probably shouldn't have that open when the car is running. Just use the bleeder.

[HussyBiker]

Thanks for all the feedback...we stopped opening the reservoir cap and just bled from the bleeder and it's still getting the air out. I've been taking it around the block and coming back to bleed more air out. The heat is starting to blow HOT at a more consistent rate now...looks like we've bled it pretty good. Gonna take it for a longer drive and see what happens. Thanks again...I'll keep ya posted on the happenings, but I'm keeping my fingers crossed that we don't run into anymore problems. The LIM gasket, thermostat and water pump have all been replaced. It's not overheating anymore and the heat seems to be operating properly. Temp is consistently around 205 so again I'm keeping my fingers crossed. Thanks again.

[HussyBiker]

STRANGE...we had to add more antifreeze from all the bleeding going on and now we have the heating issue again. Gotta re-bleed the system *sigh*. I read up in this thread that if you fill with antifreeze through the upper rad hose near the t/stat hsg it may fix the problem. We're gonna try it, but I suspect we'll have to bleed it again. Has anyone else determined that every time you open the reservoir cap...you gotta re-bleed or is it just my luck? The 1st thing we replaced on this car was the cap because it was broken in two pieces just like described above in the earlier thread. If we don't put it on just right air must be getting in the system...what a CROCK of POOOOOO!!!!!! At least it's not overheating anymore, but I'm thinking the coolant isn't circulating well through the heater core...any thoughts, comments or advice?

[HussyBiker]

upper radiator hose was full of coolant...not the problem...any idea how to tell if the heater core is bad?

[jberaue]

For all those that are mechanically inclined here is my issue (most of these points are I believe relevant to my cooling system problem/overheating issues):
99 GAGT with 3400 engine and 70,000 miles
Two months ago Check Oil Light came on for the first time ever - checked my oil and it was full and clean
Last week I installed headers and removed all the stock heat shields. Drove it for a couple days without any issues but did notice increased underhood temps.
Overheated - temps went up to 220 then on to 240, lost about a gallon of antifreeze/water from the overflow hose in the reservoir. Went to add more coolant to get me home and noticed the reservoir had lots of orange-rusty colored sludge. Turned the heater on to suck hot air out of the engine bay but the heater would only blow ice cold air.
Took the car and had the cooling system professionally flushed and had a 180* T-stat installed. Problem solved for another couple days and then it overheated again. There are no noticeable external leaks from either the water pump or the LIM gasket (it only loses coolant out the overflow hose when it gets really hot). Water pump is circulating coolant, fans operate normally, and the oil is clean.

Any ideas? Is this possibly in any way related to the headers becasue that's when all my problems started?

[coupe]

Originally posted by HussyBiker
STRANGE...we had to add more antifreeze from all the bleeding going on and now we have the heating issue again. Gotta re-bleed the system *sigh*. I read up in this thread that if you fill with antifreeze through the upper rad hose near the t/stat hsg it may fix the problem. We're gonna try it, but I suspect we'll have to bleed it again. Has anyone else determined that every time you open the reservoir cap...you gotta re-bleed or is it just my luck? The 1st thing we replaced on this car was the cap because it was broken in two pieces just like described above in the earlier thread. If we don't put it on just right air must be getting in the system...what a CROCK of POOOOOO!!!!!! At least it's not overheating anymore, but I'm thinking the coolant isn't circulating well through the heater core...any thoughts, comments or advice?

The only experiance i have with a heater core going bad is when it is loosing coolant.
I seriously think you have big arse air bubble stuck in the heater core or the t-stat housing or the water pump. Seriously take it in to have it pressure flushed.

[coupe]

Originally posted by jberaue
For all those that are mechanically inclined here is my issue (most of these points are I believe relevant to my cooling system problem/overheating issues):
99 GAGT with 3400 engine and 70,000 miles
Two months ago Check Oil Light came on for the first time ever - checked my oil and it was full and clean
Last week I installed headers and removed all the stock heat shields. Drove it for a couple days without any issues but did notice increased underhood temps.
Overheated - temps went up to 220 then on to 240, lost about a gallon of antifreeze/water from the overflow hose in the reservoir. Went to add more coolant to get me home and noticed the reservoir had lots of orange-rusty colored sludge. Turned the heater on to suck hot air out of the engine bay but the heater would only blow ice cold air.
Took the car and had the cooling system professionally flushed and had a 180* T-stat installed. Problem solved for another couple days and then it overheated again. There are no noticeable external leaks from either the water pump or the LIM gasket (it only loses coolant out the overflow hose when it gets really hot). Water pump is circulating coolant, fans operate normally, and the oil is clean.

Any ideas? Is this possibly in any way related to the headers becasue that's when all my problems started?

Im thinking you have a LIM leak. No your headers wont cuase any mechanical problems, its coincidence (sp?)

[jberaue]

I was afraid of the LIM gasket but figured it's only a matter of time. The funny thing is that there is no external leaking from the gasket and the oil is clean, no smoke from the exhaust, suggesting to me that it is not leaking internally. Even if the leak is slow, I should be able to drive more than the 2 miles I can manage now before overheating. Even the mechanic who did my flush and T-stat replacement noted that there are no leaks at this time.
I'm having another guy look at it tomorrow so we'll see what he says.

[coupe]

I bet you have an internal leak. May be small but who knows how long you drove around with that small leak. Your oil might be clean but that just means your oil is leaking into your coolant.

[HussyBiker]

:mad: LIM gasket replaced even though no noticable leak other than overflow on reservoir too...I bet your LIM is leaking just like coupe says...good luck! We have no heat and I'm assuming a massive air bubble in the system! I refuse to let anyone drive this car until we flush the system professionally. I'm not paying to have the LIM gasket replaced again...it only takes one overheat to cause the gasket to break, so be very careful cuz it can and does happen again.:roll2:

[coupe]

If you have a revised gasket then there is not much to worry about.

[samples]

That happened to us after flushing and refilling the system through the resivoir tank. It turned out we did not have enough antifreeze/water in it. Check the hoses that go into the heater core.. one will not be hot if there is not enough water available to flow /pump all the way to the heater core. It certainly seemed like it was full but we were wrong. The hose from the resivoir going into the radiator is so small and takes a long time to make its way through there and the resivoir stays full along time because it slowly seeps into the radiator. . I called my mechanic father 600 miles away and explained it to him, he told us the above info. and that is what it sounded like to him, and that we should fill the radiator through the upper hose, it's the one that come off of the thermostat housing.(in my 2000 anyway). It was so easy to do it that way and it turned out to be the problem. Now everything functions great and the temp stays between 205 and 210. This may not be your problem but won't hurt to give it a shot. It is great when you try the simple things first and not jump to conclusions. It can be so stressful that we tend to overthink and miss the obvious. I enjoy this forum I believe everyone means well. Good Luck

[coupe]

Thats worth a shot also, give it a try.

[samples]

Double check your cap on resivoir tank too.. Mine was loose to where it would tighten, I thought, but if I kept turning it, it would loosen. I had to replace the original and was sold the wrong cap and didn't realize it at the time. This is where the troubles began but it took 3 months before it leaked large amounts. The coolant light started to come in intermittenly, once a month or so. One night it overheated and dumped over 1/2 a gallon of coolant we checked everywhere for leaks and finally fould the resivoir overflow pouring out fluid. We thought there was a clog. Before that I would add a little coolant and it would be fine for a long time. So..we went to napa and was sold the correct cap for around $12.00. The cap should be totally tight . It turned out that this was the whole cause of the car overheating .. the car was leaking through the overflow in the resivoir tank. It started doing it slowly and was hard to detect how the car was losing coolant. Eventually it got worse real fast and the temp shot up and buried the needle. We thought the worse and were bummed.. turned out to be simple but it also could of caused a gasket problem or worse. So far so good. Good luck with your issue.

[samples]

Another troubleshooting tip, from DAD!! I haven't read that anyone suggested this to try.. Check your exhaust pipes while the car is running for any liquid in your pipes. Stick your finger in it. It is okay that there is a small amount there but physically smell or taste it.. that is what I did.. for antifreeze/oil mix. If there is no antifreeze smell and taste that is a good thing. SMILE.. If there is then you most likely have more serious problems.

[ENGGUY]

The newer Prestone "green" antifreeze says on the container that it will mix with any of the other color antifreeze's.
It is also 150,000 mile stuff. Prestone also makes "orange" Dexcool compatable antifreeze, I'm sure they wouldn't make it and sell something they know will goof something up. If I remember it says it is for cars with aluminum radiators though.
So then there must be an electrolytic reaction with such things as brass / copper.

As far as this "argument" goes. To the woman with the boyfriend that goes to auto school, have they shown him head gaskets that are etched by the coolant? Where exactly is the failure at?
If it is the fire ring/seal that goes first then it is not caused via coolant corrosiveness. I have not seen any of these head gaskets yet. But would make a guess that a contributing factor is over heating, and head distortion.

Are there any metal bands in these gaskets that are around coolant holes? Or are they sandwitched double sided steel or
"?" shims?

[jberaue]

Got my car back from the guy in town today... He started by doing a pressure test of the cooling system (not for individual cylinders though) and found no leaks which was good. Also saw that the plastic O-ring on the coolant reservoir was toast and got a new cap for it. Flushed the system again and burped it. He drove 6 miles and said it performed well although got up to operating temp very quickly but then hung at 220 the rest of the time. At idle it seemed to get even hotter so he checked the fans and found nothing wrong with the hi and lo settings. He said it's an issue he "has to scratch his head over." Although there is no obvious LIM gasket leak he can't rule it out and recommended taking the engine apart to see if that would help. I'm going to drive it tomorrow for more than 6 miles and see how it behaves. Before doing the LIM I'll probably try a few of the tips everyone here has suggested. Thanks a lot for all those who have contributed their input.
JP

[djdanger]

Have you got this problem corrected? If not let me know, went through something just like this

[tdewitt27]

one question does your car take 2 or 3 tries to start? beacuse what many people forget about is when you have lim it takes away compression in the engine and that is a tell tell sign of a lim.

[Wedge]

I had this exact same problem. Coolant leaking out of the overflow tube. It especially did it after I shut the car off.

I replaced the radiator cap, and haven't had any problems sense. It has been 2 weeks with no leakage.

[prescill]

Ok here we go, I went through all the stuff you guys went through and it tuuned out to be the head gaskek leaking, pressure testing doesn't show it either, have to do cynlinder testing to find it. Mine was leaking in three different cyn.
Back in october temp went way up to about 115c (239f) and then back done to 70 c and it kept doing this, and every time I was losing coolant out the recovery tank overflow hose. Got the air out again because that was what I was told it could be, went away for a couple of days and it came back again, but worse, it was heating up to 230c (265f) and loosing all of the coolant, like 8 to 10 litres. Mech said water pump, replaced that, week went buy no problem, but it came back again. Drive about 4 miles enough to get up to operating temp and the temp would start climbing. It went away for awhile but I was loosing coolant all the time, replaced thermostate , was fine running at the garage for a hour he let it run, fans and everything came on. Took it out side to cool down , the mech took it for drive and the temp gage was going to 115 degrees and back down. Brought it back in and did the cynder pressure test and bingo... So save your time and wasting coolant and get those cyinders tested. Even if you have a leaking lim and you only do the lim, your heating issue will still be there because the head gasket is putting exhaust gases into the cooling system. I'am pretty well the expert on this because if you read some of my other post , I have done 3 lims, and 2 headgasket on my 99 grand-am. It took about two months to finally find the problem, because it didn't appear all the time at first..

[djdanger]

Originally posted by prescill
Ok here we go, I went through all the stuff you guys went through and it tuuned out to be the head gaskek leaking, pressure testing doesn't show it either, have to do cynlinder testing to find it. Mine was leaking in three different cyn.
Back in october temp went way up to about 115c (239f) and then back done to 70 c and it kept doing this, and every time I was losing coolant out the recovery tank overflow hose. Got the air out again because that was what I was told it could be, went away for a couple of days and it came back again, but worse, it was heating up to 230c (265f) and loosing all of the coolant, like 8 to 10 litres. Mech said water pump, replaced that, week went buy no problem, but it came back again. Drive about 4 miles enough to get up to operating temp and the temp would start climbing. It went away for awhile but I was loosing coolant all the time, replaced thermostate , was fine running at the garage for a hour he let it run, fans and everything came on. Took it out side to cool down , the mech took it for drive and the temp gage was going to 115 degrees and back down. Brought it back in and did the cynder pressure test and bingo... So save your time and wasting coolant and get those cyinders tested. Even if you have a leaking lim and you only do the lim, your heating issue will still be there because the head gasket is putting exhaust gases into the cooling system. I'am pretty well the expert on this because if you read some of my other post , I have done 3 lims, and 2 headgasket on my 99 grand-am. It took about two months to finally find the problem, because it didn't appear all the time at first..

The reason the coolant system pressure check did not pick it up, is because the leaks were actually pushing compression, into the cooling system. Thus, the compression had to escape somewhere, and was pushing the coolant out through the overflow. I had the exact same problem, only one cylinder though. Fortunately, the head were not cracked, only warped. I sent them to a machine shop, had the heads shaved, and the valve train rebuilt. Hopefully, you'll have no more trouble.