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1995 pontiac grand am se 3100 v6…my problem is coolant system related: periodically coolant “spews” from under coolant recovery tank cap. I have noticed also that the “low coolant” light comes on intermitantly and also the coolant gage taps out in the red then the cooling fan kicks on and gage goes to normal between 150 and 200. I have replaced thermostat, upper and lower radiator hoses, trans coolant lines, rubber to metal line that goes from the recovery tank to the neck of thermostat housing, other than replacing the radiator I am at wits end. I am not a professional mechanic but it seems as if the coolant is “backing up” then spewing out the recovery tank as if something is blocking the coolant frm cycling through the engine. I thought maybe one of the new hoses was collapsing so I replaced the upper hose again with a better quality hose. I went up the street to test drive, no low coolant light came on and gage was at normal operation yet when I parked in my drive I noticed coolant spewing out the cap AGAIN. I do not know what else to do and cannot afford to replace the car yet.
Thanks in advance for any advice.
cpd cop 400
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[quote=”wysetech” post=63765]I have had mixed results with that blue fluid. I gave up on that stuff years ago. Now i pressurize each cylinder with shop air and watch for bubbles in the coolant.
Did you change the thermostat to correct this problem? I have seen thermostats that stick when fully closed and won’t open until a high temp is reached. Seems odd that you drove all day without an issue.[/quote]
Oh. I have lived with the assumption that CO2 in coolant can be only one thing. Are you saying that the test has false positives and false negatives? That’s disappointing…. But in this case, for it to overheat so quickly seems out of keeping with a stuck thermostat, but I guess he can always hope. I was thinking it is more likely to be a warped head.
Well spelunkerd, You know it’s sometimes hard to make a diagnosis on this forum. You do your best to help but sometimes you assume things by reading between the lines. With the car right in front of you it’s hard enough.
I haven’t had good luck with the blue fluid. I found that if you get any coolant at all in the tester,that alone can change the color of the fluid.
In cpdcops400 last post he stated that he drove his car all day without any overheating. I never saw a headgasket leak intermittantly. In an effort to help him i’m starting to think of something obscure that could be causing the problem.
Two choices here. 1- Fix the car correctly by replacing the
head gasket and intake gaskets and hopefully be done.#2- Take the 1600+ and find another vehicle.The only problem
is you may be buying what you already got.The problem is when
you start putting more money into the car then what its worth.
Tough call.keep us posted on your decision. :unsure:The thermostat was the first to be replaced because I was thinking of what could cause a coolant back up…a possible stuck thermostat so I replaced it. When it happened again within 2 days, I replaced it again with a little more expensive one only of the logic that it could have been a bad quality thermostat…negative results.
Although I also replaced the upper and lower hoses (nothing was wrong, due to age was replaced as preventative maintenance), I was thinking possibly a slight chance a “collapse” was happening with the hose since was not very expensive. Replaced with a better quality hose with negative results as well.
The metal line (goes from the top of recovery tank to the neck of the thermostat housing) I did replace due to being gunked up at the end. The metal portion of the line was so blocked up I couldn’t even blow air through it. The rubber end (about a 4 inch hose attatched to metal line) was not blocked. Had to get that line from a GM dealer because no one stocked or could get it. I loosened the line at top of the thermostat housing and coolant is flowing fine.
Just one more thing before i start scratching grooves in my head. Make sure that coolant is flowing into the reservoir from the line with the engine running.
Grooves are already trenched into my head!
I drove the car for 3 days this week with no problems…drove it this morning and from cold start temp gage to red, fan kicked on and lowered to normal op temp. Opened hood and coolant spilling from underneath recovery tank cap.
I will check what u are recommending tomorrow. Which of the two hose/lines into the recovery tank reservoir should I watch for? The rubber hose/line from top of the radiator to the tank or the rubber-to-metal line that goes from the tank to the thermo housing?
Thank you!
Thermostat housing to tank. I’m thinking something is floating around with the coolant sometimes plugging the coolant flow to that line.
Grooves are getting deeper too…LoL
wysetech…..UPDATE: With engine running from a cold start, recovery tank cap off and line from thermo housing disconnected from recovery tank (stuck line into a small plastic bottle to catch any coolant) so I can observe. I had my daughter watch the temp gauge as I watched for coolant from line and tank.
As the engine ran for about 5 mins I observed coolant rising in the tank (again, metal line from housing was not connected to tank) and about an inch or less from bottom of the tank opening the coolant level began to lower. Right before the level lowered the temp gauge made it to 220. There was small amount of coolant coming from the metal line into the plastic bottle but didn’t appear to “flow”. I am not sure how it is supposed to flow (heavy or lite).
It wasn’t a steady stream like turning on a faucet, more like turning a faucet off and on numerous times very quickly but coolant was coming through the line. Spitting I guess you can call it. The coolant that was in the plastic bottle was clean so I just poured back into the tank and installed the cap and line to the tank and let the car run longer.
The line from the housing to the tank was very HOT but I slowly pulled it off the tank to check and coolant was coming through line (again, wasnt flowing). Temp gauge never passed 220. Ran the car for 20 more minutes with no issues.
I apologize in advance for such lengthy response but I tried to be as detailed as I could for you.
Thanks again for your assistance, pretty soon my nickname will be Mr. Clean if I pull any more hair out. hahahaIt’s been a while since i checked the flow on one of those but i do remember that the flow was fairly steady especially when you bring the RPMs up but that was after the thermostat opened. That tube is there to bleed off any air that might be trapped in the stat housing. If you have access to some compressed air try to blow toward the engine then recheck the flow.
The only other way is to remove the housing and tube and visually inspect it.I might be barking up the wrong tree but i had one (buick) with a similar problem. The tube was plugged with debris.
If you had not already replaced 2 thermostats i would almost bet that the thermostat was the problem. Don’t mind your lengthy response at all.
Meanwhile…back to scratching.
removed the tube and blew compressed air and line is clear. Brought the RPMs up there is a steady flow of coolant through the line into the tank. (PREVIOUS POST I DID NOT INCREASE THE RPMs WHEN CHECKING THE TUBE)
Been driving the car a week with no problems…THEN this morning from cold start drove a mile to store, temp gauge tacked out to red and coolant spewing from under cap. UGGHHH!!
I did notice that you can not “squeeze” the upper radiator hose a) ITS VERY HOT cannot squeeze for more than couple seconds and b) the hose appears to be hard when squeezed at all when hot and running a bit.
My next step I guess is going to try the Blue Devil pour-n-go head gasket sealant only because of failure of previous test of blue liquid turning yellow.
I had the same issue with my impala. 3.4 is close to the 3.1. my issue was kind of speratic as well. finally replaced the upper and lower intake gaskets and it was fixed. these gm engines had issues with the intake gaskets failing. its not a hard fix at all, just get a repair manual and dig in. if its not the intake, its not that much more work to go down to the heads. I might be wrong, but all the issues you have mentioned were the same for my car. you can get a rebuilt engine for less than $1600 easy.
In one of your earlier posts you mentioned that one of the steel pipes was so corroded with gunk that there was not much room for fluid to move down the passage, so you replaced the pipe. Maybe that same thing is happening inside the engine coolant passages. That is the main reason that mechanics don’t recommend “fix in a can” solutions, which could make things worse.
In one of your posts you mentioned that the cooling fan comes on just as the engine boils over. Have you explored the reason why the cooling fan seems to come on so late? I still also wonder about a warped head, which would explain CO2 in the cooling system.
But all of those things said, if the car is only worth $1600 and if you can’t do the repair for much less than that then you may be better off eating the loss and moving on. Just be sure to be honest with any buyer….
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