Strange overheating problem
07-26-2015, 01:04 PM
#1
Instructor
Thread Starter
Strange overheating problem
On a rather hot day in Florida I ended up with a strange overheating problem.
While I was in stop and go traffic I ended up with a check gauge message and notice the water temp was reading full scale. Temp did go down after I started moving again but kept overheating and got the message reduce engine power. I did not seem to be leaking any coolant.
After it fully cooled down a few days later I ended up adding almost three gallons of Dexcool! i expected to find a leak of some sort, but it seems to be holding coolant fine and cooling system seems to normal, but I have not been in the stop and go traffic and heat I experienced that day.
Not sure what I should be looking at! Fans?
While I was in stop and go traffic I ended up with a check gauge message and notice the water temp was reading full scale. Temp did go down after I started moving again but kept overheating and got the message reduce engine power. I did not seem to be leaking any coolant.
After it fully cooled down a few days later I ended up adding almost three gallons of Dexcool! i expected to find a leak of some sort, but it seems to be holding coolant fine and cooling system seems to normal, but I have not been in the stop and go traffic and heat I experienced that day.
Not sure what I should be looking at! Fans?
07-26-2015, 04:33 PM
#2
Team Owner
On a rather hot day in Florida I ended up with a strange overheating problem.
While I was in stop and go traffic I ended up with a check gauge message and notice the water temp was reading full scale. Temp did go down after I started moving again but kept overheating and got the message reduce engine power. I did not seem to be leaking any coolant.
After it fully cooled down a few days later I ended up adding almost three gallons of Dexcool! i expected to find a leak of some sort, but it seems to be holding coolant fine and cooling system seems to normal, but I have not been in the stop and go traffic and heat I experienced that day.
Not sure what I should be looking at! Fans?
While I was in stop and go traffic I ended up with a check gauge message and notice the water temp was reading full scale. Temp did go down after I started moving again but kept overheating and got the message reduce engine power. I did not seem to be leaking any coolant.
After it fully cooled down a few days later I ended up adding almost three gallons of Dexcool! i expected to find a leak of some sort, but it seems to be holding coolant fine and cooling system seems to normal, but I have not been in the stop and go traffic and heat I experienced that day.
Not sure what I should be looking at! Fans?
07-26-2015, 04:42 PM
#3
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St. Jude Donor '08
Your engine is either USING/INJESTING (head gasket issue) or the engine puked out its coolant somewhere/
Refill it and keep an eye on the reservoir tank level. Make sure that you burp all the air out of the block!
If you have been using it with that low of a coolant level,, I would be looking at the coolant level quite often!!! If it starts dropping, post back here and let us know what you see.
Its a wonder you don't have warped heads.
Bill
Refill it and keep an eye on the reservoir tank level. Make sure that you burp all the air out of the block!
If you have been using it with that low of a coolant level,, I would be looking at the coolant level quite often!!! If it starts dropping, post back here and let us know what you see.
Its a wonder you don't have warped heads.
Bill
07-26-2015, 04:46 PM
#4
Le Mans Master
Fans don't leak coolant.
You don't lose 3 gallons of coolant without a leak unless the aliens took it. I wonder if your coolant tank pressure cap let it go.
Get a pressure tester and see if you can find it. It may be a crack that does not open up until it is hot.
Mr. Sam
You don't lose 3 gallons of coolant without a leak unless the aliens took it. I wonder if your coolant tank pressure cap let it go.
Get a pressure tester and see if you can find it. It may be a crack that does not open up until it is hot.
Mr. Sam
07-26-2015, 05:29 PM
#5
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St. Jude Donor '08
Fans don't leak coolant.
You don't lose 3 gallons of coolant without a leak unless the aliens took it. I wonder if your coolant tank pressure cap let it go.
Get a pressure tester and see if you can find it. It may be a crack that does not open up until it is hot.
Mr. Sam
You don't lose 3 gallons of coolant without a leak unless the aliens took it. I wonder if your coolant tank pressure cap let it go.
Get a pressure tester and see if you can find it. It may be a crack that does not open up until it is hot.
Mr. Sam
ALSO,,, If the engine got that HOT,, CHANGE the thermostat!!!!!!BC
07-26-2015, 06:32 PM
#6
Melting Slicks
With your engine getting that hot, you might also want to change your oil. At a minimum check it. Hopefully it doesn't look like chocolate milk and you find where your coolant went.
07-26-2015, 07:40 PM
#7
Instructor
Thread Starter
Coolant level is holding steady. Not sure how to burp the air out of the block, but it has now been through several hot/cold cycles.
Never have had any cooling issues with this car so this came totally out of left field. Coolant has never been low.
Oil looks fine, but it is about due for a oil change. Thermostat is a easy replace, but I will need to pull water pump to replace A/C compressor which is not working and I will probably wait till then to replace both the thermostat and the water pump.
My "theory" is that it overheated in stop n go traffic (perhaps fans not running when they should) and it puked the coolant pass the cap.
I do have a pressure tester, but I have seen more damaged done by pressurizing operating systems than problems found this way. It is not leaking now, but I would not be surprised that if I pumped the system up it will leak then!
Never have had any cooling issues with this car so this came totally out of left field. Coolant has never been low.
Oil looks fine, but it is about due for a oil change. Thermostat is a easy replace, but I will need to pull water pump to replace A/C compressor which is not working and I will probably wait till then to replace both the thermostat and the water pump.
My "theory" is that it overheated in stop n go traffic (perhaps fans not running when they should) and it puked the coolant pass the cap.
I do have a pressure tester, but I have seen more damaged done by pressurizing operating systems than problems found this way. It is not leaking now, but I would not be surprised that if I pumped the system up it will leak then!
07-29-2015, 08:05 PM
#9
Instructor
Thread Starter
I think I found the problem. It has been fine for several days now, but on the way home today I could smell hot coolant. Popped the hood and saw a drip from the between the bottom hoses attached to the surge tank. Wiggled the hoses a little and the drip got worse. Looks like a cracked surge tank to me.
Ordered a new surge tank and new cap. Apparently GM has replaced the 15psi cap with an 18 psi cap. Anyone familiar with why this change?
Ordered a new surge tank and new cap. Apparently GM has replaced the 15psi cap with an 18 psi cap. Anyone familiar with why this change?
07-29-2015, 08:25 PM
#10
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St. Jude Donor '08
Designed change to give the engine a few more deg boil over protection.
07-29-2015, 09:45 PM
#11
Le Mans Master
Glad you found your vanishing coolant problem...fairly simple fix 
Thank you for posting your findings....
Thank you for posting your findings....