LS3 Overheating - Help!!
04-23-2018, 04:10 PM
#1
LS3 Overheating - Help!!
I have a 2008 Corvette LS3, with no modifications. Just a stock car.
It just started running hot on me, so I did all the usual things to check to see if I could fix this problem without going to a mechanic:
1) Checked thermostat. Opens at 180 degrees.
2) No leaks found after putting newspaper under the car to spot the leaks.
3) Tested radiator fan (jumped the connector) and it works fine.
4) Tested fan module (jumped control wire to ground. Works fine.
5) Tested the coolant temperature sensor, and wiring. Seems to be working fine.
Reads 2K Ohms cold and goes down to 700 ohms hot. Connector disconnected reads 5VDC
Still overheats (>230 Degrees - boils over), and the radiator fan never comes on, unless when I remove the coolant temperature sensor connector, the fan comes on immediately, but I can't see the engine temp, so I am scared to drive it that way.
What else can I check before submitting to a mechanic to run diagnostics on this car and charging me the big bucks???
HELP!!
It just started running hot on me, so I did all the usual things to check to see if I could fix this problem without going to a mechanic:
1) Checked thermostat. Opens at 180 degrees.
2) No leaks found after putting newspaper under the car to spot the leaks.
3) Tested radiator fan (jumped the connector) and it works fine.
4) Tested fan module (jumped control wire to ground. Works fine.
5) Tested the coolant temperature sensor, and wiring. Seems to be working fine.
Reads 2K Ohms cold and goes down to 700 ohms hot. Connector disconnected reads 5VDC
Still overheats (>230 Degrees - boils over), and the radiator fan never comes on, unless when I remove the coolant temperature sensor connector, the fan comes on immediately, but I can't see the engine temp, so I am scared to drive it that way.
What else can I check before submitting to a mechanic to run diagnostics on this car and charging me the big bucks???
HELP!!
04-23-2018, 04:19 PM
#2
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04-23-2018, 05:11 PM
#3
Melting Slicks
I would first change the temp sensor then is coolant level, on my '11 GS if i don't add coolant to within an inch or less from the top of the tank it will not initiate transfer to radiator just add coolant to a higher level in the reservoir take the coolant and a funnel with you and go for a 5 or 6 blocks ride stop check coolant level add if missing do it again till it stays 3/4 full engine should not get hot any more.
If over heating persist drain a quart of coolant from rad and remove the two rear steam blocks in back of the heads and fill till starts to dribble then replace the steam blocks fill reservoir almost to the top take the gallon of coolant and funnel and go for a short 6 blocks ride check coolant level do this till it stops asking for more, you should be good and clear of overheating problems if all your cooling system is good.
There maybe 10 other ways of doing same but this way works for me every time hope it helps you.
If over heating persist drain a quart of coolant from rad and remove the two rear steam blocks in back of the heads and fill till starts to dribble then replace the steam blocks fill reservoir almost to the top take the gallon of coolant and funnel and go for a short 6 blocks ride check coolant level do this till it stops asking for more, you should be good and clear of overheating problems if all your cooling system is good.
There maybe 10 other ways of doing same but this way works for me every time hope it helps you.
04-23-2018, 05:40 PM
#4
Drifting
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make sure there is no small pieces of gravel between the shroud and the outside perimeter of the fan halo. see if you can get it to spin from underneath the bumper assembly. my ‘06 use to collect rock chips in this area and would not let the fan rotate when it was suppose to kick on. Hope this helps...
04-23-2018, 05:45 PM
#5
make sure there is no small pieces of gravel between the shroud and the outside perimeter of the fan halo. see if you can get it to spin from underneath the bumper assembly. my ‘06 use to collect rock chips in this area and would not let the fan rotate when it was suppose to kick on. Hope this helps...
The fan works. I removed the coolant temperature sensor connector, the fan comes on immediately, but still overheats. No issue with fan obstructions.
04-23-2018, 05:46 PM
#6
I would first change the temp sensor then is coolant level, on my '11 GS if i don't add coolant to within an inch or less from the top of the tank it will not initiate transfer to radiator just add coolant to a higher level in the reservoir take the coolant and a funnel with you and go for a 5 or 6 blocks ride stop check coolant level add if missing do it again till it stays 3/4 full engine should not get hot any more.
If over heating persist drain a quart of coolant from rad and remove the two rear steam blocks in back of the heads and fill till starts to dribble then replace the steam blocks fill reservoir almost to the top take the gallon of coolant and funnel and go for a short 6 blocks ride check coolant level do this till it stops asking for more, you should be good and clear of overheating problems if all your cooling system is good.
There maybe 10 other ways of doing same but this way works for me every time hope it helps you.
If over heating persist drain a quart of coolant from rad and remove the two rear steam blocks in back of the heads and fill till starts to dribble then replace the steam blocks fill reservoir almost to the top take the gallon of coolant and funnel and go for a short 6 blocks ride check coolant level do this till it stops asking for more, you should be good and clear of overheating problems if all your cooling system is good.
There maybe 10 other ways of doing same but this way works for me every time hope it helps you.
It is not a coolant issue. I have done as you suggested, and know this is not the issue. Sorry for not including this in my initial post.....but thanks!
04-23-2018, 06:53 PM
#7
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OK, you've done everything w. the cooling system, fan, etc. From what you wrote re your procedure, you've done some extensive testing PLUS you say even WITH the fan on, the car overheats. So, what do you think it is? What is your analysis of what might be wrong with the car? I'm not being corny; you seem to know a lot about your car---short of replacing parts and fluids, what else would you suggest?
04-23-2018, 07:18 PM
#8
OK, you've done everything w. the cooling system, fan, etc. From what you wrote re your procedure, you've done some extensive testing PLUS you say even WITH the fan on, the car overheats. So, what do you think it is? What is your analysis of what might be wrong with the car? I'm not being corny; you seem to know a lot about your car---short of replacing parts and fluids, what else would you suggest?
Next - take it to the Chevy dealer to let them check it out. I am out of options.....hence my post on here - - -
04-23-2018, 11:28 PM
#9
04-24-2018, 12:21 AM
#10
Le Mans Master
You said the stat opens at 180 degrees,if stock you should have a 187 and they only start to open at 187.The first thing i would do is put in a new stat.Go for a 180 stat....Good Luck.....BTW: Have you changed your coolant? If not...It is overdue.
Last edited by Cherokee Nation; 04-24-2018 at 12:25 AM. Reason: add
04-24-2018, 06:28 PM
#12
Melting Slicks
If his coolant is 50/50 it will NOT boil over until it goes to 265F or higher.
04-25-2018, 04:08 PM
#16
Had a professional garage look at my situation.
The smoking gun was the radiator cap. Who would have thought that???
It wasn't sealing off like it should. $25, and I am back on the road!
Thanks for everyone's help!!
The smoking gun was the radiator cap. Who would have thought that???
It wasn't sealing off like it should. $25, and I am back on the road!
Thanks for everyone's help!!
04-28-2018, 10:17 AM
#17
Melting Slicks
Thanks for letting us know what fixed it for every ones benefit.
04-28-2018, 10:02 PM
#18
Check the wiring connector at the fan. You jumped the wiring but as possible the fan wiring connector is burnt. Apparently the fan wiring connectors can be burnt from excessive fan use. The fan should come on . The fan not coming on is first thing I'd fixed
