2007 Chevrolet Tahoe Overheating

Tiny
FKMAPLES
  • 2007 CHEVROLET TAHOE
  • 170,000 MILES

Tahoe started overheating. Replaced thermostat, water pump, flushed the radiator twice, replaced the temperature coolant sensor, and checked to make sure the heads/head gaskets were good. They checked out fine. Truck is still slightly overheating. Need more suggestions.

Do you
have the same problem?
Yes
No
Wednesday, October 9th, 2013 AT 6:19 PM

15 Replies

Tiny
MADMIKE1735
  • EXPERT
  • 960 POSTS

What size engine? 5.3? Also, have you verified flow through the radiator? You already replaced t. Stat, so next get the engine hot. (Operating temp around 215degrees) and grab the upper radiator hose. Is it hot? Next reach down and grab the lower radiator hose. (Engine off) is it hot also? If not, then your not getting flow through the radiator. I understand you tried to flush it. This doesnt always work. Let us know your results.

Was this
answer
helpful?
Yes
No
Wednesday, October 9th, 2013 AT 7:25 PM
Tiny
FKMAPLES
  • MEMBER

It's a 4.8. Will definitely check the hoses tomorrow! Thanks for the reply!

Was this
answer
helpful?
Yes
No
Wednesday, October 9th, 2013 AT 7:30 PM
Tiny
MADMIKE1735
  • EXPERT
  • 960 POSTS

No problem. I look forward to hearing back from you. Also, keep in mind this vehicle from factory with dexcool-its orange. Dont ever mix with green, as it will clump up, and clog everything.

Was this
answer
helpful?
Yes
No
+2
Wednesday, October 9th, 2013 AT 7:48 PM
Tiny
FKMAPLES
  • MEMBER

Checked both hoses this morning. Flow is good. Not sure at this point what else it could be. Any more suggestions?

Was this
answer
helpful?
Yes
No
-1
Thursday, October 10th, 2013 AT 6:26 AM
Tiny
MADMIKE1735
  • EXPERT
  • 960 POSTS

How long does it take for it to start to overheat? And does it overheat at idle, or when your driving? You verified flow through the radiator, my next guess is that its airbound. When you turn the heat on, does it blow hot air from the vents?

Was this
answer
helpful?
Yes
No
-1
Saturday, October 12th, 2013 AT 2:56 PM
Tiny
FKMAPLES
  • MEMBER

Sometimes it overheats at idle and sometimes it does not! The heat does not blow hot when turned on. We are thinking there is air in the system. Does this sound the same to you. If so, what is the best way to get the air out?

Was this
answer
helpful?
Yes
No
Saturday, October 12th, 2013 AT 3:07 PM
Tiny
MADMIKE1735
  • EXPERT
  • 960 POSTS

No heat from vent verifies my suspicion. It is air bound. Let me check to see if this engine has an air bleed screw. I dont think it does, but im going to double check. Have you checked the coolant level after you initially filled it up? Also, does your radiator have a cap, or do you fill your vehicle through the overflow tank?

Was this
answer
helpful?
Yes
No
Saturday, October 12th, 2013 AT 3:10 PM
Tiny
FKMAPLES
  • MEMBER

After initially filling it up it settles and the coolant is a little lower but not empty and the truck does not have a radiator cap. We looked for an air bleed screw and either the truck does not have one or we did not find it.

Was this
answer
helpful?
Yes
No
Saturday, October 12th, 2013 AT 3:13 PM
Tiny
MADMIKE1735
  • EXPERT
  • 960 POSTS

Ok, your engine does have an air bleed nipple. However the picture im looking at isnt very clear. Its shows it should be near your oil fill cap on a coolant hose located towards the front of the engine, on the passenger side. Check it out. If you find it, what your going to do is fill the cooling system with the engine off. Open bleeder. When coolant comes out, without anymore air bubbles, shut the bleeder. Top off the system. You may need to get the engine up to running temp, then let it cool off and repeat this procedure.

Was this
answer
helpful?
Yes
No
Saturday, October 12th, 2013 AT 3:14 PM
Tiny
FKMAPLES
  • MEMBER

Ok. We are going to look again. If its not on this truck, what do you suggest to get the air out?

Was this
answer
helpful?
Yes
No
Saturday, October 12th, 2013 AT 3:18 PM
Tiny
MADMIKE1735
  • EXPERT
  • 960 POSTS

Last resort would be to pressure fill the system, but only a properly equipped garage can do that. Im not sure if there are 1 or 2 bleeders, as I said, this picture is very unclear.

Was this
answer
helpful?
Yes
No
-1
Saturday, October 12th, 2013 AT 3:19 PM
Tiny
FKMAPLES
  • MEMBER

Thank you SO much for your help. We are going to try this and I will get back with you. Hopefully with good news!

Was this
answer
helpful?
Yes
No
Saturday, October 12th, 2013 AT 3:22 PM
Tiny
MADMIKE1735
  • EXPERT
  • 960 POSTS

No problem. Im looking forward to good news!

Was this
answer
helpful?
Yes
No
Saturday, October 12th, 2013 AT 3:28 PM
Tiny
NICOLE GRAHAM
  • MEMBER

I have the same exact issue with my 2005 tahoe 4.8 I have done everything from replacing the radiator to the ect sensor and to the cap. I also pressure filled the system to ensure there was no air in the system but still I'm having the same overheating issue with a constant shut down when the truck gets hot. Please help!

Was this
answer
helpful?
Yes
No
Thursday, July 28th, 2016 AT 4:51 AM
Tiny
FKMAPLES
  • MEMBER

@ Nicole Graham. It ended up being a slow leak at the quick disconnects to the rear air that became a pretty steady leak. We replaced numerous things, had compression tests done, etc. No one including us could find anything. It ended up being those disconnects. We replaced them (a $25 part) and it immediately stopped.

Was this
answer
helpful?
Yes
No
+2
Thursday, July 28th, 2016 AT 4:57 AM

Please login or register to post a reply.

Recommended Guides