General Discussion Discuss your Oldsmobile or other car-related topics.

Failed thermostat

Thread Tools
 
Search this Thread
 
Old December 17th, 2019, 05:19 AM
  #1  
Registered User
Thread Starter
 
Will22's Avatar
 
Join Date: Apr 2017
Location: Northeast Florida
Posts: 353
Failed thermostat

Long story short, I replaced radiator hoses, thermostat and antifreeze last year. My car is a 1972 Cutlass Supreme Convertible with the original 350 Rocket, all stock. The thermostat was a 180 degree Mr Gasket High Performance. Last week we had a break in the weather ambient temperature was around 55 degrees) so I took the car out for a drive. On the way home I noticed steam coming out of the hood while running down the highway. I looked down and the Hot light was on (very dim). I pulled over and opened the hood. The car was very hot, boiling over. I trailered the car home and after it cooled down, found the thermostat stuck closed. I replaced the thermostat with a 180 degree ACDelco Professional and changed the oil and filter (since it was close to being due). As hot as the car got, I was concerned about the head gasket so I did a block test and it did not show any signs of combustion gas. There is no sign of water in the oil or oil in the antifreeze. The car is running fine, no white smoke out of the exhaust. Is there anything else I should check? Hopefully I just got lucky!

TIA
Will
Will22 is offline  
Old December 17th, 2019, 05:34 AM
  #2  
CH3NO2 LEARN IT BURN IT
 
droldsmorland's Avatar
 
Join Date: Jul 2010
Location: Land of Taxes
Posts: 4,921
Same thing happened to me on a secondary road. Boil over and started bucking at a stop sign. Looked down at the temp yikes 230!. Shut it off cooled it down added water from a friendly guy on the corner and took it home. Replaced the T Stat with a 192* HD Stant and a full flush n fill with premix.

You are probably OK and caught it before any damage was done. These engines are tough. Do flush n fill on the coolant if you didn't already? That should be done every 2,3,4 years.
droldsmorland is offline  
Old December 17th, 2019, 05:36 AM
  #3  
Moderator
 
Olds64's Avatar
 
Join Date: Jul 2007
Location: Edmond, OK
Posts: 16,109
These kits are handy to flush the cooling system.

https://www.amazon.com/Dorman-47016-Coolant-Service-Kit/dp/B000DCO58S/ref=sr_1_8?keywords=radiator+flush+kit&qid=1576589771&sr=8-8 https://www.amazon.com/Dorman-47016-Coolant-Service-Kit/dp/B000DCO58S/ref=sr_1_8?keywords=radiator+flush+kit&qid=1576589771&sr=8-8
Olds64 is offline  
Old December 17th, 2019, 06:29 AM
  #4  
Registered User
 
oddball's Avatar
 
Join Date: Sep 2011
Location: Plano, TX
Posts: 1,864
Don't sweat it. My mom regularly overheated the 350 on a daily basis in the 80's and it kept chugging. It takes quite a bit to distort these suckers.

I would recommend adding a cheap temp and oil pressure gauge temporarily while settling down the new engine.
oddball is offline  
Old December 17th, 2019, 06:41 AM
  #5  
Registered User
Thread Starter
 
Will22's Avatar
 
Join Date: Apr 2017
Location: Northeast Florida
Posts: 353
Thanks guys. I did do a flush on the coolant system. I am going to keep on driving it and hope all is good!
Will22 is offline  
Old December 17th, 2019, 07:18 AM
  #6  
CH3NO2 LEARN IT BURN IT
 
droldsmorland's Avatar
 
Join Date: Jul 2010
Location: Land of Taxes
Posts: 4,921
Yes, a nice set of Stewart/Warner gauges is a must. Did this in 1986.I've since replaced the oil line as it got brittle.

droldsmorland is offline  
Old December 17th, 2019, 07:51 AM
  #7  
Old(s) Fart
 
joe_padavano's Avatar
 
Join Date: Mar 2007
Location: Northern VA
Posts: 47,619
Cast iron motors are a lot less sensitive to a short-duration overheating. I've done this more than once on an Olds motor over the last 45 years, and never had a problem once the original overheating cause was repaired.
joe_padavano is online now  
Old December 17th, 2019, 11:29 AM
  #8  
Registered User
Thread Starter
 
Will22's Avatar
 
Join Date: Apr 2017
Location: Northeast Florida
Posts: 353
Originally Posted by joe_padavano
Cast iron motors are a lot less sensitive to a short-duration overheating. I've done this more than once on an Olds motor over the last 45 years, and never had a problem once the original overheating cause was repaired.
Thank Joe. I appreciate the response.
Will22 is offline  
Old December 17th, 2019, 05:25 PM
  #9  
Registered User
 
Schurkey's Avatar
 
Join Date: Feb 2019
Location: The Seasonally-Frozen Wastelands
Posts: 660
Originally Posted by droldsmorland
Same thing happened to me on a secondary road. Boil over and started bucking at a stop sign. Looked down at the temp yikes 230!.
230 is NOTHING. The sensor for the "HOT" light probably doesn't close until 240--265 F.
Schurkey is offline  
Old December 17th, 2019, 06:13 PM
  #10  
CH3NO2 LEARN IT BURN IT
 
droldsmorland's Avatar
 
Join Date: Jul 2010
Location: Land of Taxes
Posts: 4,921
ya now that I looked at the picture I posted that needle was at the 4 o'clock position so ya 260.
droldsmorland is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
SanTan Devil
The Newbie Forum
19
May 13th, 2019 06:51 PM
Obop
Small Blocks
7
September 1st, 2017 02:16 PM
Double D Farms
Small Blocks
12
July 30th, 2014 06:40 AM
spyke
General Discussion
9
March 10th, 2014 06:08 AM
EightyEightCut
Small Blocks
11
April 28th, 2013 08:27 PM



Quick Reply: Failed thermostat



All times are GMT -7. The time now is 12:22 PM.