Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks



Visit the new site at vcca.org

Previous Thread
Next Thread
Print Thread
Rate Thread
#233626 02/07/12 10:05 PM
Joined: Jan 2012
Posts: 137
Shade Tree Mechanic
OP Offline
Shade Tree Mechanic
Joined: Jan 2012
Posts: 137
howdy all
i have a 1989 corvette that is getting hot according to the guage.it also must have a safty that also shuts the engine down when it gets too hot because the engine shuts off.
the guage will show 296 degrees and it shuts down.
it doesn't seem that hot to touch the valve covers.
it also does not boil over the radiator hoses feel cold to touch.i put a new thermostat in it and a new radiator cap because it's center rivit had come out leaveing a small hole in center of cap.all belts are good and turning.this is stumping me .anyone know whats wrong here??

thank you
jeff korner
southeast indiana

World's Greatest
 
Vintage Chevrolet Club of America
"The World's Best Chevrolet Club"
Joined: Aug 2006
Posts: 1,774
Likes: 4
ChatMaster - 1,500
Offline
ChatMaster - 1,500
Joined: Aug 2006
Posts: 1,774
Likes: 4
Jeff,
I don't know much about vetts, but if the hoses are cold it sounds like the coolant is not circulating. Could you have a collapsed hose or bad water pump?


Ed
Joined: Jan 2012
Posts: 137
Shade Tree Mechanic
OP Offline
Shade Tree Mechanic
Joined: Jan 2012
Posts: 137
howdy ed
hoses seem fine and the only way i have seen water pumps go bad on other vehicals i have had is that they start leaking externaly. this has really got me puzzled. it's almost like the impeller is broken inside the pump.i'm not sure it's even over heated,the gage says so but the engine seems ok.

jeff

Joined: Nov 2001
Posts: 29,863
Tech Advisor
ChatMaster - 25,000
Offline
Tech Advisor
ChatMaster - 25,000
Joined: Nov 2001
Posts: 29,863
Quote
if the hoses are cold it sounds like the coolant is not circulating.


Have you looked in the radiator with the engine running to see if the coolant is circulating properly??

laugh wink beer2


The Mangy Old Mutt

"If It's Not Junk.....It's Not Treasure!"
Joined: Nov 2001
Posts: 5,906
Likes: 8
Former ChatMaster
ChatMaster - 5,000
Offline
Former ChatMaster
ChatMaster - 5,000
Joined: Nov 2001
Posts: 5,906
Likes: 8
I was going to suggest the same thing. Start the car cold, with radiator cap OFF, stick your finger in the water. See how long it takes before it gets really hot.

Joined: Jan 2012
Posts: 137
Shade Tree Mechanic
OP Offline
Shade Tree Mechanic
Joined: Jan 2012
Posts: 137
howdy dog
the coolant is not circulateing, new thermistat, hoses are cold, gage says 296 degrees which is 84 degrees over boiling
something should be seeming hot.i think gage is wrong and sencor or something is shuting engine down.these newer cars with this computer junk stinks.

jeff

Joined: Nov 2001
Posts: 29,863
Tech Advisor
ChatMaster - 25,000
Offline
Tech Advisor
ChatMaster - 25,000
Joined: Nov 2001
Posts: 29,863
If your coolant is not circulating then that is why your engine is overheating. Definitely sounds like you have a water pump problem or a possible blockage in the cooling system.

laugh wink beer2


The Mangy Old Mutt

"If It's Not Junk.....It's Not Treasure!"
Joined: Dec 2001
Posts: 10,379
Likes: 1
Technical Advisor
ChatMaster - 10,000
Offline
Technical Advisor
ChatMaster - 10,000
Joined: Dec 2001
Posts: 10,379
Likes: 1



Based on your description, I would suspect the gauge.


devil Agrin


RAY


Chevradioman
http://www.vccacolumbiariverregion.org/



1925 Superior K Roadster
1928 Convertible, Sport, Cabriolet
1933 Eagle, Coupe
1941 Master Deluxe 5-Passenger Coupe
1950 Styleline Deluxe 4-Door Sedan
1950 Styleline Deluxe Convertible
2002 Pontiac, Montana, Passenger Van
2014 Impala, 4-Door Sedan, White Diamond, LTZ
2017 Silverado, Double Cab, Z71, 4X4, White, Standard Bed, LTZ

If you need a shoulder to cry on, pull off to the side of the road.
Death is the number 1 killer in the world.


Joined: Dec 2010
Posts: 799
ChatMaster - 750
Offline
ChatMaster - 750
Joined: Dec 2010
Posts: 799
You must have water circulation.....pull the pump..pull the radiator...forget the sensor, it's working...New engines about 7000.00


Old cars have always owned me.
Joined: Jan 2008
Posts: 828
Likes: 6
ChatMaster - 750
Offline
ChatMaster - 750
Joined: Jan 2008
Posts: 828
Likes: 6
If it was getting that hot it would puke it out the overflow or the radiator if the cap is off, when you shut the engine off. How long does it take for the gauge to read that, and will it do it at idle or do you have to drive it?
I am not sure if that year uses the same coolant sensor for the computer and gauge but I would want to use a scan tool to see what the computer is seeing. Cold the Intake air temp sensor and coolant temp sensor should read
within a few degrees of each other.
Another check you can do is turn the heater on high and see if it takes longer for the temp to rise.
In all my years in the shop I do not remember ever seeing a small block water pump impeller come lose.
Was any engine work done prior to this problem?
A wire to the sensor that may be going to ground as it heats will cause the gauge to read hot.

Last edited by dens41; 02/23/12 09:29 PM.

Dens Chevys 1927 Speedster 1928 coupe 1941street rod 1947Fleetline 4 door 1949 1/2 ton Pickup (sold) 1954 210 4 door 1972 Monte Carlo 2003 Corvette convt..
Joined: Dec 2001
Posts: 279
Backyard Mechanic
Offline
Backyard Mechanic
Joined: Dec 2001
Posts: 279
Their is a specific procedure to change the thermostat/replace coolant in these models.

The front must be jacked up approx one foot off the ground, otherwise the cooling system WILL BE air bound.

I would start with burping the cooling system, and then verify the proper operation of the temperature gauge. If the sensor is in an air pocket - it will not function properly.

296!? What was the oil temperature?
I won't get alarmed until I read that as well.....


Oliver J. Giorgi
Technical Advisor
1958 Passenger Car
Joined: Jul 2006
Posts: 388
Backyard Mechanic
Offline
Backyard Mechanic
Joined: Jul 2006
Posts: 388
Jeff,
Until you actually shoot the engine and radiator with a temp gun you are not going to get much accomplished.Hit the gun on the thermo housing,upper hose at radiator mid radiator then lower hose.

Is it at all poss you have the thermo installed upside down??

Also,a temp sensor going bad will send false signal to ECM,which controls the temp guage and safety. Hope this helps,Jim

Originally Posted by jeffkorner
howdy all
i have a 1989 corvette that is getting hot according to the guage.it also must have a safty that also shuts the engine down when it gets too hot because the engine shuts off.
the guage will show 296 degrees and it shuts down.
it doesn't seem that hot to touch the valve covers.
it also does not boil over the radiator hoses feel cold to touch.i put a new thermostat in it and a new radiator cap because it's center rivit had come out leaveing a small hole in center of cap.all belts are good and turning.this is stumping me .anyone know whats wrong here??

thank you
jeff korner
southeast indiana


Link Copied to Clipboard
 

Notice: Any comments posted herein do not necessarily reflect the official position of the VCCA.

Powered by UBB.threads™ PHP Forum Software 7.7.5