74 Big Block Temperature Question
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
With a 4 core radiator and dual electric fans I had no problem keeping my vette around 160*. I would caution using the stock gauge for the correct temp. Pick up a seperate gauge or a hand held lazer temp guns from harborfrieght.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Before replacing anything you should start by getting an accurate reading. Unless there's a problem with your cooling system, you shouldn't have difficulty maintaining temp at or near your thermostat rating. That said, I wouldn't suggest a 160* stat for the street, rather a 180*
TSW
TSW
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
190-210 could be normal, depending on driving conditions. Is your car actually running hot? If not, there is no sense tearing into a cooling system which appears to be working fine.
Melting Slicks
Joined: Jul 2009
Posts: 2,091
Likes: 40
Sounds like the brass sending unit screws in the diver side head may be faulty or the clip is off , it sends a resistance reading to the temp gage that moves the needle. Its sealed and may have internal issue.
It is rare for this stuff to wear out. I never have had one fail in 32 year of owning vettes.
I would check the wire terminal and clean them , no rust or corrossion , this will change the resistance. ... make sure the terminals are tight on the head unit and at the guage.
Both parts are easy to find. Guage or sending unit. if one is malfunctioning.
I run a 180 t stat....the 74 cooling was the best ever for a BB , if everything is there (seals, all extensions, ect ect . Mine stays 180-190 on a 90 degree day ...like today it was holding 180 while I sat in road construction happy as a clam.....
When the AC worked years ago , and it was 100 outside sometimes it would approach 200 in creeping traffic.
It is rare for this stuff to wear out. I never have had one fail in 32 year of owning vettes.
I would check the wire terminal and clean them , no rust or corrossion , this will change the resistance. ... make sure the terminals are tight on the head unit and at the guage.
Both parts are easy to find. Guage or sending unit. if one is malfunctioning.
I run a 180 t stat....the 74 cooling was the best ever for a BB , if everything is there (seals, all extensions, ect ect . Mine stays 180-190 on a 90 degree day ...like today it was holding 180 while I sat in road construction happy as a clam.....
When the AC worked years ago , and it was 100 outside sometimes it would approach 200 in creeping traffic.
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Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
I agree with what everybody says about determining what temp the engine is really running. An inexpensive laser thermometer from Harbor Freight is a good start. If the running temp is "normal", say in the 160° to 210° range, depending on the thermostat, then I would suspect the sending unit is wrong for the gauge. The gauge and the sending unit must be matched for the gauge to read close to correct. If you are the original owner and know the sending unit has not been changed, then there are more tests to do to determine the cause of a gauge not being correct. Search is your friend.
If the laser thermometer indicates the engine is running too cool, then you can start to trouble shoot the cooling system.
Pete
If the laser thermometer indicates the engine is running too cool, then you can start to trouble shoot the cooling system.
Pete
Racer
Joined: Nov 2006
Posts: 490
Likes: 5
From: Tampa Bay Area, U.S.A. (Zombie Nation)
If you have an ohmmeter or other continuity checker I'd check the wire between the sender and the gauge. The lack of upward reading would occur with a broken connection I believe.
Burning Brakes
Joined: Apr 2007
Posts: 1,186
Likes: 41
From: Pinecrest FL
2015 C3 of the Year Finalist
The temp in my 69 427 never dropped below 210 once the engine was warm on a 250 mile trip last week.
I have a new 180 thermostat and a newly recored radiator with shroud seals etc.
The only thing I am missing is the piece of insulation that attaches to the front of the hood.
It didnt appear to get any hotter than 215-220 even sitting in traffic.
I have a new 180 thermostat and a newly recored radiator with shroud seals etc.
The only thing I am missing is the piece of insulation that attaches to the front of the hood.
It didnt appear to get any hotter than 215-220 even sitting in traffic.
