conversion cooling problem has us stumped
Thread Starter
Teching In
Joined: Aug 2008
Posts: 1
Likes: 0
From: Topanga, CA
conversion cooling problem has us stumped Hi, all,
Fairly new here, so forgive me if this is a dumb or already-answered-to-death question:
'67 C10 short/fleet LS6 conversion, just on the road. Runs great, but pegs the (Stewart-Warner) temp gauge at about 220 degrees pretty quickly. Heat gun shows 180 degrees at the thermostat housing (running a 180 thermostat). Giant Nascar four-row Superspeedway radiator, so no cooling issues there; twin fans, too. New Edelbrock water pump, as well.
Here's all I can figure: system isn't properly bled; so the temp gauge sender is reading hot air rather than coolant; or temp gauge sender itself is too large (had to run an adaptor in the cylinder head) to fit the hole and is contacting metal directly.
Any thoughts? Your help would be much appreciated.
Thanks,
David Langness
Fairly new here, so forgive me if this is a dumb or already-answered-to-death question:
'67 C10 short/fleet LS6 conversion, just on the road. Runs great, but pegs the (Stewart-Warner) temp gauge at about 220 degrees pretty quickly. Heat gun shows 180 degrees at the thermostat housing (running a 180 thermostat). Giant Nascar four-row Superspeedway radiator, so no cooling issues there; twin fans, too. New Edelbrock water pump, as well.
Here's all I can figure: system isn't properly bled; so the temp gauge sender is reading hot air rather than coolant; or temp gauge sender itself is too large (had to run an adaptor in the cylinder head) to fit the hole and is contacting metal directly.
Any thoughts? Your help would be much appreciated.
Thanks,
David Langness
Teching In
Joined: Jan 2011
Posts: 19
Likes: 0
From: Fort Worth, Texas
Your probably on the right track, you might have air in the system. Try aiming the truck up hill, disconnect the small vent hose, and add coolant through the upper radiator hose until all air escapes thru the vent hose(some call this the steam line)and solid coolant comes out. This tip came from the ls1 truck forum and has helped many. Hope it helps.
Its a long shot but I had this happen to me. When I did my 240SX conversion my radiator was a cross-flow built for the LS swap. My engine wouldn't cool. We eventually figured out that the manufacturer didn't put the divider in the end tank so the coolant was just flowing from the top hose to the bottom without going through the radiator.
Did you fill it through the upper hose? If you take the upper hose off and hold it up, you can fill the engine easier. Just pour the coolant in it until the hose is full. Usually just filling the radiator isn't enough and will cause air problems.
Staging Lane
Joined: Jul 2012
Posts: 84
Likes: 0
From: Bakersfield, CA
#1 is your temp gauge mechanical or electric?
If electric:
use a infrared to measure the temperature of the head at the point at which the temp sender is in the head. Remember shiny surfaces will trick an infrared thermometer. If the actual temperature is reasonable vs the gauge then you have either a temp sender with an inappropriate resistance range for the gauge OR you have a ground issue. If there is a different ground potential at the engine block vs the gauge your readings will be false. I usually ground the instruments tot he engine block with a 12 or 14 gauge ground wire in addition to the battery ground to the block or even better tot he starter.
If mechanical:
There is a reading issue with the gauge. Boil water in a pan and immerse the sender in it. Use a known thermometer to measure the water temp and check that vs what the mechanical gauge reads. I hope this helps.
If electric:
use a infrared to measure the temperature of the head at the point at which the temp sender is in the head. Remember shiny surfaces will trick an infrared thermometer. If the actual temperature is reasonable vs the gauge then you have either a temp sender with an inappropriate resistance range for the gauge OR you have a ground issue. If there is a different ground potential at the engine block vs the gauge your readings will be false. I usually ground the instruments tot he engine block with a 12 or 14 gauge ground wire in addition to the battery ground to the block or even better tot he starter.
If mechanical:
There is a reading issue with the gauge. Boil water in a pan and immerse the sender in it. Use a known thermometer to measure the water temp and check that vs what the mechanical gauge reads. I hope this helps.
Trending Topics
W/ the sensor riding on the head material, it may well be reporting the temp of the head, and not the water flowing thru it. The head is hotter than the water flowing thru it........
Fans wired backward?
Fans wired backward?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Jack up the front end of the car to get the radiator the highest point, then pull the steam vents off until coolant comes out there. That will get all the air out. Shouldn't need to pull a radiator hose that way.
gauge I know of a couple of suppliers who have STOPPED selling the new Stewart_Warner gauges because of faulty products, you might check your gauge, but most of the suggestions are certainly on the right track...You will get it figured out, all good stuff takes time...