Coolant/Temp question..
Thread Starter
Drifting
Joined: Jul 2003
Posts: 1,535
Likes: 0
From: Somewhere in Michigan, with a cold beer in my hand
Coolant/Temp question..
Its a 96 LT4---When i have the car in 4th gear going 70 the coolant reads 197....when i shift to 5th the coolant reads 204...when i shift to 6th the coolant goes to 210.....why?
Radiator is free of debris, no leaves or bags under there, no leaks.....I would appreciate any thoughts or remedies.
Thanks
Radiator is free of debris, no leaves or bags under there, no leaks.....I would appreciate any thoughts or remedies.
Thanks
Le Mans Master
Joined: Mar 2002
Posts: 5,889
Likes: 2
From: Castro Valley Calif.
St. Jude Donor '03 thru '26
Re: Coolant/Temp question.. (fryguy84)
I'll bet it has to do with the RPMs of your motor pushing the water pump. Try clutching it and run up the same RPMs as a lower gear while in 6th (but coasting) and see what happens..... :confused:
Elite Torch Red Member
Joined: Sep 1999
Posts: 57,805
Likes: 23
From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
Cental/South NJ Events Coordinator
CI 1-2-3-4-5-6-7-8-9-10-11-12 Vet
CI-II Burnout & Drag Champ
St. Jude Donor '03-'04-'05-'06-'07
Re: Coolant/Temp question.. (Caboboy)
I'll bet it has to do with the RPMs of your motor pushing the water pump.
It happens to me all the time.
Burning Brakes
Joined: Dec 2003
Posts: 770
Likes: 0
From: Madison Mississippi
Re: Coolant/Temp question.. (fryguy84)
Good, gradual change would mean you might want to check your air bleed screw and burp it. Mine did something similar and would float up and down depending on the rpms and/or gear. I bet you have a little air pocket. Try this, turn on the heater and start up the engine. Then bleed the air valve by opening the valve, squeezing the hose a bit until the fluid dribbles out then close off the valve. Run it for a couple minutes then repeat. You should get more constant coolant temps. Let us know what you find. :smash:
Elite Torch Red Member
Joined: Sep 1999
Posts: 57,805
Likes: 23
From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
Cental/South NJ Events Coordinator
CI 1-2-3-4-5-6-7-8-9-10-11-12 Vet
CI-II Burnout & Drag Champ
St. Jude Donor '03-'04-'05-'06-'07
Re: Coolant/Temp question.. (RUBYREDVETTECARD)
When I burped my system, took almost two hours.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Thread Starter
Drifting
Joined: Jul 2003
Posts: 1,535
Likes: 0
From: Somewhere in Michigan, with a cold beer in my hand
Re: Coolant/Temp question.. (Mr Mojo)
When I burped my system, took almost two hours.
how do you know when its fully burped?
Burning Brakes
Joined: Dec 2003
Posts: 770
Likes: 0
From: Madison Mississippi
Re: Coolant/Temp question.. (fryguy84)
Not exactly,
the heat on ensures the coolant flows through the heater core which in a lot of cases is a good place to have air in the system. Burp it and close the valve off. Then repeat after you run it for a while to let the thermostat cycle the coolant around and once you do it a couple times you get most of it out. Drive it for a few days and do it again and you should have all of the air out. The corvette is difficult to burp complete the first try. most cars are easy. A little air is no big deal it, it does make your temps swing more than normal though. Hope that clears it up for you. :auto:
the heat on ensures the coolant flows through the heater core which in a lot of cases is a good place to have air in the system. Burp it and close the valve off. Then repeat after you run it for a while to let the thermostat cycle the coolant around and once you do it a couple times you get most of it out. Drive it for a few days and do it again and you should have all of the air out. The corvette is difficult to burp complete the first try. most cars are easy. A little air is no big deal it, it does make your temps swing more than normal though. Hope that clears it up for you. :auto:
Burning Brakes
Joined: Feb 2000
Posts: 824
Likes: 2
From: Camden SC
Re: Coolant/Temp question.. (RUBYREDVETTECARD)
Assuming the same forward speed, the variable is clearly engine rpm and associated reduced flow rate provided by the water pump. Since the variation is around 6% and temps are still within acceptable range, no problem.
Keep the greasy side down.
dlmeyers 90 coupe zf6 3 speed shocks
Keep the greasy side down.
dlmeyers 90 coupe zf6 3 speed shocks
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Coolant/Temp question.. (fryguy84)
Hmm. I don't remember my car doing that with the OEM water pump but it would make sense.
With my electric water pump I see just the opposite. Higher RPM's mean slightly higher temps since the water pump is pumping at the same rate all the time.
With my electric water pump I see just the opposite. Higher RPM's mean slightly higher temps since the water pump is pumping at the same rate all the time.
Drifting
Joined: Oct 1999
Posts: 1,722
Likes: 0
From: Gloucester Va
Re: Coolant/Temp question.. (Nathan Plemons)
COuld it be a combo of RPM, and work. Wouldn't the car be under more of a load with it in 6th gear/lower RPM but still trying to maintain say 60MPH.
Le Mans Master
Joined: Oct 2002
Posts: 7,178
Likes: 1
From: Bahston Mass.
Re: Coolant/Temp question.. (jfb)
Your temperature rises because the coolant flow drops with dropping engine rpm.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: Coolant/Temp question.. (JB666)
The air flow is the same........only the waterpump slows down because you maintain the same highway speed and shift into 5th then 6th. Even if you increase your highway speed, you make a larger percent drop in rpm in 5th & 6th than you increase the air flow by driving faster. You need a higher flow waterpump or a larger radiator, or both.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
Re: Coolant/Temp question.. (jfb)
JFB is correct. Except:
Your temps aren't too high as they are. I don't think you need any of these. If you are concerned, pull your radiator out and clean out all the leaves, twigs and plastic bags that have built up between the rad and condensor. If you're still not happy, pour in a container of Water Wetter.
RACE ON!!!
You need a higher flow waterpump or a larger radiator, or both.
RACE ON!!!
Burning Brakes
Joined: Jul 2001
Posts: 902
Likes: 0
From: Glen Allen, VA
CI 3-4-6-8-9 Veteran
Re: Coolant/Temp question.. (fryguy84)
Mine does about the same on my '94. I was hoping a new water pump (OEM) I installed last week would fix it, but it doesn't. I'm looking at either replacing the radiator with a beefier aftermarket one or just getting a brand new one (with no bent fins :lol: ). I know it's the nature of the beast for these to run hot, but I'd prefer to do whatever to keep it down.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 32
From: The Top of Utah
Re: Coolant/Temp question.. (TimC)
If the temp is the only reason you're replacing the water pump...Don't. As long as the pump is turning, it's pumping. Pump bearings wear out, seals leak, but they don't diminish in capacity with age. See my suggestion, above if you feel you need some relief.
RACE ON!!!
RACE ON!!!
Burning Brakes
Joined: Jul 2001
Posts: 902
Likes: 0
From: Glen Allen, VA
CI 3-4-6-8-9 Veteran
Re: Coolant/Temp question.. (CFI-EFI)
If the temp is the only reason you're replacing the water pump...Don't. As long as the pump is turning, it's pumping. Pump bearings wear out, seals leak, but they don't diminish in capacity with age. See my suggestion, above if you feel you need some relief.
RACE ON!!!
RACE ON!!!