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Recently I changed out my water pump, with an aftermarket one, and done the coolant procedure, and used dexcool, also got a new surge cap. I know its hot here in fla 100 degrees out, but street driving temps reading 215-220 should I be concerned? Are these normal temps? Its like driving doing 50mph on a long stretch roadway and only cools off like 2 degrees at a time , whereas when I had an ac delco water pump I thought it went down 3-4 degrees at a time. oh and A/C is off because it doen't work. Any thoughts Thanks
Last edited by corvet786c; Jul 1, 2020 at 02:28 PM.
No concerns in that high of heat I will see 230-235 steadily in that heat whenever it’s 95-106 lol. . It’s really not me to be driven daily like that from my opinion only . Make sure u diluted 50/50 or at least close to it . Run it at night when it’s cool or early morning and see what ya get .
Last edited by Speedy007; Jul 1, 2020 at 02:26 PM.
I raised the front of the vehicle and let the car warm up to 194 degress and put the cap back on. Yesterday the climate readings were 100 outside and my coolant readings were 215 with no a/c.
I 'll try to do a better job blowing out the radiator again and see if that will help even more, Also I noticed the hoses collapsed looked like they were sucked in when cold, not so now? Not sure if this makes a difference.
Last edited by corvet786c; Jul 2, 2020 at 04:23 AM.
The rad low fan comes on automatically when AC is on so it may run cooler. Saccity has a coolit mod you can install in 5 min that allows you to turn on rad fan with a fob anytime. This may be an option if all your mechanical systems are functioning as they should. I had one on my 01 worked great.
I just put the saccity unit in my car. it runs the high fan and works great. I actually went there to buy it and the guy hooked it up for me
they are one of the vendors on this site
I live in NC, and in the 90s and 100s it stays at 195-198. Parked it will hit 225 as designed when the fans come on it cools right off. If your temps after the water pump are noticeably higher than pre-water pump, I would be verifying why. Stock temp t-stat, stock fan settings in my car.
Last edited by Ed Ramberger; Jul 2, 2020 at 09:33 PM.
I live in NC, and in the 90s and 100s it stays at 195-198. Parked it will hit 225 as designed when the fans come on it cools right off. If your temps after the water pump are noticeably higher than pre-water pump, I would be verifying why. Stock temp t-stat, stock fan settings in my car.
Yeah I cleaned the radiator today and went down 2 degrees according to DIC (212 F) I also forgot to add .5 above the full line, not sure if this will help or not. My main concern is if it gets to 220 -225 degrees in traffic it needs to cool down rapidly to like 205 and does not, its slower.
I checked and my both fans are working and I installed a new 18psi cap.
Last edited by corvet786c; Jul 2, 2020 at 09:53 PM.
The most common scenario I see is that a C5 owner opens the cooling system for some reason, like you changing the water pump, and then coolant temperatures are higher than before, sometimes much higher.
Often but not always, higher coolant temperatures after opening the cooling system are because all the air was not removed from the heads. The Factory Service Manual has a procedure for that is designed to get the air out. Note the part about cycling up to 3,000 RPM and back down.
There are other things that can be done if the FSM procedure does not work. Try it first and then post your results.
The most common scenario I see is that a C5 owner opens the cooling system for some reason, like you changing the water pump, and then coolant temperatures are higher than before, sometimes much higher.
Often but not always, higher coolant temperatures after opening the cooling system are because all the air was not removed from the heads. The Factory Service Manual has a procedure for that is designed to get the air out. Note the part about cycling up to 3,000 RPM and back down.
There are other things that can be done if the FSM procedure does not work. Try it first and then post your results.
I'll try the procedure again this weekend. And see what happens.
I live in DFW & have been battling this issue, the summer months aren't helping either. Last month I installed a new water pump, replaced coolant hoses, flushed & cleaned the radiator, even cleaned all the debris in-between the radiator & condenser, & evac & recharge the A/C.
It was still running hot around 225. Took it to Gspeed this week & had the cooling fans replaced, it still running as hot as 207 to 232 & the fans aren't coming on.
UPdate, I researched this topic and found out that sometimes the GM procedure does not work or may take a few times to get the air out.
There is a cross bar between the cylinder heads, I just loosed the passenger side and guess what air hissed out, a good amount to. I did it for both passenger and driver side, when the coolant comes out just tighten the bolt back up.
I test drove the car and the temps came down about 5 degrees, When I parked the car I unloosed the bolts again and more air came out. Some forum members had success doing this. I take a picture of it.
Air gets trapped in the cylinder head passages, this relieves it.
Last edited by corvet786c; Jul 3, 2020 at 05:07 PM.
Yes that procedure will get air out of the heads if the FSM method does not work, but maybe not all the air, as you have seen after parking an rechecking.
Any time I open the cooling system on my car, I do the following to get ALL the air out:
First make sure the surge tank is full, then disconnect the coolant air bleed line which comes from the throttle body to the radiator, capping the radiator outlet with a piece of hose bent over and clamped and clamped on the radiator outlet. Extend the hose which is attached to the throttle body to a gallon container on the floor by the passenger side fender.
Start up and watch what comes out of the hose from the throttle body into the container on the floor as the cooling system attempts to come up to pressure during warm up. Do not let the surge tank get low. Stop and refill from the container on the floor before the surge tank gets low.
Usually more than a QUART of coolant along with air bubbles is ejected into the container on the floor before bubbles stop. When bubbles stop, the air is OUT.
Reconnect the air bleed hose to the radiator and refill the surge tank from the container on the floor.
The coolant air bleed line is connected to the passenger side of the radiator, the left, or smaller (1/4" ID) in this picture:
It would have been easiest to fill it with the head drain plug out. Then re insert full it until the steam line was over flowing out the Tb . Start it run it and all air whatever minute amount that’s left would purge into the tank . It’s the way I did mine .
But now I have no steam vent line to deal with or coolant through the throttle body so in the future it will be drain plug only . One could get creative and put a bleeder valve on the steam vent lol .
Last edited by Speedy007; Jul 3, 2020 at 09:52 PM.
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
Originally Posted by TXWMH
I live in DFW & have been battling this issue, the summer months aren't helping either. Last month I installed a new water pump, replaced coolant hoses, flushed & cleaned the radiator, even cleaned all the debris in-between the radiator & condenser, & evac & recharge the A/C.
It was still running hot around 225. Took it to Gspeed this week & had the cooling fans replaced, it still running as hot as 207 to 232 & the fans aren't coming on.
these cars come from the factory set to run at those temps, if you want it to run cooler you need to have the fan settings adjusted in the tune, otherwise you could replace the entire cooling system with brand new parts and be in the same boat you're in right now
these cars come from the factory set to run at those temps, if you want it to run cooler you need to have the fan settings adjusted in the tune, otherwise you could replace the entire cooling system with brand new parts and be in the same boat you're in right now
I don't think the temps you are seeing are that high if the outside temps are 100 degrees. You quoted 215-220, I would not be worried at all. If you are, get the fans adjusted to come on earlier. Any tuner should be able to do this. I believe the factory setting for high speed is 236 degrees so the LS1 or LS6 can easily run 220 degrees. Like others mentioned, you can also get a Sac City Corvette Cool-it. I ran one on my supercharged 383 in my 98 C5 as she loved to get hot in stop and go traffic. They are currently running a ONE day sale on it.
Is that some sorta relay to overclock the fans ? I would t be getting into over clocking my fan motors or messing around with fan adjustments in the pcm if you absolutely don’t know 100% on what your doing.
Using ECS mail order tune (controls fans), a 160 T-Stat, flushed coolant multiple times (distilled water and dexcool), externally cleaned radiator and condenser w/water hose, and a properly burped system my 04 Z06 runs between 165 and I've seen it as high 186 (in 94F ambient temp)
Just finished a 1330 mile road trip and the avg coolant temp was 174-ish. Oil temp avg was about 185-ish
High Coolant Temps
I don't think the temps you are seeing are that high if the outside temps are 100 degrees. You quoted 215-220, I would not be worried at all. If you are, get the fans adjusted to come on earlier. Any tuner should be able to do this. I believe the factory setting for high speed is 236 degrees so the LS1 or LS6 can easily run 220 degrees. Like others mentioned, you can also get a Sac City Corvette Cool-it. I ran one on my supercharged 383 in my 98 C5 as she loved to get hot in stop and go traffic. They are currently running a ONE day sale on it.
