Overheats idle, temp drops in throttle
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11 Second Club
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Joined: Mar 2007
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From: Windsor, Ontario Canada
Overheats idle, temp drops in throttle I had this issues last season with my LS Swap. I figured maybe the stock ran and crappy single fan with no shroud was the issue. So over the winter I switched to a Griffen dual pass and twin 12" 3400cfm fans.
Rundown on the car.
160* stat
4 port steam port routed to the top of the water pump (above the upper rad hose)
Fans kick on around 175.
Now I have bled the cooling system multiple times and ways. Pulled the steam tube off multiple times until all air is out, jacked the front up and used a funnel screwed into the rad filled with coolant etc.
The car still wants to overheat idle. It will get up to 220*, as soon as a blip the throttle it drops, if I continue to rev it say 1200+rpm it will drop down into the 160* range.
It seems to only happen once and then the car is fine.
I take it to work in the morning, as soon as I hit the drivethru (1min drive) the car gets up to around 210 degrees in literally 1 minute. As soon as I start driving it drops down to 160s in like 15 seconds. Then generally it is fine the rest of the time im driving, doesnt do it again. Almost like it pushes an air pocket out then as soon as it cools down and you drive again it does the same thing.
Kinda at a lose. Possibly the waterpump not keeping up? It was used and looked mint and had "40k miles on it" Its cheap enough to swap but wanna bounce it off someone that maybe had the same issue.
Other thought is maybe gut the t stat and drive without it to see if maybe there is a pocket stuck right at the tstat. Maybe drill it?
Thanks for any input
Jay
Rundown on the car.
160* stat
4 port steam port routed to the top of the water pump (above the upper rad hose)
Fans kick on around 175.
Now I have bled the cooling system multiple times and ways. Pulled the steam tube off multiple times until all air is out, jacked the front up and used a funnel screwed into the rad filled with coolant etc.
The car still wants to overheat idle. It will get up to 220*, as soon as a blip the throttle it drops, if I continue to rev it say 1200+rpm it will drop down into the 160* range.
It seems to only happen once and then the car is fine.
I take it to work in the morning, as soon as I hit the drivethru (1min drive) the car gets up to around 210 degrees in literally 1 minute. As soon as I start driving it drops down to 160s in like 15 seconds. Then generally it is fine the rest of the time im driving, doesnt do it again. Almost like it pushes an air pocket out then as soon as it cools down and you drive again it does the same thing.
Kinda at a lose. Possibly the waterpump not keeping up? It was used and looked mint and had "40k miles on it" Its cheap enough to swap but wanna bounce it off someone that maybe had the same issue.
Other thought is maybe gut the t stat and drive without it to see if maybe there is a pocket stuck right at the tstat. Maybe drill it?
Thanks for any input
Jay
Thread Starter
11 Second Club
iTrader: (8)
Joined: Mar 2007
Posts: 569
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From: Windsor, Ontario Canada
Well after doing some reading I learned something i didn't know about pre 04 stuff at least Corvette pumps. Right now I have the heater outlet ports plugged on the water pump. Apparently this causes issues with water not flowing around the thermostat. Looks like I'll hook the heater core up tonight and see if that helps. Maybe the water pump is cavitating. Strange my last swap I had plugged. No issues. Maybe it's a stubborn air bubble trapped in that area.
Jay
Jay
Thread Starter
11 Second Club
iTrader: (8)
Joined: Mar 2007
Posts: 569
Likes: 3
From: Windsor, Ontario Canada
Hooked up the heater core and my spill free funnel. Couldn't get the car to heat up past 170s with the fans on. Disconnected the fans revved it a bit to get it to 190* hooked the fans up. Bam 170s in no time.
So note to those that block the heater ports, don't do it unless you drill a bypass inside the pump.
Jay
So note to those that block the heater ports, don't do it unless you drill a bypass inside the pump.
Jay
