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Old Apr 16, 2013 | 06:23 PM
  #1  
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Default Cooling Issues

I've had cooling issues with my car for a while now. Runs about 210-215 degrees in 70-80 degree weather. After running through the gears, this will rise to 215-220 degrees temporarily, then return to 210-215 degrees. FYI - 347ci heads and cam car, see signature for setup.

What has been already replaced/addressed:
- Swapped in a new LT1 radiator in place of the stock LS1 radiator.
- New LS1 water pump.
- Recently tuned with the new motor so excessive timing is not an issue, as well as fan "on" temperatures.
- Existing stock LS1 thermostat. (Roughly 6k miles on this thermostat FYI)
- No air in the system, bled the extra air out and use a 50/50 mix of Dexcool coolant.
- Not low on coolant in the radiator or overflow reservoir.

What I think could be the culprit:
- SSRA blocking radiator for proper cooling. Temperatures are high whether idling at a stoplight or cruising at highway speeds.
- Thermostat spring is shot from running hot previously (highest was 230 degrees).
- Dashboard temperature gauge is simply not accurate and it's really not running hot.

I know LS1's typically run a little hotter than a traditional SBC, but 210 degrees seems too high. Also, in warmer weather with hotter coolant temperatures, the car definitely feels down on power. I really want to fix this cooling problem.

Thoughts? Thanks.
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Old Apr 16, 2013 | 08:52 PM
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Is that annoying lip air dam that drags when you turn into driveways still in place?

Removing makes the temps go up & up & up on the highway.
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Old Apr 16, 2013 | 09:57 PM
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You need a scanner of some kind to read from the computer, the dashboard gauge isn't accurate, you could be running hotter, or colder than you think. Although if it moves past 210 it's likely getting a little hotter than 210, you're just in the dark if you rely on the needle in my opinion.
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Old Apr 16, 2013 | 10:56 PM
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you could always try a 160 stat........
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Old Apr 16, 2013 | 11:14 PM
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Listen here dirtbag.....lol.....had to say it.......

Anyway.....yes, 215 is too hot in my opinion. it would drive me insane if my temps were like that. my 427ci always ran around 195*F in hot Florida weather. There's something wrong. A very common thing for people to do when swapping a radiator is they do not get the fan housing back on perfectly snug up against the new radiator. Make sure the fan shroud is tight up against the radiator, and that the shroud is hanging on all 4 hooks. If the shroud is bent up or damaged or there's a gap in the shroud between the radiator and shroud......you're doomed, you will run hot. That causes the air from the fans to be wasted.

Lower front air dam needs to be perfect, no damage. This is mainly for cooling while cruising on the highway.
Fans do all the cooling, or almost all of it while at low speeds and stop and go driving.

And personally, I'd run a half jug of anti-freeze, just a HALF jug....the rest water.

Maybe change the t-stat again....lots of times new t-stats are just duds.....

The fans......make sure they are BOTH coming on at the same time and that BOTH are running in both LOW and HIGH settings. Next time your temps read 215, pull over and with your hand make sure BOTH fans are on. Fans on our cars always run together and go off together.
.....I would buy a laser temp gauge to check the temps with.....don't rely on the gauge in the cluster.......Use the laser and aim it right at the drivers side head right next to the temp sensor to get the best reading.


.
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Old Apr 16, 2013 | 11:21 PM
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Originally Posted by sjsingle1
you could always try a 160 stat........
Would not make a difference.
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Old Apr 17, 2013 | 12:16 PM
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What temp are the fans set to come on at?
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Old Apr 17, 2013 | 12:30 PM
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Thermostat makes zero difference here.

Fan settings must be fixed, they simply suck from
factory.

Then, go blow out the condenser and the new radiator,
reverse flow, and see how much debris you get.

Ducted cold air systems do shroud the condenser and
could be adding to the situation. That should be easy
enough to test.
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Old Apr 17, 2013 | 01:37 PM
  #9  
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Originally Posted by LS6427
Listen here dirtbag.....lol.....had to say it.......

Anyway.....yes, 215 is too hot in my opinion. it would drive me insane if my temps were like that. my 427ci always ran around 195*F in hot Florida weather. There's something wrong. A very common thing for people to do when swapping a radiator is they do not get the fan housing back on perfectly snug up against the new radiator. Make sure the fan shroud is tight up against the radiator, and that the shroud is hanging on all 4 hooks. If the shroud is bent up or damaged or there's a gap in the shroud between the radiator and shroud......you're doomed, you will run hot. That causes the air from the fans to be wasted.

Fans are snugged up to radiator. No shroud damage. No problem here.

Lower front air dam needs to be perfect, no damage. This is mainly for cooling while cruising on the highway.
Fans do all the cooling, or almost all of it while at low speeds and stop and go driving.

Lower front air dam is in good condition. No problem here.

And personally, I'd run a half jug of anti-freeze, just a HALF jug....the rest water.

Will try this.

Maybe change the t-stat again....lots of times new t-stats are just duds.....

I'm putting a 160 degree thermostat in for the heck if it. My tuner has set the fans for a 160 stat so it should no issue to make the switch over.

The fans......make sure they are BOTH coming on at the same time and that BOTH are running in both LOW and HIGH settings. Next time your temps read 215, pull over and with your hand make sure BOTH fans are on. Fans on our cars always run together and go off together.
.....I would buy a laser temp gauge to check the temps with.....don't rely on the gauge in the cluster.......Use the laser and aim it right at the drivers side head right next to the temp sensor to get the best reading.

Definitely gonna try the laser temp gauge. Both fans do come on correctly.

.
Answers are in the quote. Thanks for the responses guys. I'll respond with the results as soon as I can.
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