180 or 160 Thermostat for 04 LS
- Thread starter 04SCTLS
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97stscaddy
Dedicated LVC Member
You need to hook up with whoever you got the tune from and get them to correct it. Or run better gas. Engine coolant temp would have nothing to do with pre-detonation unless the engine was overheating.
Might also try using some strong fuel injector cleaner, and replacing the fuel filter first.
I got the tune direct from SCT. I was running 91 but now use 93 only. This "pinging" only showed up briefly under WOT when the outside temp was over 90.
It didn't sound like the usual baby rattle pinging noise but was more subtle and subdued.
I run 87 in my chev pickup through the colder months here in buffalo
but get some pinging in 4th OD gear in the summer which goes away if I run 89.
I want to run a cooler thermostat anyways and see that Advance Auto Parts sells one.
I can cut back the timing by 1 degree using the SCT flasher but want to try this approach before retuning.
It didn't sound like the usual baby rattle pinging noise but was more subtle and subdued.
I run 87 in my chev pickup through the colder months here in buffalo
but get some pinging in 4th OD gear in the summer which goes away if I run 89.
I want to run a cooler thermostat anyways and see that Advance Auto Parts sells one.
I can cut back the timing by 1 degree using the SCT flasher but want to try this approach before retuning.
nearlyhalfamile
Active LVC Member
You could try using water wetter in the coolant system as well. It won't lower the overall temp of the engine, but it will help reduce hot spots in the cylinder heads under WOT.
Thanks for water wetter tip.
I've been running a 160 thermostat in my supercharged LT-1 5.7 liter Camaro convertable for years with no problems.
The temp guage never goes over 195.
I have various scanning software that works with an elmscan interface and they show the LS running much hotter at about 220+.
I have the Livewire tuner and will have to check if I can reprogram the cooling fan to turn on sooner.
I believe so but if not I'll get SCT to do that for me.
Unlike the much more complex LT-1 Edit software I have for the Camaro,which has a changeable advance vs load table with 14 kpa lines from 25 to 100 in 5 kpa increments and 24 rpm columns from 600 to 7000, the Livewire will cut the advance across the board and I don't want to do that as I'm very happy with the part throttle response right now.
I think cutting 30+ degrees off the coolant temperature will add a few more HP as the car seems a little more perky before it warms up.
I don't WOT the car if it's cold as I don't want to harm the engine and it heats up to operating temp very quickly but lower coolant temperatures will translate into lower air intake temperatures due to heat soak.
I've been running a 160 thermostat in my supercharged LT-1 5.7 liter Camaro convertable for years with no problems.
The temp guage never goes over 195.
I have various scanning software that works with an elmscan interface and they show the LS running much hotter at about 220+.
I have the Livewire tuner and will have to check if I can reprogram the cooling fan to turn on sooner.
I believe so but if not I'll get SCT to do that for me.
Unlike the much more complex LT-1 Edit software I have for the Camaro,which has a changeable advance vs load table with 14 kpa lines from 25 to 100 in 5 kpa increments and 24 rpm columns from 600 to 7000, the Livewire will cut the advance across the board and I don't want to do that as I'm very happy with the part throttle response right now.
I think cutting 30+ degrees off the coolant temperature will add a few more HP as the car seems a little more perky before it warms up.
I don't WOT the car if it's cold as I don't want to harm the engine and it heats up to operating temp very quickly but lower coolant temperatures will translate into lower air intake temperatures due to heat soak.
97stscaddy
Dedicated LVC Member
Your coolant should be boiling at 220°, or very close to it. That would put the needle in the red zone at the top of the gauge. I kinda doubt its running THAT hot.
You could probably use a 180° stat and be OK, but any lower and the ECM might not ever come out of closed loop operation, thinking that the engine is too cold all the time. Closed loop advances the ignition timing (which is why it feels "peppier" below normal operating temp) and makes it run rich to warm up the engine, catalytic converters, and O2 sensors.
nearlyhalfamile
Active LVC Member
Coolant will start to boil around 275+, not 220... Most cars have an average coolant temp of 220 or so and it would be about midway on the gauge.
Closed loop issues usually only come about from running no thermostat.
Jim Henderson
Dedicated LVC Member
A colder thermostat only controls how soon the Tstat opens. Once the engine is warmed up to normal operating temperatures, the coolant will usually be above the the Tstat rating all the time. Only when the temperature is cold will the Tstat do much once the engine is warmed up.
A negative of a cold Tstat is that you may not burn off contaminants in the oil during cold weather and your may be "washing" the cylinder walls with gas(running rich) when cold which increases wear on pistons.
A cold thermostat can help performance only if the engine stays cool. It won't stay cool on a hot summer day or sitting in the line at the drags. Once it gets to normal temp, there is no more benefit. Only way to keep it cool all the time is a bigger radiator.
The automakers choose their Tstats carefully for an "optimum" reliability, drivability, smog, longevity and performance. Changing the rating without considering what you want and what else is involved can have effects you don't want or expect.
You probably need better gas or need to clean out deposits in the engine.
Good Luck,
Jim Henderson
A negative of a cold Tstat is that you may not burn off contaminants in the oil during cold weather and your may be "washing" the cylinder walls with gas(running rich) when cold which increases wear on pistons.
A cold thermostat can help performance only if the engine stays cool. It won't stay cool on a hot summer day or sitting in the line at the drags. Once it gets to normal temp, there is no more benefit. Only way to keep it cool all the time is a bigger radiator.
The automakers choose their Tstats carefully for an "optimum" reliability, drivability, smog, longevity and performance. Changing the rating without considering what you want and what else is involved can have effects you don't want or expect.
You probably need better gas or need to clean out deposits in the engine.
Good Luck,
Jim Henderson
I usually run 91..and sometimes 93..in my '02 V8. I have very slight pinging at WOT at high temps as well. Very slight.
In my experiences, this is within the "normal" range. Slight pinging isnt a problem. When I had my plugs replaced around 65k or so, they looked fine. Very fine actually. Not overly rich, not overly lean. Nice tan/beigish electrodes with no chipping, etc.
In my experiences, this is within the "normal" range. Slight pinging isnt a problem. When I had my plugs replaced around 65k or so, they looked fine. Very fine actually. Not overly rich, not overly lean. Nice tan/beigish electrodes with no chipping, etc.