LT1 Still Running Hot
Burning Brakes
Joined: Oct 2004
Posts: 1,210
Likes: 1
From: fighter pilots make movies, bomber pilots make history
You can program the low speed of fans to on/off @192/186F
The factory setting low speed is on/off @ 226/221F
The thermostat (190, 180, 170, 160) sets a floor on the cooling system temp, but the low speed fan setting controls the temperature range at slower city driving.
I have a 160 thermostat and fans set @ 192/186. I run minimum of 185 digital and about a 100F differential to ambient (if 95F ambient, 195F digital reading). Stock radiator.
Tranny temps about the same as coolant temps +10F.
Leave your thermostat as is and lower the fan on/off temp, cheaper and easier than tranny cooler. Although tranny cooling is good on any machine.
I used a HyTech programmer on my 95 that a friend gave me. You can set a few other parameters... fun to play with. Easily changed back to factory settings.
Joe
The factory setting low speed is on/off @ 226/221F
The thermostat (190, 180, 170, 160) sets a floor on the cooling system temp, but the low speed fan setting controls the temperature range at slower city driving.
I have a 160 thermostat and fans set @ 192/186. I run minimum of 185 digital and about a 100F differential to ambient (if 95F ambient, 195F digital reading). Stock radiator.
Tranny temps about the same as coolant temps +10F.
Leave your thermostat as is and lower the fan on/off temp, cheaper and easier than tranny cooler. Although tranny cooling is good on any machine.
I used a HyTech programmer on my 95 that a friend gave me. You can set a few other parameters... fun to play with. Easily changed back to factory settings.
Joe
I put a dewitts radiator in my 95 LT1-It still runs around 200 hwy driving and it will rise up to 228 in traffic if the a/c is not on.I thought by using this rad the temps for cruising would be about 190 with a stock stat but I was wrong-It will take a little longer for the temps to rise compared to the stock radiator. I kept everything stock except for the rad. Running that hot will make the trans temp run hot that is why Im putting in a trans cooler
I would go back to the stock thermostat and start from there.
I would go back to the stock thermostat and start from there.
Last edited by devildog; Oct 24, 2009 at 04:49 PM.
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
Burning Brakes
Joined: Oct 2004
Posts: 1,210
Likes: 1
From: fighter pilots make movies, bomber pilots make history
A little high jacking, but a good conversation about C-4 cooling system.
Last edited by devildog; Sep 6, 2009 at 03:23 PM.
2nd Gear
Joined: Sep 2009
Posts: 2
Likes: 0
From: Sandy Utah
made to run hot
The system was designed to run hot. I know it can freak you out after being used to 180 Deg. engine Temps. I can see that the LT1 can run at 210 Deg. and accelerate on a 7% grade with no preignition. If it pings you have a problem! don't freak, thats the reason for running synthatic oil, it can take the higher operating temps.
Thread Starter
Burning Brakes
Joined: Feb 2002
Posts: 804
Likes: 5
From: Fresno CA
I did thanks. I picked up a 180 stat from Napa on Saturday and drained the cooling system and removed the other stat and just as suspected it was not the correct one. Evidently the last guy who worked on it put the wrong one in and then so did I...I can't believe I let that get by me
Anyway, no harm fortunately, then I removed the upper radiator enclosure, which was missing a couple of the small screws on each side indicating someone had been in there before and gotten lazy when reinstalling everything. When I removed the shroud I found very little debris between the condenser and the radiator although I shop vac'd and blew everything out and interestingly enough I discovered the radiator was a replacement unit (it has a tag on it says something like OEM quality or something, imported replacement no doubt, but it looks very new). I then put everything back together and replaced the o-ring on the CPS sensor which looks like it had a slight leak. I still have to replace the front air dam and refill the cooling system tonight and then we will see how it goes. Now I'm wondering where I should have the fans come on now that I've gone to a 180 stat. Low speed on at 205 off at 190 or somewhere in there perhaps?
Anyway, no harm fortunately, then I removed the upper radiator enclosure, which was missing a couple of the small screws on each side indicating someone had been in there before and gotten lazy when reinstalling everything. When I removed the shroud I found very little debris between the condenser and the radiator although I shop vac'd and blew everything out and interestingly enough I discovered the radiator was a replacement unit (it has a tag on it says something like OEM quality or something, imported replacement no doubt, but it looks very new). I then put everything back together and replaced the o-ring on the CPS sensor which looks like it had a slight leak. I still have to replace the front air dam and refill the cooling system tonight and then we will see how it goes. Now I'm wondering where I should have the fans come on now that I've gone to a 180 stat. Low speed on at 205 off at 190 or somewhere in there perhaps?
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
Well if you are going to keep the 180 in there I would set fans to factory since the 180 is the factory t-stat. I dont believe you will find any other LT1 style t-stat other then a 160. To each his own, but if it is mine I would go with a 160 and lower fans about 20 degrees each.
Tempature wise, the 160, in a LT1 will run about like a 180 in a sbc1 due to the reverse flow.
Tempature wise, the 160, in a LT1 will run about like a 180 in a sbc1 due to the reverse flow.
Thread Starter
Burning Brakes
Joined: Feb 2002
Posts: 804
Likes: 5
From: Fresno CA
Well if you are going to keep the 180 in there I would set fans to factory since the 180 is the factory t-stat. I dont believe you will find any other LT1 style t-stat other then a 160. To each his own, but if it is mine I would go with a 160 and lower fans about 20 degrees each.
Tempature wise, the 160, in a LT1 will run about like a 180 in a sbc1 due to the reverse flow.
Tempature wise, the 160, in a LT1 will run about like a 180 in a sbc1 due to the reverse flow.
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Burning Brakes
Joined: Dec 2007
Posts: 805
Likes: 3
From: Waco TX
I hear DeWitts are great, but not worth the ~$500 it costs. I would go with one if I had a heavily modded engine or something.
I found the stock radiator to be adequte as long as it is clean INSIDE AND OUT.
The only way to clean it is to remove the radiator, spray a power washer through the fins to get rid of all the grass that has bound to accumulated there over the years. Take it to a radiator shop and have them pop one of the side tanks off and run a bar through each of the tubes. Most radiator shops will do this for $75 bucks or less and that includes replacing and resealing the side tank they remove with a new one. The literally run a dipstick like bar through each of the tubes as if it were the barrel of a gun. Thats less than paying for a new stock radiator and a HELL of a lot less than a DeWitts. What is crazy is that a lot of people don't know this can be done. Rarely do I ever see it as a reply on the "overheating" posts.
About half my 94's tubes were clogged. I would reach 230+ degrees in traffic. And stay hot even cruising and highway speeds. After the cleaning, it is night and day better. Runs 175-185 on the highway. And 185 to 210 in town. And 210 is only if its 100+ degrees outside and I am stuck in traffic for a long time.
I have taken it autoXing only once since doing this and it only got up to about 220-225 and only after 2-3 runs. And this was in 100+ degree August heat in Texas.
I found the stock radiator to be adequte as long as it is clean INSIDE AND OUT.
The only way to clean it is to remove the radiator, spray a power washer through the fins to get rid of all the grass that has bound to accumulated there over the years. Take it to a radiator shop and have them pop one of the side tanks off and run a bar through each of the tubes. Most radiator shops will do this for $75 bucks or less and that includes replacing and resealing the side tank they remove with a new one. The literally run a dipstick like bar through each of the tubes as if it were the barrel of a gun. Thats less than paying for a new stock radiator and a HELL of a lot less than a DeWitts. What is crazy is that a lot of people don't know this can be done. Rarely do I ever see it as a reply on the "overheating" posts.
About half my 94's tubes were clogged. I would reach 230+ degrees in traffic. And stay hot even cruising and highway speeds. After the cleaning, it is night and day better. Runs 175-185 on the highway. And 185 to 210 in town. And 210 is only if its 100+ degrees outside and I am stuck in traffic for a long time.
I have taken it autoXing only once since doing this and it only got up to about 220-225 and only after 2-3 runs. And this was in 100+ degree August heat in Texas.
Thread Starter
Burning Brakes
Joined: Feb 2002
Posts: 804
Likes: 5
From: Fresno CA
Yeah this car is all stock so the fact that it has a nearly new radiator should be sufficient I would think. I just took a radiator from a Grand Am I have to the radiator shop and for 55.00 I got it back all rodded out, with a new end tank with the A/T cooler & gasket, all painted just like new! That can be the way to go for sure. Now on my 85 with the 408, that's a different story....I see a Dewitt's in my very near future
Instructor
Joined: Apr 2007
Posts: 228
Likes: 0
From: Pittsburgh (wexford) PA
I put a Dewitts in my 93 and did my first track day tonight since the install. Unbelievable difference. I went from 226 degrees after 6-7 laps to 190 degrees. I'm a Dewitts convert
Mike
Mike
Le Mans Master
Joined: Apr 2000
Posts: 5,713
Likes: 105
From: Manassas VA
Burning Brakes
Joined: Oct 2009
Posts: 773
Likes: 2
From: Minneapolis MN
Flush cooling system & engine throughy.Replace radiator with aftermarket/performance radiator.Replace coolant with GREEN.If stills runs hot,you either have air in system or head gasket problem.
