lectroglide

Have a 95 with the typical cooling problem and seen/read couple things
that claimed you can stay kooler with a 180 degree tstat. does that really work or just fiction?

STL94LT1

Factory installed thermostat for your 1995 and all LT1's is 180°.

Whaleman

I just replaced my 96 base stock 180 deg thermostat with a new 180 deg thermostat from Ecklers and it made all the difference. Runs right at 194 deg driving at any speed over 20 MPH even with 90 deg outside air. Old one looked fine but seemed to be sticking. It runs 20 deg cooler than before. Dan

don hall

I'm not aware of the C4 having a "typical" cooling problem. Do C4s run hot? Yes, to provide for complete combustion, and reduce pollutants.

Owned a '93 for 12 years, and my '92 for 5, and never experienced overheating.

Cooling requires liquid flow, and air flow. Block one, or both, and you will experience overheating.

When was the t-stat replaced? When was the coolant flushed, including removal of the knock sensors? When was the radiator cap replaced, and the gasket inspected? When did you last check for debris blocking air flow in front of the radiator?

The vette requires a 'closed' cooling system, meaning, as the engine heats, coolant expands into the overflow bottle. At engine shut-down, the coolant cools, and returns to the reservoir via a siphon. Any entry of outside air will negate the siphon, and the reservoir will be low on coolant.

To answer your t-stat question, a lower rated t-stat will open earlier delaying the vette to reach proper operating temp. Once open, the
t-stat is out of the cooling equation, and has no influence on coolant temp.

anesthes

Lower the fan temps in the tune. When sitting in stopped traffic, once the temps creep up too high it's hard to get back down.

I never see more than 210 degrees on my LT1 car in traffic. A typical cruise is mid-high 180s.

Even my 600+hp supercharged Formula runs around 210 degrees at a dead stop.

The factory temps on all the emissions cars is way too high. The TPI cars are even worse, they run high coolant temps for complete combustion, then they run EGR valves to reduce combustion temperature.

Then they wonder why the oil control rings are cooked at 100k.


-- Joe

aklim

I doubt it does anything significant. The sticker is probably worth 10HP. OTOH, if your engine is set up with that in mid, maybe.

vader86

You already have a 180 degree thermostat in the LT1 engine. You do not need to go lower.

lectroglide

K thanx for the replys, had the car only 2 months and am still checking things out as I drive but from reviewing the replys here sounds like its time take care of a "to do list

I did notice when the cars cold the level on the lower recovery tank dipstick was at 1/3 as opposed where its spose to be on the lower mark, am not sure what that would indicate. at any rate the temp around here has been around 80-90 so the temp on the car slowly climbs up to 228 in city driving, so I turn on the AC and it drops, however if I get up to freeway speed it also drops with the AC off, anyway need to get some things checked out

JrRifleCoach

^^^^^ THIS! ^^^^^

don hall

The "lower recovery tank" can be called the over-flow bottle. When coolant heats, it expands, and pressure builds. The radiator cap is
designed to open at a certain pressure rate (about 16# - this pressure increases the boiling point about 50 deg.) allowing heated/expanded coolant to flow to the over-flow bottle. The over-flow bottle is not pressurized. The markings on the bottle - 'level when hot' - 'level when cold' are just suggestions. With a cold engine, it is important to fill the bottle to at least the cold level mark, or above. 'Level when hot' mark is not important, unless excess coolant is forced under extreme pressure out of the reservoir. This could mean a ruptured head gasket.

As a routine, you should monitor the flow of coolant. Check coolant level with a cold engine, then check coolant level after driving (at the bottle, not the reservoir, which is pressurized when hot). Then check coolant level after engine has cooled. The coolant level in the bottle should increase during driving, and reduce during cool-down as coolant is siphoned back to the reservoir.

lf there is no reduction of coolant in the bottle during the cooling process, your 'closed cooling system' has been breached, which means outside air is entering the cooling system through loose hose connections, frayed hose ends, deformed rad cap gasket, anything that will allow air to enter the system.

Outside air entering the cooling system will negate the return siphon, and the reservoir will remain low on coolant.

lectroglide

just went out and pulled the stick from the recovery tank the water line was above the 1st line that said Cold, in other words thiers the 1st line on the stick then above that COLD, the water line was above the cold
letters ,don't know if that means anything just thought Id mention it, also whoever did the last coolant the color is red prolly dextron


looking at the last owners receipts sez they used 15/50 mobile 1 at last oil change,
Never heard of that weight, can someone explain??

vader86

Its the orange dexcool.

15w50 is a heavier oil than is required but it is fine if you so choose, sometimes folks use heavier oils when they have worries about the engine getting older and bearing and ring wear, some forced induction engines require it, very hot climates/temps, racing, etc. A 5w30 or 10w30 would be more normal.

lectroglide

ok thanx, looking thru the past owners maint receipts all I can find is someone used 15/50 which I thought was odd, tried to contact them to no avail so guess will go back to 10/30

the cars only got 83 K

ctmccloskey

Here is my 2 cents worth,

Check your radiator cap, if it more than a few years old but a new one. They are cheap. Be sure that the cap is on and in "Position" so it can allow the overflow to work properly. Some caps have an arrow indicating where to position it to ensure that it is placed in the right position. I had somebody remove my cap and they did not put it on all the way and it stopped my overflow tank from helping. Instead it dumped antifreeze all over the ground because of no place else to go. Double check the hose that goes to the overflow bottle, any leaks will stop it from working properly. The fluid has to be able to travel both ways easily, one under pressure from the radiator and back to the radiator under vacuum.

Change the anti-freeze and flush the motor and radiator well in the process. Do not forget to remove the knock sensor to get all the coolant out of the block. Changing the coolant will help you start fresh with new coolant and be a good "starting point". Be sure to use distilled water and use only what antifreeze you need for your environment. I have seen several cars run hotter than normal because of too much antifreeze in the coolant. Antifreeze does not transfer heat the same as pure water does, too much may protect you if you live in Wisconsin but it hurts the cooling systems' ability to dump the heat out of your engine. There are a lot of people out there that will keep adding pure antifreeze until they upset the balance thinking that if "x" amount works than "x+" can not hurt. Also be sure to check your radiator for being plugged up in the front with leaves and other matter. This is very common with the radiator being all boxed up like it is in my '88.

Drive the car for a while with the new antifreeze and see what happens. If the car persists in running hot I would check the water pump and if needed replace it. I would also recommend using "Water Wetter" as that stuff really works, just do not use it with the red DexCool. I had a bad experience with the two mixed together.

If after all this your car is still a tad bit to hot for you then it might be time for a new aluminum radiator or a friendly mechanic or both!

I hope that you can resolve this problem easily and without spending a fortune. These cars are fun but they should not break your budget.
The best of luck!