Anybody out there have experience in attempting to reduce 95 base model overheating? Since I'm having leakage (expecting plastic leak) am wondering if going to a full aluminum 3 row radiator might help and if significant mods are required to install using existing stock fans and mounts. Signed Hot and Bothered

 

I would start by diagnosing why the coolant is getting hot, but what temps do you see that you feel are "hot"??

C4 coolant temps are "hot" by design in order to help reducing emissions. There is nothing wrong with coolant temps anywhere from 180 to as high as 220.

 

Knowing you did not ask.. I have replaced radiators many times for an LT1 engine. The upper radiator housing is a bit of a PAIN to get removed to service the radiator (without cutting it)....the 7mm screws on the side is where the problem is. This is due to this assembly is installed as a unit...and if you take it out as a unit...the A/C will need to be evacuated/recharged.

AS written by 'c4cruiser'..it is not uncommon for you to feel that the temp is HIGH...IF you are looking at the temp gauge. The GAUGE is NOT linear. So using your 'GAUGES' button on the dash will show the actual temp in numerical value near your speedometer.

Cooling fans come on at or around 226-228 degrees Fahrenheit.

The main problem that I come across is the amount of debris ( pine needles, cracker wrappers, bird feathers, etc) that block the primary fan on the left side.....thus impeding the effectiveness of it when it comes on. I have been doing this so long now...it is one of the first things I look at when a Corvette with a LT1 comes in my shop. I have made a special blower that can reach down in front of the fan from the right side and blow out all the crap. Then I test it to see how well the fan performs when I warm up the engine and get the fans to come on.

Using an aluminum radiator is not going to change the way the fans come on...and it may help...but that all depends if you are looking at the gauge...or using the GAUGES button...but I would be MORE CONCERNED that the coolant is good...the knock sensors have been removed and the block drained....and FRESH COOLANT MIX is added...MAKING SURE that if you mix your own coolant...USE DISTILLED WATER!!!!!!

Verifying that the radiator cap is GOOD...and also...when you do this...I remove the small hose that attaches to the top of the radiator on the right side....then follow it over to your expansion tank and remove it....then follow this same hose over to the back of the right head and remove it off the tube. I want to blow out and flush this line out. WHY???? Because they can get blocked up with crap if the coolant system has been neglected.

Also...you are aware that filling the engine/radiator with coolant requires a SPECIFIC procedure. It is not just putting coolant in the expansion tank. If you do it that way ONLY...you will trap air and have a PROBLEM.

DUB

 

I purchased a champion 3 core alum. radiator about a year ago. I think it was $175.00 or so. So far, it was worked well. If yours is leaking, then you are going to need to replace it, even if you are not overheating.
Lots of good info already posted above. But I would like to add, in order to get it to run cooler then the 210-230 factory range, you will need to change the T-stat from the factory 180 to a 160. This will help when going down the road, but when you are in stop and go traffic it will heat back up to the factory settings. In order to keep it cool at idle, and stop and go, you will need to have the computer reprogrammed along with the 160 t-stat.
I would look to pcm4less in NC for that service. He can make some other small gains in the tuning of a stock motor.

 

This is very vague..

What are your temps?

Now keep in mind, water boils at 255°f @ 15psi. If you have a leaky system it will boil much sooner, such as leaky end caps.

 

Three row radiator may not see the temps you think. Make sure when installing new radiator that the condensor is clean. You have a 180 thermostat. The cooling off period is faster with a larger radiator.As this was stated above some people reprogram the fans and put a 160 stat to make it run cooler in traffic. I have a Dewitt's rad and it is made really well. My system fans and stat are stock. The temps vary a few degrees cooler but cool off faster. I also have a 95.

 

On my own radiator it was a day's project with a small dental pick just removing hundreds of little things, seed, insects, grains of sand, who knows what that had lodged in the cooling fins themselves, and I'm sure the cumulative effect was a substantial reduction of flow through the radiator core...

As far as filling the radiator, even using the bleed screw, it took four or five separate attempts, (start up, come to operating temp, shut down, allow to cool off, bleed more air, add more coolant, repeat) before all air was purged from the system.

 

I may run into a scenario when I open up the bleed fitting and add coolant in the expansion tank....and no coolant comes out of the bleed fitting....but the expansion tank fills up.

I close off the bleed fitting...and then crank the engine for a few seconds...shut down the engine....and then open up the bleed fitting again and completed my fill. And I also open up the bleed fitting under the throttle body on some years that have it.

I have not had to do what you did to get it full. I would be way to concerned about the air pocket at the thermostat by running it to operating temp.

DUB

 

Thanks for your response. Temps (digital) reach 250-260 sometimes in traffic, actually blowing heater hose on one occasion. Recently found evidence of spray all around lower rad hose area though never saw a leak point, but, water on floor overnight after cooling. Others have suggested removing knock sensors and draining block or removing expansion tank/overflow lines to ensure clear. Have noticed no overflow tank level above cool mark, ever. Am using Water Wetter which seemed to lower op temp ~ 10 degrees, but, once at stoplight tempcreep. Fans working properly. Suspect problem may be related to improper filling/bleeding. Will regroup after various attempts to rectify. Old man, squatting hurts. Can't wait to respond with WooHoo smily.

 

You've given me some things to digest and redirect. Thank you.

 

You do have the front air dam connected on your car???

What type of coolant are you using???? Old style green or the newer orange Dex-Cool???

I can agree with pulling out the knock sensors....you might be amazed with the amount of red clay looking crap that comes out of the block when it is also done draining.

DUB

 

When you hit 250-260 in traffic, does it cool down once you get the car up to speed, say above 35mph? If so, have you checked to see if the fans are coming on?

 

If you put the a/c on both fans should be operating. As mentioned previously do you have the front spoiler on. Your temps are too high. On the hwy it should cool down.

 

Yes, the original dam is still in place and I am using the orange Dex-Cool. The knock sensors look a bear to remove, I'll have to wait till my Doc says I can perform strenuous bending/grunting/cussing/knuckle-busting and more cussing. The big H surgery.

 

Yes fans working as prescribed in shop manual and temps lower to normal when moving > 25.

 

Be AWARE that there is a 50/50 chance that the knock sensors will spin when you attempt to remove them. IT IS WHAT IT IS. when this occurs...I have to tack weld the spinning portion where you put your socket to the housing and then remove them. TRUST ME...it is the fastest way...and is still a ROYAL PAIN. I have tried numerous other ways and they just do not work due to clearance issues. So...when ti occurs...I have my welder on stand by and I tack weld them...then I replace them with new ones.

Have you looked to see if the radiator is blocked in front of the left cooling fan???

Do you have a cooling system pressure tester and one that can check the radiator cap???

All that I wrote in POST #10 is important and are things that I do and check....and should not be overlooked.

IS everything OK now...In POST#15...you wrote that it is doing fine when driving???

DUB