joebeemish

I just had a rebuild, 383, heads, cam, electric water pump, etc done on my 95 Camaro. I have not tuned it yet, but I have driven it a little. It was over 100 here today and the temp gage went to almost 3/4 mark on freeway at 65 MPH in 5th gear. I turned off the A/C and it didn't help much. I know I need to tune it, but this shouldn't cause the temp to be this high (I think). The oil pressure is good, 1/2 to 3/4 on the gage.
Thanks.

Robs97Z28

did you replace or reuse the coolant senser? I would start by putting on a mech. gauge and varify what the temp is. That way you will know if you are truely running hot or not.

2ZPOINT

Make sure u have all the air out of the lines. Dam lt1s are hard to get all the air out. You think u have the thing full with water ,but u really don't. Not saying thats the case ,but make sure.

shoebox

Did you re-install the air dam? Gotta have it or it will run hot on the highway.

thrift23

When I got my car back from a rebuild it wsa running hot until I got the air out of the heater.

TobyZ28

Run the header on hot/high when bleeding the system, mechanic fergot to do that with mine. Once we did that the car didn't overheat any more.

joebeemish

Thank you all for the replies.
1) I reused the sensor. Where can I get a mechanical one for test purposes?
2) We tried to get all the air out. I thought the overflow cycle would take care of that after a few cycles.
3)The air dam is still there.
4) Why would turning the heater on high move water & air? My understanding is that the heater core is always cycling coolant, there is no in-line water regulator.

More data - it seems the car runs a little cooler when the A/C is on. Weird. Also, when I run the garden hose over the radiator when it is hot, the temp guage drops down to a little over the 1/4 mark after a minute or two - About where I think the car should run. I have a new electric water pump. The Mezier site claims they move more water than mechanical, but somebody else told me they didn't believe that. The fact that the water over the radiator cools the engine well says something, but I'm not sure what. Do the fans have any effect at 65 MPH? I would expect that at highway speed the fans don't contribute any cooling.
Thanks again.

TobyZ28

Honestly I'm not sure how the heater core thing works. What you said makes perfect sense... Perhaps he turned it on to aid in cooling while the engine was trying to bleed of air.

You didnt mention using the 2 air bleed screws at all. You MUST use those fellas while the car is idling to bleed the air out! Then the "hot cool" cycles will get the last bits of air out of the system. Also after you bleed the car properly, the next morning you can open the radiator cap (assuming the car is level or very slightly slanting down to the drivers side helps). If the coolant is right at the top everythings probably ok. IF its low, add more mixture then check it the next day again. If this continues the coolants gotta be leaking or the caps/overflow is letting air back in after it cools (air leak in the overflow tube... [unlikely though!]?)

The reason why the car cools a bit better with the A/C on is because it starts the fans sooner. err shoeboxes site has some details on the differences for different years. But basically the A/C on will engage your fans a good bit sooner than if you just had the heater or nothing on.

xxsaint69x

its the waterpump man....i had the same damn problem..car would run hotter with the CSI waterpump. Also probably more heat since the car is braking in.

I solved my problem by puttin in a 160 degree thermo. Now i have temps around 180 while cruzing on a highway and goes up to 195 siting (then both of my fans kick in and they bring it down to 190.

Marcin

442olds

What fuel injectors are you running. If you haven't upgraded the fuel injectors yet and are running stock programming for the 350, there is a good chance your running lean enough to overheat. I had this problem while I was waiting for my 30 lb injectors to arrive.

Robs97Z28

finding mech gauge is fairly easy, places like Summit, Napa, Autozone and Pepboys, just to name a few. Will have what you are looking for. If you have a scanner you can also plug it in and find out what temp the comp is seeing. Then you can compair the two, they would read the same , but should be fairly close.

joebeemish

Thanks again for the replies.
The Collant system was bled, but I will bleed it again. Should I do it when the engine is hot?
I will try a cooler thermostat when I do my programming and turn the fans on earlier.
I am using the stock 24 lb injectors. I have 42.5 lb injectors ready to go after I can program the computer.
Where does the mech gage plug into?
Thanks again.

2ZPOINT

YEA...bleed it with the engine warm....get all that air out. It will steam out the bleeders when the motors hot. Like I said lt1 coolant systems are a pain to bleed all the way. This sounds like the obvious,but you thermostat could be stuck. Good Luck

pu12en12g

Whoa... this is good info !