bad water pump?

[RAF7789]

alright, ive checked every cause i could think of, for why its overheating. at high way speeds in 6th going.....65-85mph, its steady at around 235*. I made sure that my fans were plugged in and functional and they were. i also made sure nothing was stuck on the radiator. i've bled the system 5x and no air comes out. the conclusion i am coming to is that the water pump has either lost its prim or is in progress of losing it. i will check it tonight when it cools down.

[RangerBob]

Is your air dam intact?

[RAF7789]

there is no air dam on mine. what is stumping me is that it was running cool (185-200*....it never even got up 220*) before i replaced the opti, although the w/p was out of the car for like 3 weeks. and i didn't drop it or anything. could some residual coolant dried up on the inside of the water pump and clogged it?

[TraceZ]

there is no air dam on mine. what is stumping me is that it was running cool (185-200*....it never even got up 220*) before i replaced the opti, although the w/p was out of the car for like 3 weeks. and i didn't drop it or anything. could some residual coolant dried up on the inside of the water pump and clogged it?

Water pumps don't really clog up.

Try installing the air dam. These cars are bottom breathers, without the air dam they do overheat.

[TraceZ]

It's also possible you put the wrong thermostat in it, or installed it upside down. A regular SBC thermostat will not work in a LT1.

I really recommend installing the air dam, though. My money is on that.

[Christopherrr]

+1 on the air dam.

[Joe 1320]

Without the air dam in place, the cool air goes under the car instead of being deflected up though the radiator.

[RAF7789]

when i bought it, the dam air dam waswas already taken off. I am sure the t-stat is correct. and agian, the car was running cool for the 3 months after i bought it (w/o air dam).

[TraceZ]

when i bought it, the dam air dam waswas already taken off. I am sure the t-stat is correct. and agian, the car was running cool for the 3 months after i bought it (w/o air dam).

I'm shocked it was running cool thus far.

Seriously, get an air dam. These cars will overheat without one.

[RAF7789]

an interesting discovery was made. My radiator hoses feel like they are empty...regardless of if the car is running or not. i unscrewed both bleed valves and nothing came out. when i squeeze the hose, very little, if any, coolant arrives at the valve. yet the radiator was full with dex/water blend. im starting to think this is the winchester mystery car.

[axgrndr]

im gonna take a stab in the dark here. as stated a few times before i'm no expert. but.. engine hot and hoses dry but radiator wet.. my guess for what its worth.. is one or more of the following.. one bad pump. two bad radiator cap. three a leak via a hose, heater core, internal in the block, or even radiator drain petcock. do a pressure check. look and smell for glycol(coolant). should help isolate it. oh yeah.. get an air dam after you figure it out. will help regardless. and not raggin on ya but ..seriously its kinda a required equipment thing unless youre an 80yr old grandma that goes 2 blocks to the grocery doing idle the whole way.- ron

[axgrndr]

also to add. the thermostat could have gone bad as well or be in backward as mentioned earlier. if the pressure check turns up ok id look at that or the pump. on a different note im stealin copy of your chruch sign pic.. grand pop was a minister. lol. later- ron

[RAF7789]

ok well today, after driving about 15 miles at 65mph, the temperature was right at 220*F. then when i got home and popped the hood, the hoses were running coolant and to just to make sure, i opened the bleed valves and coolant sprayed out. So that confirmed it.

also i'm not (noticably) loosing any coolant.

[Joshu]

Any chance that your thermostat isn't opening up all the way?
Take it out and throw it in a pan of water. Put the water on the stove. Once the water gets hot the thermostat should begin to open up. Also, is it possible your radiator cap (where you add the coolant, not the reseviour) is dirty and clogged?

[97LT1Z28]

I also agree on the airdam. Make sure you get the LT1 Thermostat - most auto parts places I go to ask me the engine size and I say LT1 and their response is always "oh, 350?" and I say no......LT1 - if you give me the thermostat for the Chevy 350, it's the wrong one.

Also, I recently had a coolant bleeding problem where I couldn't get the system to bleed - I couldn't get all the air out. What I had to do is warm the engine up, hold the throttle to rev the motor to 3K RPMs (doesn't have to be exact...) - while holding the engine at the 3K RPMs, then open the bleeder screws. Air would come out but only when reved up. Then I would re-tighten the bleeder screws when coolant came out and then let the RPMs down. It worked like a champ. Those air bubbles can get that temp up quick!