I recently traded a 95 Z28 and $1000 for my 1979 monte carlo, the car ran god for the 1st day or so, even went on a 3 hour freeway drive... but when i got back into town, i had a MAJOR overheating problem, nothing would stop it, i was topping out. So i went home, replaced the thermostat, and wired the coolant fans to an switch under my dash, because i had originally noticed that the fans werent cutting on, even with the A/C on.... turning the heater on did nothing, so i wired the fans on. Anyways, the problem was cured for another few hours, so i went on a drive around town, and it came back..... car is bustin 260 degrees! with both fans running! someone tell me what i am missing... cracked head? already? or maybe the water pump? and is the water pump manual or electric... because i swear on everything either i wasnt looking at the water pump, or the pump i saw had no pulley on it.... like... it looked as if it was electric... someone help me! oh... and my "Service engine soon" light came on recently.... and like... every once in a while, the car jerks when i hit the gas... almost like an oldschool v8 with a serious timing problem... but it only happens occasionally, although, i havent been able to ride it much, considering the overheating problem... HELP!!!!!!

 

Lt1 water pump is driven off of the cam VIA a driveshaft in the backside (between it and the block). Looks like its time for a new thermostat/water pump

 

well like i said, i replaced the thermostat, do u think that the water pump would trip a check engine light? and make it run erratic? or maybe the underhood heat just screwed a few sensors lol thanks alot man, hope to hear more from u soon

 

The M/C has an LT1? You don't want to overheat an LT1. You will be looking at blown head gaskets and lots of problems.

 

lol no no no no.... i had a 1979 monte carlo.... i traded this guy my monte... for his 95 Z28, and he still has to give me $1000..... as for overheating.... you think having to drive it back home, then to the shop is gonna run me a new head gasket? i had to do what i had to do..... i mean i cant leave the car there..... i didnt drive too long. and honestly? when i popped the hood, the heat was NOWHERE as hot as i thought it would be, readin 260 degrees.... you would think there would be some serious heat coming from the motor... it was hot... but not THAT hot...

 

i would hope that the problem wasnt THAT serious... a friend said maybe a cracked head, but im hoping for something much less than that...

 

Drive it there, and fix it. As long as you get there before it gets hot you'll be fine. I hope you bought the $18 thermostat and not the $4 SBC thermostat, because the $4 one isnt the right one, see THIS http://shbox.com/1/tstat.jpg (courtesy shoebox) I wouldn't worry about the head(s). Get it fixed, then deal with them.

 

i think i did get the cheapie one.... i noticed the valve on the new one was quite a bit smaller than the one in there..... could that be a problem?

 

That could be the problem. You may want to have the radiator checked and cleaned, it may be clogged up after nearly 10 years on the road.

 

I would get some of that radiator flush that prestone makes and drain it out and put that stuff in with water after you get the right thermostat. I paid $10 for one at advance auto.

 

You do need a specific thermostat for the LT1. If you can't get one at a parts store go to the dealership. I use the Hypertech 160 degree thermostat in all my LT1 cars. Remember the LT1 is a reverse flow cooling system not like a traditional small block. After you drain your radiator, you can drain your block by removing the knock sensors which are located at the bottom of your engine.
Once you flush your engine be sure to bleed off all the air in the system by using the bleeder screw on the thermostat housing. If your new to LT1's a Haynes manual is a good investment. You can get one for around $14 dollars at most parts stores.
Are both your radiator hoses warm/hot??

 

There's only one knock sensor on a Z28 and it's in the passenger side block drain.Other side is a reg pipe plug..
Did you bleed the system properly after the thermostat install?
It matters....

 

no i didnt bleed it like i should have... didnt know i was supposed to lol but i took the thermostat out... and have the fans runnin 24/7 so, i think im all good. reverse flow cooling? does that mean the thermostat should be sitting "upside down" as opposed to traditional small block thermostats, where the direction of flow is down into the block, and the pointy end is up, should i face it down? im not quite getting that. as for the bleeder screw? what bleeder screw? i have a standard thermostat housing with 2 bolts on either side.... no bleeder screw.... help?!? lol

 

You have two bleeder screws.

http://shbox.com/1/bleeders.jpg

Your thermostat will install just like a normal SBC. Please don't try to flip it or anything. Reverse flow cooling simply means the water from the radiator flows through the heads and then into the engine block. In a regular SBC or an LS1, the coolant flows through the block and then into the heads before it goes back to the radiator.

 

WONDERFUL!!!!! so what do i do to make those useful?