i really need help BAD on this one so can u guys please help me.
first off i dont have the stock temp gauge so i just installed a new aftermarket gauge and the seder for it is running to the passanger side of the block just below the headers. i took out my thermostat since it will keep the engine running cooler dureing the summer plus i dont need heat now and i just put on a new rad cap.
Now if my gauge is right my engine temp goes up to about 245F-265F and i think it will go even hotter if i keep driveing. even when its cool outside and im driveig the speed limit it will reach around 265F in 30 min.
i know the coolent is more hot were i mounted the sender but should it get that hot?? the gauge will say the temp is at like 265F but the engine is not overheating and the coolent is not boiling over at all, is this normal? at what temp should it boil/overheat? as u can see im lost on this and need help bad..

could this be related?one time after driveing (stop and go) for about 15min i looked under the hood and there was bubbles(air bubbles i think, because coolent was cold, i put my finger in it and it was worm) the bubbles were comming out of the rubber coolent line at the bottom of the tank (just like a fish tank toy diver with air bubble comming out). Is this normal or does it have something to do with my temp problem,does it? please let me know.
i have a mechanical fan (i can turn it by hand when engine is off so that means i have a clutch fan, right)
could my fan be broke in some way?? i was told that the clutch can brake or something and cause these problems. how do i know if my fan is broke??

i have a tranny cooler if thats makes a diffrence and my rad is from a 305. i do have the air dam under the car, theres no coolent leaks anywere and all the coolent was pre mixed, rad was flushed last year this time. i dont think its a busted head gasket becasue i dont loose coolent, my car dont smoke at all, my plugs look great, is there anything else i should look for??

sorry about this long post i just want u guys to get a clear idea as to whats going on so u can tell me what u could be the problem and what i should do next.

 

Do you have an electric fan? Did you remove the fan switch in order to install the temp sender?

 

no i have a mechanical fan (runs off water pump)

 

Thermal clutch type or an aftermarket?
Hopefully the shroud is there and in tact also.
Also running without a thermostat doesn't always mean cooler.
What condition is the radiator in?

 

First off, without the thermostat being in there, the water in the radiator doesn't stay there long enough to get any 'air-cooling'.
Go to your auto parts store and buy a 180º thermostat. Drill a few small holes in the thermostat to help prevent air pockets.
The temp gauge is in the correct placement, being in the head where the coolant is the hottest. But normally located on the drivers side head.
Replacement clutches for your fan are cheap. Like $20 or so.
If you have air pockets in the cooling system, then it can cause it to overheat.
Boiling point of water is normally like 220º, but when you add 16lbs of pressure to it, it makes the boiling point something like 260º.
If you are driving the car at or around 260, you may not have any head gasket problems now, but you surely will if you keep driving it like that.
Put your thermostat in, replace the fan clutch, make sure your coolant is topped off, and then go from there.

*EDIT* How old is the water pump. also? They don't always leak when they go bad, many times the blades on the impeller rot away, so you get no coolant flow.

 

i already have a new 180 stat so i will put it in tomorrow, i was told by so many people that its a good idea for the summer to take it out.

my fan is stock, so i should replace the fan clutch then?i dont have a clue if its broken or not is there a way i can tell, or do i just need to replace it to find out? and ya u are right i messed typeing, the sender is on the driver side just like my dip stick (70s/350SBC)

oh and I dont drive around when shes that hot, i stop the car around 210F or so to be safe and let it cool. the only times the temp got that high was when i was testing the problem.

About my rad, from what i can tell it dont "look" to bad. oh but last winter there was a couple times were the rad would leak. i though it was a crack in the plastic at first and i was going to get it fixed but the leak would always stop after about 20min of driveing plus. it did this maby 4 to 6 times dureing the winter and its never leaked anything since. could this leak thing have anything to do with my problem? i never did get why it would leak then stop. (though i was lucky lol)

U were saying there might be air pockets in the system, now that i think about it that just might be the cause of my problem. like i was saying in the first post sometimes theres air bubbles in my overflow tank. the air comes out of the hose at the bottom of the overflow tank. could these air bubble have anything to do with air pockets? or am i way off here and the air bubbles are normal?
and i want to get rid of any air pockets all i have to do is flush the system.

 

Its not so much the coolant is hotter by the headers. Its the fact that the sensor is near the headers. You can expect a 20 degree increase on the sensor from the header heat. This means your gauge will give you a false reading (so to speak) of 20 degrees higher give or take 5 degrees etc. As far as air bubbles go try squeezing the upper and lower hoses to burp the system (use a glove, hoses are hot). That may help. Get a thermostat. MAke sure the coolant is circulating well.

 

The clutch assembly is easy to replace. Just unbolt the fan blades from it, and unbolt the clutch assembly from the water pump.
Actually, once you get the thermostat in, it is very easy to eliminate those air pockets. Make sure you drill a few small holes in the thermostat to prevent this from happening in the future, too.
Once the thermostat is in, remove radiator cap start engine, and start adding coolant. top it off and then wait for a little bit. The level will drop, so you can add more coolant in. After the thermostat is open, the level should drop some more, after topping off this last time, it should be full. Put cap back on, let engine run, and make sure overflow is set to full mark.
BTW, a bad radiator cap can also cause overheating. If you decide to replace it, get one with the vent lever on it. That also can help to release air pressure trapped in the system.
You never answered me about how old the water pump is, did you?

 

oh so its cuz the header heat, makes sence. So if i put the sender in the thumostat houseing will the gauge give me the right readings??

i have no idea if the waterpump is new or old thats like the only thing i have not replaced lol.

about squeezing the upper and lower hoses to burp the system, so i just squeez both hoses acouple time? do i squeez them when the car is on/ off,hot/cold? when should i do it.

as for the thermostat (u were saying how to eliminate air pockets, by what u are saying i should have removed them last week then.. unless im getting the wrong idea)
heres what i did so far with the thermostat: at first i though the thermostat was broken because of the engine heating up to much so i got a new one (180 deg) when i took out the old thermostat that i thought was broken it turned out to be working perfect but it was a higher deg so i put the 180 in anyway. I did everything u said "remove radiator cap start engine, and start adding coolant. top it off and then wait for a little bit. The level will drop, so you can add more coolant in" after i filling it all up to were it should be i put a new rad cap on. Nothing changed, temp gauge still climed just as high and fast, it was like i did nothing. I went though the weekend and the monday that just passed i took out the thermostat to see if that would help and it made like no diffrence at all. thats everything i did so far with the thermostat and the reasion why i took it out in the first place. so now what u think?

 

Oh, okay. Now I see the whole picture.
My old 83 S/E wouldn't cool for the life of me when I put in the 355. This is what I did to try and fix it.
1-New lower temp thermostat (still ran hot)
2-New factory type water pump (still ran hot)
3-New Griffin radiator (still ran hot)
4-New clutch for fan (this fixed the problem)
Just my personal experience, but I guess it's either your clutch fan, or the water pump. The clutch fan is cheap and easy, so I'd try that first.

 

The only way to know for sure if the headers are giving a false reading to the sensor is check it with a heat gun. I would say it is reading about 20 degrees hotter IMO. You may be able to move the sensor somewhere else on the intake. Not sure tho. Doesnt matter really as long as you know the gauge is off a little becuz of the headers. Squeeze the hoses once the coolant is circulating (if it does). Take the cap off and get the car to temp. Once at temp the coolant should circulate. Thats one way to tell if the pump is bad. If you have an electrical fan you can see if there is any play in the fan as well (when its off of course). See if that helps. Also, the top of your rad must be at or higher than your intake to cool properly.

 

BTW, what is your timing set to? If the timing is set retard (ATDC), then it can make the car overheat quickly.
Most small blocks like a few degrees advance (BTDC).

 

k i'm going to install a new clutch first thing tomorrow and hope that does the trick. i dont remeber what i set timeing at, i set it so long ago. but i never had a cooling problem till now.

just wonder but what does the clutch do??

 

i did not get around to installing the new clutch but i did get one today (not as cheap as i though 57$) my block is from the 70s so i got a clutch for a 1977 5.7L sbc, all the bolts line up, but there is a slight diffrence. u know the lines that go around it on both side, well the one i got has less because they are gaped bigger. is it basicaly all the same?

oh and i notice the new clutch i just got takes more effort to turn then my old one so it just might be broken.
there is something else i noticed today, when im driveing and im doing a stedy pace of like 60 or so the temp drops, its when im doing stop and go or moveing slow were it burns right up, does this mean anything?? or is it just because i dont have the thermo in yet??

 

Probably too late to ask.
When you got the new clutch, did you get a thermal or non thermal?
If you're running a lower temp thermostat, the thermal type won't help much since it's not set to fully engage until you get over 200 degrees.
The non thermal version stays engaged at lower speeds regardless of temp.

 

nope to late, i did not get a chance to install it today (just moved so unpacking and crap) so ya i can take it back and get the non thermo. im gunna run a 180 stat with drilled holes.
i dont know if the one i got is thermo or not, its down in the car so i cant check right now (the one i got is a stock replacement one for a 70s 350 sbc so prob not im guessing)
so im gettin a non thermo right???


can someone please explain to me what the clutch does?? only thing i figure is it makes the fan more harder to turn.

thanks for the info on the thermo!

 

Stock would probably be a thermal.
It's identified by a coiled spring on the front face. Non thermal has no spring.

 

Hi there,
The Function of the clutch fan is to enable some slippage at higher rpms,this is to prevent some of the power loss due to the engine driving that large mechanical fan,i personally very much like and rate the Moroso Flex Fan,this works on the principal,that at high rpms the blades flatten out causing less drag and powerloss from the engine.I think it would be worth you possibly fitting a small electric fan in front of your radiator.
Do not run without a thermostat,it is very important that the engine reaches its correct operating temperature,both for efficiency,and what alot of people dont realise is that when running the engine at lower temperatures the cylinder wear is multiplied BIG TIME!!Also as the gentleman above pointed out,the water does not have enough time in the rad to sufficiently"cool".It may also pay you to take your rad out and flush it back wards with a garden hose,it may have alot of crap in it.
If you did decide to go the moroso flex fan route ,dont forget to get a fan spacer, toecutterv8.

 

OK, you said it cools at speed, but overheats when going slower and/or in stop and go? The first thing I would be looking at is the fan, which it sounds like you are doing anyway.
It is the fans job to pull the air thru the rad when moving slower as the natural airfllow would not be sufficient as it is at higher speeds.

 

Okay, so did you put the new fan clutch on yet?

 

sry for takeing so long to back to u all and thanks for bareing with me and helping me out. anyway so this is were i am, i decided to upgrade my fan to electrical, so i got a dual fan setup from the scrap yard. that same day i drilled the holes in the 180 stat and installed it then got a compression test done at a rad shop just to make sure, everything is perfect so my head gaskets are good and rad it working great. next day i installed the electric fans and find out they are broke so i take it back and look for anotherone. i could only find single fans>would the electric single fan setup from a 2.8 v6 camaro be enough to cool my engine? then i had the car off the road for a week cuz i changed over insurance and that took some time. so im back were i started except now i dont have the new clutch cuz i took it back to put the money towords the fans.but i figured out how the clutch works and what it does and im almost positive that my clutch is messed. oh and i found out that im suppost to put the temp sensor on my holley intake to get the best reading.
anyway since i dont have the money right now to get a new dual electric fan setup and cant find a working used one so im just gunna replace the clutch. do i need to get a specital fitting from holley for the temp sensor? anyone know the size?
are none clutch fans better at cooling engine?
could i keep my mech fan and put a single electric fan infront of the rad? could i use the single fan from a v6 2.8 camaro with my mechanical fan to??

 

I believe the original reason that GM went with the electric fan was to help take some strain off the waterpump assembly, and with the electric fan only coming on at a certain temp, then you don't have to worry about overcooling the engine (never seen this as a problem on an F-body, though)
As far as putting an electric fan infront of your clutch fan, I don't think you are going to have enough room. You may be able to put it in front of the condensor to make it a 'pusher' instead of a 'puller' fan.
But honestly, my 350 cools just fine with a single electric fan, and my 83 cooled just fine with the new clutch for the clutch fan.
I'd just go with the least expensive route, I guess.
I don't really remember the thread size of the sensor, maybe 3/4"? My gauge temp sender is actually in my thermostat housing right now. If you have the sensor out, just measure across it with a rule, and also any open water ports in the intake. I do know the outside diameter of the nut head on it, is 13/16" (or 21mm), to remove/install it.
If the threaded hole in your intake is too large, any auto parts store should have a threaded reducer to make it work.
Keep us posted....