No t-stat, still runs hot

[andrewjscott]

My car won't stop overheating. I split a hose yesterday and replaced it, now it won't stop running hot. I drive for about 5-10 minutes and then the water starts boiling. I removed the thermostat and it still runs hot. I just don't get it. Any suggestions?

 

[Quasimondo]

I'm sure you checked these things, but I just want to make sure.

What's your coolant/water mix? Where are you filling the radiator from? Did you 'burp' the system?

I know they're stupid questions, but when I had overheating problems, that's the stuff I missed when I was trying to fix my car.

 

[andrewjscott]

running straight water for the summer (can't run antifreeze for drag racing). filled it from the rad cap. As for burping the system, i let it run until there was no air bubbles if thats what you mean.

 

[lil420esi]

yeah i had the same problem when i first bought my car but then come to find out it was a blown head gasket. Anyways to burp the system the best way i found was to take the top radiator hose off and start the car. if you can hold like a bucket or something under the line until you have plenty off water coming out. (just be careful there will be lots of steam coming out). Are your lines really hard after it runs for just a few minutes? if so i would say it is a blown head gasket. even though it may not be real noticable, well hope that helps you a little

 

[Defiant]

I removed the thermostat and it still runs hot.

PUT THE THERMOSTAT BACK IN.

NEVER RUN ANY CAR NEWER THAN 1965 WITHOUT A THERMOSTAT.

 

[andrewjscott]

the thermostat is back in, i had no intentions of leaving it out. Well, nothing i do seems to work, i burp the system (it takes a really long time though) drive around, come back, i'm overheating, after its cool i take the cap off and i'm low on water, but its not leaking, its just boiling off. I have a hunch it could be the headgasket.

 

[CorrupTTalon]

you have nothing but water in there? i dont see how that would be good for a daily driver.. its not a race car yo..

try a 50/50 and see what happens. if youre low then whats your oil look like? you have any in the overflow?

also can you see the water flowing when its running? take off the cap and let it run and watch it for a while.. see if it goes down significantly and see if its flowing.

 

[andrewjscott]

it is nothing but water. It is a race car actually, i autocross and drag and am required to run straight water. It is also my daily driver when i need to drive. oil is clean, water is clean, overflow is full, water flows fine. Only thing is it bubbles a lot, even after i think i've purged the system of air, air seems to get itsself back in there. Thats why i'm pretty sure its a head gasket.

I'm sorta poor being a student, and i'm trying to spend as little money as possible without half-assing it. Should i get the head shaved and pressure tested? It didn't ever even go into the red on the temp guage, as i pay close attention. And should i just get the headgasket or go with a full top end kit.

 

[CorrupTTalon]

well thats my point man, i dont want to take this way off topic but it IS your daily driver, do you drag and autocross daily?............

regardless of whether or not youve gotten it to redline, how long youve driven it HOT will matter and how many times youve done it. untill youre a non poor student i would work on making it the reliable daily that it is, just my .02, not hating.

you can be leaking water into your oil through your oil sending unit as well.. you can over tighten the oil filter and crack the rad cooler inside.. it doesnt have to be your head gasket.. but if you have your stock felt HG on this race engine then yes, im sure its gone by now, its your safety, meaning its gonna go first before youre head and block need to be resurfaced.. in other words i would stop driving it if its overheating. also since youre running straight water its going to be hard to see the oil/coolant mix untill you drain the pan and see if you have separation of water and oil... cause they wont "mix" per se

 

[andrewjscott]

the car is parked now thats its overheating. I havn't driven it except for diagonistic purposes. I am not leaking water into my oil or visa versa. I have drained both and both are perfectly clear. Its an old headgasket so i don't mind replacing it. I'm going with a complete top end gasket kit, i'll see how things go with regard to machine work. The engine is kinda old, would it be worth it to throw new bearings and rings on there while its apart?

 

[CorrupTTalon]

the car is parked now thats its overheating. I havn't driven it except for diagonistic purposes. I am not leaking water into my oil or visa versa. I have drained both and both are perfectly clear. Its an old headgasket so i don't mind replacing it. I'm going with a complete top end gasket kit, i'll see how things go with regard to machine work. The engine is kinda old, would it be worth it to throw new bearings and rings on there while its apart?

yes, if not a complete rebuild then atleast replace the rod and crank bearings along with BS elimination(sure you all ready did that anyways) oil pump if you havent, water pump, timing belt and tensioner..etc... oil pump being at the top of the list.

and im not an expert when it comes to rebuilds but im sure youll want to get the cylinders honed if not bored. im not sure if you can throw a new set of stock rings in without atleast honing and of course measuring the wear, hopefully someone can clear that up

 

[97jestergst]

hey bud, im just curious, i work in a performance shop in saxonburg, PA and i see countless cars every day with overheating problems before you go jumping to conclusions (although it is a dsm ) make sure your heater core isnt clogged with gunk us dsmers tend to do hell to a cooling system! if you can drain ur system and i was you id drain it all get a bottle of coolant system flush, run the gunk remover concentrate from any auto parts store through the system now drain it again and take off all hoses take an air gun blow out the heater core the radiator and the block and all your hoses then put it all back together but you have to blow it out because if there was a part jelled up causing the overheating you just broke loose alot of other gunk and blowing the parts out is the best way to prevent future problems also! it will be like starting with a whole new cooling system and if that doesnt work then think headgasket and even if it is o well cuz then you wont have to worry about any of the other problem in the future!
-Jester

 

[ddavisaf]

hey bud, im just curious, i work in a performance shop in saxonburg, PA and i see countless cars every day with overheating problems before you go jumping to conclusions (although it is a dsm ) make sure your heater core isnt clogged with gunk us dsmers tend to do hell to a cooling system! if you can drain ur system and i was you id drain it all get a bottle of coolant system flush, run the gunk remover concentrate from any auto parts store through the system now drain it again and take off all hoses take an air gun blow out the heater core the radiator and the block and all your hoses then put it all back together but you have to blow it out because if there was a part jelled up causing the overheating you just broke loose alot of other gunk and blowing the parts out is the best way to prevent future problems also! it will be like starting with a whole new cooling system and if that doesnt work then think headgasket and even if it is o well cuz then you wont have to worry about any of the other problem in the future!
-Jester

That chemical stuff actually should only be used as a last resort. It's very harsh stuff and could possibly (I said possibly, not will) cause damage to cooling system components of the electrical sort.

 

[97jestergst]

That chemical stuff actually should only be used as a last resort. It's very harsh stuff and could possibly (I said possibly, not will) cause damage to cooling system components of the electrical sort.

yes you are correct but remember this is why i said to run it through the system before taking anything apart specificly to prevent dumping it onto parts and wires because that would not be very smart and to prevent sensor damage if thats what you meant they usually say right on the bottle mix with so much water to dalude, to prevent electrical damage! and i do recomend it the stuff works wonders for cooling systems trust me i work with it every day!
-jester

 

[andrewjscott]

bad news, tore everything apart and found what may be a crack in the block me, and 2 of my friends are not totally positive thats it, but thats what its lookin like. It's pretty small, i took a picture but it doesn't show enough detail. What kind of options are available short of a new block. Can the cylinder be sleved? Any suggestions would be helpful.

 

[bigblock]

why did you hose split, if it is a race car I'm sure you would keep close eye on your belts and hose ( don't want to break in a race)
is water flowing freely though the radiator or is it restricted
i think you should have try the flush before taking any thing apart
when you fill the system do you use a water hose?
tap water causes calcium and corrosion build up in the radiator always use distilled water
also check the rules my track will let you use additive like Redline Water Wetter, or Problend Icewater. Advance sells both
water boils at 220f the thermo is set to keep the water temp around 195f not much room for error.
also check radiator cap it keeps the system pressurized for every pound the boiling temp rises

 

[andrewjscott]

Hoses all looked fine. I'm guessing it split from the cylinder pushing air into the system and the weakest spot gave.

I checked the rad/h.core and made sure everything flows smoothly, i wish it were that simple.

I have a new rad cap. First thing I replaced

I can run water wetter or other additives. Problem is I'm now stuck with (what looks like) a cracked block, no additive is gonna help that.

 

[bigblock]

Defiant said Take leave the thermo in the if you don't it will keep you car any model with computer in warm up mode
this post is for anyone wondering why take a thermo out would hurt

 

[bigblock]

yea your right, nothing is going help that i missed that post. GOOD LUCK

 

[andrewjscott]

found a pic that does it some justice....


Makes me sad

 

[Defiant]

That's weird. Had it already been bored?

 

[andrewjscott]

not to my knowledge.

 

[p5150]

that definately blows man. Im having the same symptoms right now and im really curious to see what the problem is.

 

[n0c7]

As for letting air out of the system, what I usually do is refill, start the car without the cap on, watch the coolant bubble and give the upper rad hose a few squeezes and as soon as the coolant starts to rise above the overflow mark I turn the car off. I put the cap back on, drive for half a day, let it cool, take the cap off, give it a squeeze and top it off if it needs any more coolant. Never had any probs with this method yet.

 

[blueberry_dsm]

i would say im almost 100% sure its a head gasket. try running a compression test. if its fine, or close, do a cyl leakage test. blow compressed air into the cyl, and watch for air bubbles in the coolant resivour. it could be a small crack in the headgasket. when the head gasket is blown, the coolant cant flow properly. the compression from the cylinders gets into the coolant system and causes the coolant to boil.

here comes some chemistry: when u compress a substance, it automatically gets hotter because the atoms are moving faster due to the smaller amount of room that it has to move. the faster the atoms move the hotter it gets. same with if it gets less compressed, then the atoms are moving slower, because they have more room to cover. then it gets colder.

shane