overheating

[superman3405]

intalled a new 195 degree tstat and not truck in overheating. I had been running w\o one for 100 miles as MFG of motor recomendned. No after intalling truck over heats...any suggestions?

[FLEET72]

Originally Posted by superman3405

intalled a new 195 degree tstat and not truck in overheating. I had been running w\o one for 100 miles as MFG of motor recomendned. No after intalling truck over heats...any suggestions?

• Try a 165* thermostat.

[kirklin762002]

are you sure the thermostat is working try putting it in water on the stove and turn it on and see if the thermostat opens all the way

[superman3405]

tried two more 165 and 200 or something still overheating..I knwo this is a dumb question be you are just supposed to drop it in, spring into the block, gasket on the top then t stat housing right?

[KFreddy]

Yes, spring down is correct.

[Stocker]

Do you have a fan shroud? What kind of fan are you running?

[rage'nrat638]

spell check

better post a picture of your set-up so we can look at it

[superman3405]

spell check huh...

I do not have a fan shroud, the old motor never had one so I did not see the point.
Type of fan I am using...this could be a dangerous answer...a Ford fan. I wa cleaning it after I pulled from my ld engine and one the back it has the Ford logo. I don't advertise that around....
pics attached. 4 Core rad. 16 lb cap with pressure release. I took the t stats out and now is running cool as can be.....

[rage'nrat638]

you really need a fan shroud. it pull's all the air directly thru the radiator. right now your pulling air from every where..

feel in front of the fan clutch the little spring, if its oily its shot and not doing it's job to it's full potential.

does the fan spin real easy by hand? it should have resistance.

also looks like that bottom hose is kinked pretty good. looks like its to long

just a couple thoughts

[Longhorn Man]

ok, now I'm not arguing that a shroud is important... but it's april, and I'm not too far north of him, and it didn't even make it to 70 degrees here today. There is no reason he should be overheating due to the shroud missing.

Now, I notice a lack of rusty green puke all over the engine.... what makes you say it is overheating? Are you boiling over, or going by a dummy light... an aftermarket guage, a 35 year old stock guage?

Who ever told you to run with no T-stat needs shot... don't go there for engine advice.

Are you overheating sitting in traffic... or running down the freeway?
If it's sitting still, or low speeds, but does OK on the road, then you are probably looking at an airflow problem. Yes, the shroud would help, but I would suspect a bum fan clutch. Does the fan continue to spin when you shut the engine off? 1/2 turn or 3/4 turn is ok, but if it spins... then it's time for a new one.
If it overheats when you are running down the road, then you are more likely having a flow issue. (that kinked hose instantly comes to mind) Going 70MPH creates PLENTY of air flow... with or without a shroud, with, or without a fan even. So coolant flow is more likely to be the problem in this case.... kinked hose... lower hose getting sucked shut, bad water pump, clogged rad (although yours looks newish)

[superman3405]

Longhorn Man
I am ony over heating with the thermostat. Without on I am fine. does not get hot at all

I overheated just minutes after putting it in, go about 1 block away from the house here and the temp gauge was HOT....I have a new temp sender coming out of the side of the block, wire going to temp gauge. Yes the rad is new the fan does spin all the way..I just went of to look at it. I will go pick a new fan up with clutch tommorrow and seet what that does to it.

Now...what significance does the clutch play on the fan....why does the truck need the thermostat IF it runs without one. I mean if it is going to get hot, it's going to get hot without on right....I have never understood these things.
I remeber asking my stepdad these questions when I was 16 with my first c-10, and his answer was, "Son that is just the way it is",

[bryanw1968]

I think the reason you overheat when you put the stat IN is because you have a water flow issue, ei; kinked hose like everyone else is mentioning.

With the stat out you have just enough flow to make it work. However, as summer comes on that ain't gonna cut it.

When you run w/o a stat water goes through the radiator so fast that it's not in there long enough to cool the water down. I would make sure your fan clutch is good, install a shroud and put a good stat back in. I'm running a Mallory 180 degree. It holds dead on 180.

Also, I didn't notice but are you running an overflow can? If not, as the system gets hot and purges it will spew out water/anti-freeze and then draw back in hot air. That hot air will make things worse.

Good luck,
B

Originally Posted by superman3405

Longhorn Man
I am ony over heating with the thermostat. Without on I am fine. does not get hot at all

I overheated just minutes after putting it in, go about 1 block away from the house here and the temp gauge was HOT....I have a new temp sender coming out of the side of the block, wire going to temp gauge. Yes the rad is new the fan does spin all the way..I just went of to look at it. I will go pick a new fan up with clutch tommorrow and seet what that does to it.

Now...what significance does the clutch play on the fan....why does the truck need the thermostat IF it runs without one. I mean if it is going to get hot, it's going to get hot without on right....I have never understood these things.
I remeber asking my stepdad these questions when I was 16 with my first c-10, and his answer was, "Son that is just the way it is",

[70C10Toejam]

the clutch on the fan is themal. when it gets hot, it engages and drives the fan at the same speed as the water pump. when it is cold, it does not spin as fast, helping the engine warm up. also, at highway speeds it lets the fan "freewheel" when, as stated above, normal airflow is enough.

the thermostat holds coolant in the engine until it warms up to operating temp. then it opens an lets in cooler coolant to keep the engine from gettng to hot. an engine that does not get warm does not run right, newer ones will run rich because the comp. thinks the engine is still cold.

not running a thermostat keeps the coolant from staying in the engine long enough to absorb heat properly. it also does not let the coolant stay in the radiator long enough to cool. not using a stat can cause overheating just because the coolant cant cool down in the rad.

hope this helps.

[superman3405]

thermal clutch or non thermal clutch, regular fan or flex fan???

[70C10Toejam]

my understanding, flex fans are intended for use with spacers/no clutch, thats why they flex. flex at high speeds, less resistance, bend back in at low speeds for increased air flow.

thermal or non-thermal clutch, don't really know there. not sure what a non-thermal clutch is. the main reason for the clutch is increased flow at low speed and less resistance at high speeds.

i didn't see it in the pic, but i would investigate the reported kinked lower hose. could be causing too much restriction with the stat.

[67 cst swb]

Lower hose I would suspect is your problem.......!
with the restiction of that lower hose, and the restriction of a thermostat... your not flowing enough to cool... BUT, with no thermostat, your only restriction is the hose,... which is why I suggest a new lower hose... PLUS way cheaper than a fan...
Also... get a fan shroud, if not today,... someday soon...
Also II... NEVER, NEVER, NEVER... (ok I'm anal about this) never run a flex hose... Just for reasons like this, they get old and weak and fold over an cause problems... I've seen old street rods with them... It makes me less mad, but still hate it...

[superman3405]

okay guys, new lower hose, new fan, new themostat, new antifreeze..
problem ...the truck gets close to the hot mark and then the tstat kicks in cooling it down. Then back to close to hot, them cool again. suggestions??

[Crank]

Fan Shroud! Your water pump I'm sure is good, but you dont see any coolant coming out of the weep hole do you?
Brandon

[superman3405]

nope no coolant leaks anywhere, I will see if I can't round up a shroud somewhere.

[cdowns]

my normal advise before changing or buying anything is to get an accurate thermometer and take the temp of the fluid inside the radiator before you assume that your temp gauge is anywhere near accurate// i've seen parts changers go thru hundreds of dollars when a $5thermometer confirmed there wasnt an overheating problem

[Tx Firefighter]

Relax on the fan shroud. I run my truck in 100+ degree Texas heat with a 3 core and no shroud. That's throwing parts at something without looking foe the root cause.

Sounds to me like you're getting an air lock when you install the thermostat. Open the thermostat by hand and insert two aspirins into the gap to hold it open. Now, install the stat and fill the system with coolant. The aspirins will hold the stat open, allowing air to burp through it. As the water begins to flow, the aspirins will dissolve and go away. As an alternate, I usually drill a real small hole in the stat where are bubbles can flow though. Lots of modern cars have little bleeder holes in the stats for this very reason.

Also, get rid of that god forsaken lower hose. Those flex hoses put an incredible strain on the radiator bung because it's always trying to straighten out. Get a molded hose. Your expensive radiator will appreciate it.

[superman3405]

Originally Posted by Tx Firefighter

As an alternate, I usually drill a real small hole in the stat where are bubbles can flow though. Lots of modern cars have little bleeder holes in the stats for this very reason.

where in the stat will the hole go, in the outer ring?? And this will not hurt anythign in the long run of things will it??

[67 cst swb]

let your truck idle (in park of coarse) with the rad. cap off... watch to see if your coolant starts circulating. topping it off as the leval goes down. this usually takes about 15-25 minutes to complete... once everything looks normal (levels, flow, etc) re-install cap.... then turn off engine.... let stand for 30min to 1 hour... take off cap, top off (if needed)... re-install cap... start and drive... it should push some coolant out overflow tube... (normal) that also should get any air bubbles out. you have not pressurized the system so, you should not overheat or cause a air pocket...

ALSO... you are running a 50/50 mix of anti-freeze to water, right? and your not using dex-cool I assume?

[superman3405]

you see that is why this forum is GREAT!! so much knowledge at one place. Kudos to you all!!!


Lower hose is gone, replaced with molded hose. I ended up getting a new fan on today to get rid of the only ford part on my truck.
I will try the suggestions thru the course of the week and let you all know what happens. I ain't putting it on the road until it will idle at a normal temp.

[jhow66]

You are putting themo this way aren't you?