170 running hot

[mississippiboy]

i have a 170 in my bronco and at idle it runs about 170 but when i drive it will rise until i stop and temp will fall back to normal .new water pump ,radiator is not the correct radiator but just had it boiled out .new thermostat ,no shroud . could no shroud cause this problem.

 

[Skiddy]

yes a shroud will help a lot. how hot is it running?

 

[mississippiboy]

it will continue to rise until i go back to idle .

 

[Timmy390]

Odd as when you drive you should have MORE air flow than at idle. 170 isn't that hot IMO as my bronco with shroud runs 200 with stock rad. I have a 180 or 190 in mine can't remember it's been several years since I put it in.

How hot is it getting?

New water pump? is it the correct pump? Some are reverse rotation.
What type of fan?
Check your temp sensor. Cheap and easy to replace.
Adding a shroud is always a good idea.

Tim

 

[Justafordguy]

I would think it would get hot at an idle/stop if it has no shroud. Doesn't sound like an airflow problem. I would think stuck thermostat or wrong water pump. maybe loose water pump belt?

 

[Bronco Junkie]

A shroud is a good idea....but you seem to have the opposite problem that a shroud would solve. I say check/replace your thermostat.

 

[mississippiboy]

im on my second thermostat.i even took it out to make sure i didnt put it in backwards.as to how hot its running it will peg out if i let it .

 

[Bronco Junkie]

180 thermostat?? Then my next guess would be your water pump.

 

[mississippiboy]

when i bought it i went and put new water pump on it because it was running up around 210/220 but it was much cooler weather than it is now .yes a 180 thermostat .the only thing that is not a direct replacement is the radiator .i just want to exhaust all my options before i purchase a new radiator, i have 80 bucks in this one now

 

[Timmy390]

i went and put new water pump on it because it was running up around 210/220 but it was much cooler weather than it is now

New don't always mean good and good don't always mean new. Maybe you got a reverse flow water pump by mistake. Parts counter guys have made mistakes before.

Could maybe be air in the system? Pump is cavatating at speed?

I know this will sound crazy but it happen to me. Where did you buy the Tstat and what brand? I had an over heating issue on a brand X car and after 4 new Tstats I was told to buy a NAPA one. Well, I called BS but did it anyway. Problem went away after I put it in. No BS the car still has that Tstat in it now and it never gets hot even in 110 temp with A/C running full. Also, check the Rad cap. If it's junk, water will not flow correctly.

Tim

 

[mississippiboy]

how would i check for a reverse flow pump

 

[Bronco Junkie]

It just seems to me if it was your radiator it would be hot all the time and get cool when you drive it because there is more air flow. The fact that it cools down at idle is strange.

 

[mississippiboy]

Yes i agree. It is driving me crazy

 

[Timmy390]

how would i check for a reverse flow pump

I would pull the one you have off and take it to the parts store you bought it from and ask to see another pump. Make them look it up in the computer and bring it out to you. Then look at the impeller on both. See if the vains are pointed the same way.

Maybe someone else knows of a better way?

Your lower Rad hose new or old? Maybe it's colapsing when the pump is up to speed?

It has to be about water flow not air if it cools better at idle than driving.

JMO

Tim

 

[73stallion]

the person who bought our ranchero had it overheat not far from here on his drive home. turned out the coil was going out and causing it to overheat. can't explain it, but he changed it and made it home. it was a 170 also.

 

[broncnaz]

170 at idle is fine anything below 240 while driving is fine as well. Your not getting all that hot unless your puking water out. While a shroud will help 6cyl broncos didnt come with shrouds so if its running real hot I'd say radiator as well. I'd get it rodded out just to be sure. Might want to flush out the block real good as well. as at idle the engine is doing no work so not a lot of heat is made but once driving the engines is working so temp will go up.
I doubt you have a reverse flow water pump I dont think they even make one for a 170.

A few other things could be causing the high temps as well to lean jetting, timing off, large overbore pistons, cracked block or heads, bad head gasket, bad radiator cap ect.

 

[mississippiboy]

i still have my old water pump and it appeared it had been on for quite some time the temp was rising when i had it on but not as much as now ,that was back during cooler weather and yes i have new top and bottom hoses .have not give much thought to radiator cap it would be a cheap try.im gona try to check for air in system .

 

[mississippiboy]

I think i found my problem .put my truck on jacks in my shop and was letting it run in 1st gear and temp started rising ,while banging my head on the steering wheel i noticed if i put the weight of my foot on the clutch pedal the temp would fall so i felt it was a ground problem ran a temp wire from my neg. Battery post to inside the cab and it fell back down to about 170 took a run up the road and it stayed steady .

THANK YOU GUYS FOR ALL THE HELP !!!!!!!!

 

[Bronco Junkie]

I think i found my problem .put my truck on jacks in my shop and was letting it run in 1st gear and temp started rising ,while banging my head on the steering wheel i noticed if i put the weight of my foot on the clutch pedal the temp would fall so i felt it was a ground problem ran a temp wire from my neg. Battery post to inside the cab and it fell back down to about 170 took a run up the road and it stayed steady .

THANK YOU GUYS FOR ALL THE HELP !!!!!!!!

Sweet...glad you found that. What a freak thing...damn Ford wiring.

 

[half cab]

Very interesting read right here for sure!!