302 reaching 230F

[72bahama]

I went ahead and used the thermo gun, I had the car idling in the garage for about 40 mins for it to reach 225F with the hood open; once the hood is closed it starts to climb.

With the engine reading 225F, the radiator was ~193; top radiator hose ~193, and bottom radiator hose was ~206.

 

[Johnnyb]

I went ahead and used the thermo gun, I had the car idling in the garage for about 40 mins for it to reach 225F with the hood open; once the hood is closed it starts to climb.

With the engine reading 225F, the radiator was ~193; top radiator hose ~193, and bottom radiator hose was ~206.

Sounds to me like maybe a gauge issue. Presuming 190 thermostat. Original EB gauges? Could be sender, voltage regulator, gauge itself. Does oil pressure look high as well?

It's odd, though that bottom was hotter (on reconsideration). Need to monitor under load, bottom should be cooler with t-stat open.

When I ran original EB gauges, I always had an aftermarket oil and WT gauge. Problem with aftermarket WT gauge is it is hard to keep the factory sender position and add an additional sender, both in coolant flow. Best case, use a T-fitting on the heater outlet, but whatever sender is in the T-fitting will only have flow if the heater is on.

-JB

 

[Timmy390]

Sounds to me like maybe a gauge issue. Presuming 190 thermostat. Original EB gauges? Could be sender, voltage regulator, gauge itself. Does oil pressure look high as well?

When I ran original EB gauges, I always had an aftermarket oil and WT gauge. Problem with aftermarket WT gauge is it is hard to keep the factory sender position and add an additional sender, both in coolant flow. Best case, use a T-fitting on the heater outlet, but whatever sender is in the T-fitting will only have flow if the heater is on.

-JB

I was thinking 185 stat as the rating is the "start to open temp" and generally takes another 12 degrees to fully open.

X2 on the mechanical gauge i.e. aftermarket. I don't eve have my dash gages hooked up. I run a mechanical gauge for water temp, oil pressure and volts. As a test, just add the mechanical in place of the stock unit. That will give you real numbers.

Tim

 

[72bahama]

Will take a look at things mentioned above, not stock gauges, truck came with the Dakota Digital gauges. I am unsure of the thermostat being used, from what I can tell I would need to remove it to check.

Oil pressure seems normal

 

[Johnnyb]

Will take a look at things mentioned above, not stock gauges, truck came with the Dakota Digital gauges. I am unsure of the thermostat being used, from what I can tell I would need to remove it to check.

Oil pressure seems normal

I love my Dakota digital and so far they have proven to be very accurate.
I would say: take it on a run and try to recreate the 230° condition and then shoot it with the IR gauge again.
To my way of thinking, the top hose should be hotter than the bottom hose if the cooling system is functioning properly.

-JB

 

[73azbronco]

Hey everyone, took out my Bronco today with a 302 engine for about a 30 minute ride and the temp reached 230F until I decided to shut it off and let it cool down. I purchase my truck from ClassicFordBroncos.com and they are telling me that due to the truck having A/C it will run hotter due to the condenser in front of the radiator. However, weather has actually cooled off here in Florida so I would have thought I would have seen this during the peak of summer. They are also telling me 230F is a bit high but not harmful/bad. I did not test to see how high it would climb to but seeing other peoples numbers on the forum, I know it's high and something is up.

1. Does this make sense?
2. What temperature should I not let it get to?
3. Anything I should check specifically? (Coolant is full)

Yes
220
does it overheat with AC off?

Did seller even offer to look at it?

I am not a fan, no pun, of flex fans. seems a regular ford metal fan on a clutch could work. I think i use the same shroud but stock radiator. On a 347, in az, but no air,

If it does not boil over, your radiator cap is ok, you have other issues, like not enough airflow caused by condenser placement. Water pump? All air burped out of system? Do a pressure check to see if you have an internal leak into engine, ie, bad head gasket.

Is it fuel injected, throttle body? Carb? How old is motor, overbore?

Look, this is a ford v8 from decades ago, not a v6 VVT from jeep which can see 235, but use some pretty darn expensive coolant and computer wizardry to do that. It should at best be hitting 220 on a hill, maybe touch 230 full power but how often do you do that in Florida? Particularly if carbed, you will boil the fuel in the carb at that temp.

After you drive and it gets to 230, does it cool back down at idle stopped or stay really hot? Cooling after stopping indicates an airflow problem, staying hot indicates to me, a worn out motor. Your normal prestone can handle 230, much over that and it will boil over dramatically.

The broncos they sell, go for over $200,000, are you saying for that price they state, you cant use air when its hot, because it will overheat? I would be riding them with all your might selling you a bronco that gets that high.

 

[73azbronco]

Here are some pics, it won't let me upload so had to use links

https://ibb.co/9w58XHP

https://ibb.co/9pYdjZD

https://ibb.co/gvbQpDz

https://ibb.co/YL9nwZh

You need to pay to become a contributor, price of free advice, sorry.

 

[72bahama]

Yes
220
does it overheat with AC off?

If it does not boil over, your radiator cap is ok, you have other issues, like not enough airflow caused by condenser placement. Water pump? All air burpoed out of system? Do a pressure check to see if you have an internal leak into engine.

The broncos they sell, go for over $200,000, are you saying for that price they state, you cant use air when its hot, because it will overheat?

I will see how it acts with the A/C off, haven't tried that.

I purchased a used one from them (2.5k miles) and not a coyote so it was much less of a cost but I figured they were reputable so it would be a reliable truck and its turned out to be kind of the opposite for the price I paid. I have direct contact with their "master tech" and he is telling me 220 is normal and 230 is not bad lol

 

[Timmy390]

The "master tech" is somewhat right.........220 is normalish for EFI as most systems run a 195 stat. Summer heat in Arkansas pulling a utility trailer and some stop and go traffic....yup, I hit 220 but my ECM controlled fan kicks to high at that point.

230 isn't BAD but it's not good IMO. That's just not a proper normal operating temp while just driving along. My 69 390 Mach 1 has hit 230 during the summer in 100 degree heat and sitting in traffic and it always worries me.....pucker factor starts to kick in and I pray for the light to turn green so I can get moving.....

OEM systems all run electric fans and when the A/C is on, the fans are always on HIGH......

Tim

 

[72bahama]

The "master tech" is somewhat right.........220 is normalish for EFI as most systems run a 195 stat. Summer heat in Arkansas pulling a utility trailer and some stop and go traffic....yup, I hit 220 but my ECM controlled fan kicks to high at that point.

230 isn't BAD but it's not good IMO. That's just not a proper normal operating temp while just driving along. My 69 390 Mach 1 has hit 230 during the summer in 100 degree heat and sitting in traffic and it always worries me.....pucker factor starts to kick in and I pray for the light to turn green so I can get moving.....

OEM systems all run electric fans and when the A/C is on, the fans are always on HIGH......

Tim

This seems to be what is happening to me. I should have put it together sooner, but when this first happened I was waiting for my son outside his school for about 10-15 parked with the A/C on. I just took the truck out again, and it is running between 199-205; if I stay not moving it will continue to creep up to the 230F I first experienced but if I am moving everything seems fine.

Is this expected for this engine/truck? my 302 is carbureted.

 

[73azbronco]

you therefore IMO have an airflow issue if it creeps up at idle. Or worn out motor.

As stated, 230 will get the carb boiling so I could expect some vapor locking while driving.

A carbed 302 is made for 180-190. Most run 195 as that also makes an EFI happy, and most engines are built rebuilt with better tolerances than what came out of a non computerized factory 50 years ago. c0lder than 190 can also cause excess cylinder wear. 230 in my 50 year expert mechanic engine building engineer opinion, 10 degrees to hot. It will work, but be ready for the vapor lock and such.

 

[Timmy390]

Sure sounds like bad airflow. Adding the condensor adds airflow restriction as in the thickness the fan has to pull air through. At idle the fan spins at one speed vs. Moving its spinning faster and has forced air too.

Air will take the path of least resistance. Try the $1 bill test. At idle see if a $1 bill will stick to the radiator or in your case the condensor. It should stick.....if not you found the issue.

Tim

 

[Wild horse 75]

Couple things I can think of. You might want to reduce the spacer behind the fan so it’s a bit further out into the shroud. You may not be able to though due to clearances I can’t see from you picture. I would also look at closing off the gap between the grille and rad support to force all the air through the rad. Then you’ll want help get the air out from under the hood. So either a cowl hood or inner fender vents. A reading of 225 on the gauge will read only a bit over 200 on an infrared outside. One thing I noticed is you said your upper hose was cooler than your lower hose. That shouldn’t be unless you’ve got a reverse flow pump. Your upper hose should get the hot water out of the engine and your lower hose should be returning it. The best place to check is right at the thermostat housing on the intake and the housing or right on the intake where the sender is.

 

[73azbronco]

whats the story on the engine? new, rebuilt?

 

[m_m70]

Where's your timing set??? Not sure if anyone's brought that up yet....

 

[nvrstuk]

This seems to be what is happening to me. I should have put it together sooner, but when this first happened I was waiting for my son outside his school for about 10-15 parked with the A/C on. I just took the truck out again, and it is running between 199-205; if I stay not moving it will continue to creep up to the 230F I first experienced but if I am moving everything seems fine.

Is this expected for this engine/truck? my 302 is carbureted.

NO that is not expected for a 302. Your dealer or head tech is feeding you a line of crap. If you have a 185 deg t-stat your engine should run at 185deg or within a deg or two. 302's are relatively easy to cool even when 100+ deg, even with AC. You have answered the question we all needed to see. HP makes heat. 302's are hundreds of hp less than other engines guys here have on this list and they cool fine.

Here's what you told us:

When parked it creeps up and get's hot like you said up to 230deg.

When cruising the temp stays at 199-205deg.

Here's your answer:

Airflow. When parked you are relying on your fan to pull adequate air thru the rad to cool it.

When cruising the speed which you are travelling PLUS the fan combined draws enough air flow thru the radiator to cool it as you said.

The obvious answer is you need to increase air flow when parked so enough air is flowing thru the radiator to keep temps at your t-stat temp- not above it!

So, back to your radiator brand and type, fan design and type and shroud, design and type.

SOOOoo many questions here and since you are relatively new to this rig you might not know most of the answers- no offense intended in any way.

1- age of radiator (& engine) and brand (stock size???) cap has already been addressed

2- type of fan. You obviously need a fan that pulls the MAX amount of air possible thru two coolers essentially. So you need a stock EB 7 blade mechanical fan setup in the correct shroud and spaced properly or another great option that many here choose is to put an Explorer serpentine system on. Clutch fan, works really well. Try a search here on CB. Might be more than you want to tackle but it has many benefits I'll let others type out.

3- shroud. So important. Has to fit right, be sized properly and is more important than most people realize. It will make the fan be as efficient as it can be and in your case it NEEDS to be working 100%!

There are several ways to fix this but it depends which way you want to go.

Other things-
Already mentioned but the temps you got for upper and lower hose aren't what they should be. Lower should always be cooler than upper. We need to know physically where you got those readings.
Timing can also affect your cooling but you are fine at speed so I am guessing at this point that your timing is ok.

 

[73azbronco]

I also want to hear more on the motor, age, timing etc. Vacuum reading.