My overheating journey never ends

[metal1]

had similar issues with my stock 289 ,before me someone had installed a hayden flex fan but it was only 14"in diam fought everything not even thinking diam swithed to a 18 " 6 bladed fan that I had hanging on the fence , tweaked it a little to keep it off of the crank pulley and off of the shroud .no more heating problems

 

[mduenas]

We're just re-hashing all the same things as before it sounds like.
Maybe you should tie this into your other threads instead of starting another one. I know it's good to get fresh ideas, but it's also good to be able to go back over what was already thrown into the ring to make sure we're not duplicating the effort.

I don't remember if you said you confirmed the gauge readings or not.
I doubt it's a thermostat issue, because it reacts so quickly to going faster. Does it also cool down just from reving up the engine but not moving?
I doubt that it's a thermostat issue also because it does not heat up when you have the hood open. That's a classic air flow issue. Not even coolant flow, just air flow.

If you can pull a piece of cardboard up to the front of the radiator at idle, you're pulling enough air for most engines to run cool.
Sounds to me like a tuning issue. Have you advanced the timing a few degrees just to see what's going on? I know we talked about it before, but I don't remember what you said you did.
If you're having issues with pinging at the higher timing advance settings, disconnect the vacuum advance temporarily and see if that helps.

How old is the distributor? That one of the new parts you mentioned?

Maybe at least post links to any other discussion threads you have going on to make it easier to reference what's already been done.

Thanks

Paul

Hey Paul, good point, I had added all previous threads about my cooling the my top post.

I have confirmed my gauge readings and they are accurate.
I have not yet advanced my timing yet, as I had a friend of mine check the timing and was told it s good, I can't remember what it is set up, and I will check. It is a new distributor, almost everything on the truck is new, as I had a 351W with major cooling issues in the same truck. So I pulled it as I was told the cylinder walls were too thin, and added a rebuilt 302.

 

[mduenas]

Were you running the A/C?

Define "cooler out"

How hot is it getting when it's "overheating"? Mine runs 210ish all the time in he summer.

Isn't that Ron Davis Radiator thicker and more dense than stock?

Just thinking thicker and more dense with an A/C coil in from of it would equal low air flow.

Tim

It got to 230 before I pulled off the freeway and turned the motor off to let the truck cool down.

instead of 85 out, it was around 70.

Yes the ron davis is thicker than stock, and in combination with the ac condenser that is a lot of material to move air through, I have thought about that, and wanted to add a pusher fan, but I am not sure that is the answer. As I do not want hood pins, and not sure what to do with the hood latch and the safety release to allow for the room of a pusher fan.

 

[DirtDonk]

Timing being "good" is not good enough when you're hunting down a problem that could be related to timing. Some engines were specified from the factory to have 4° BTDC timing, but still ran better on 12!

If you don't have a timing light yourself, don't wait for a friend with one. Loosen your distributor hold-down bolt and twist the distributor yourself.
Turn it clockwise 1/4" at the cap and lock it back down. Drive it and see how it runs.
If it runs ok and does not ping or make otherwise rude noises under load, turn it some more. Rinse, repeat...

As you advance the timing your idle speed will go up as well. As this happens just lower the idle with the idle-speed screw and then tweak the idle-mixture screws a tiny bit to keep the smoothest possible idle.

If you hear pinging under heavy acceleration, back the timing down a notch and leave it there to see how it runs. If it still runs hot we can go down another path. But at least you'll have eliminated one very common reason for engines of all brands running hot.

Paul

 

[mduenas]

Timing being "good" is not good enough when you're hunting down a problem that could be related to timing. Some engines were specified from the factory to have 4° BTDC timing, but still ran better on 12!

If you don't have a timing light yourself, don't wait for a friend with one. Loosen your distributor hold-down bolt and twist the distributor yourself.
Turn it clockwise 1/4" at the cap and lock it back down. Drive it and see how it runs.
If it runs ok and does not ping or make otherwise rude noises under load, turn it some more. Rinse, repeat...

As you advance the timing your idle speed will go up as well. As this happens just lower the idle with the idle-speed screw and then tweak the idle-mixture screws a tiny bit to keep the smoothest possible idle.

If you hear pinging under heavy acceleration, back the timing down a notch and leave it there to see how it runs. If it still runs hot we can go down another path. But at least you'll have eliminated one very common reason for engines of all brands running hot.

Paul

I have fitech installed, does that change anything with the timing? Just to be certain before I run through this.

 

[DirtDonk]

I have fitech installed, does that change anything with the timing? Just to be certain before I run through this.

It changes many things, but instead of being a reason to hold off, it's even more of a reason to experiment with your ignition timing.
Unless the computer is controlling the timing in your case, it in no way changes the fact that every engine responds differently to different tuning specifications and with each change you're farther and farther from having anything that used to be stock left over to hold you back from experimenting with yours.
There's no way to tell your "timing is good" like the mechanic said, because there is no known "good" point until you experiment. The stock parameters by the original factory designers (hoping to hold a middle ground for the masses by the way) are no longer valid.
Instead of just checking and confirming timing, he should have changed it a bit to see if you liked the change. You were there to help with a problem, so he should have tried to make small, incremental changes to see if something improved.

Even when totally original all of our engines almost always benefited from fiddling with the timing.
Same here in your current situation. Fiddle with the timing or you'll never know if it was part of the problem or not. There is nothing that is etched in stone except that nothing is etched in stone.
If it doesn't help, then at least you tried, and ruled out one possibility. But if it does help, what have you lost but some of your stress and pain.

You have to experiment with timing. There's a member on another forum that sets his initial timing at 18 degrees! It's harder to start when hot, but he says it runs so much better than it ever did. That's roughly 10-12 degrees advanced from the factory recommendation. Changing yours 2 degrees at a time to see if anything improves is not going to melt your cylinder heads.
And with the computer controlled EFI setup, it should be able to adapt to different readings on it's oxygen sensor(s) to make best use of the new settings.
So are you letting the FiTech unit handle the timing for you?

If you get a timing light as a tool of experimentation, that is even better in that at least you know where you are in plain numbers. But in lieu of a timing light, just twist the thing until it complains. Then back off a tiny bit.;D
I normally don't say that stuff to someone who's not comfortable messing with engines and may not know what to look or listen or feel for. But you're now on the second page of the fifth thread about your overheating issue and have not really determined anything and have obviously held off in implementing some of our recommendations now for, as near as I can tell, at least two months.
So make some changes. You've got to start somewhere!

Paul

 

[75Bronc]

How is your O2 sensor installed? If it is installed incorrectly (like on the outside of a bend) it could potentially cause it to run lean/hot.

 

[DirtDonk]

The reason I'm on so much about the timing and tuning is that you've got almost everything physical that you can improve upon already handled. At least in the cooling system itself. Super water pump, super radiator, super fan, and most everything else except for relieving the air out of the engine compartment with panels and ducting.
You still have some physical modifications that you can make (ducting and venting) but those take some extra commitment (other than the air dam that is) because you're modifying existing stuff on the Bronco.
Since changing the engine timing is EPICALLY EASIER than replacing body panels, it's the most obvious place to start.

Did you ever get a shroud installed? While not the cure-all that we'd like, it's certainly a cog in the wheel of cooling.
So are air ducting aids such as the air-dam that goes over the top of the grille and core support to close that gap. Nickeboy has already mentioned that it helped in his case. Others have had similar results. I'm using one because I like the tool tray aspect (always have) and wanted it for it's effect on efficiency even though I've never had a heating issue to cure.
I don't remember reading if you tried that or not.
And instead of buying a pre-made one as an experiment, you could try blocking the air flow yourself first. If it doesn't help, then you don't need to spend 75 bucks (Radiator Air Dams but if it does, then it's a worthwhile product.
Louvers in the hood are not to everyone's taste or willingness to cut a body part (WH Hood Louvers but they do work when you don't want to drive around with your hood strapped to your roll bar!
Same for the inner fender mesh Ventilators (Fender Vents for evacuating hot air.
These things are on the market for a reason. Broncos run hot, and some engines are harder to cool than others.
Sometimes you have to go for the gold and do everything. But easier/cheaper stuff first is my motto. Keep experimenting until you narrow it down.
In your case, you're actually lucky that it is repeatable and consistent in that it's only at slow speeds. How quickly it cools after speeding up indicates to me that the cooling system itself does not lack the capacity. Just the efficiency, or that it's being overloaded under certain narrow circumstances.

The next thing I'd do then, as an experiment that doesn't cost anything, is remove the hood. I think we may even have talked about that in another thread. You already know it does not overheat when sitting with the hood open, so you need to pull the hood and actually drive it in the heat to see if that holds true under tougher conditions.
Back in the seventies and eighties we used to see Broncos all the time on the hard trails running with their hoods as "sunshades" strapped to their roll bars. For them it was the only thing that would let them run normal temps while on the trails.

Do you have headers? Are they ceramic coated or at least wrapped with heat barrier? If not, they should be.

There's always more to do.

Paul

 

[DirtDonk]

Good suggestion 75Bronc.
Have you run the numbers on your FiTech readout mduenas? Do you know what the AFR's are running under different circumstances?

Paul

 

[mduenas]

75Bronc,

my O2 sensor is just on the on the outside of a straight portion, right after my shorty headers connect to my exhaust (I have to run shorties due to the 700r4)

Dirt Donk,

I decided to pull my thermostat again, to make sure I put the right one in, just put a FlowKooler Robert Shaw 196 Thermostat in 1.5 weeks ago, pulled it out, and the barrel is completely scratched up, as if it has been sticking, I replaced a 180 thermostat that was originally in there. So today I just put another FlowKooler in there, hoping the first was just bad. Next, I used a radiator cap tester to test the radiator cap I had just put on, bought from wild horses with a diode in it about 1 month ago, and it failed the test. I put it on and ran the truck and I never built up pressure either, so I just went to oreilly and got a 13psi cap and the truck built pressure immediately and got to operating temp within 2-3 minutes.

I have taken all the advice I can, Yes I replaced my shroud, yes I replaced my radiator, yes I put in a bigger fan, yes I sealed every gap around the radiator, I even put cardboard air dams in a few days ago to see how the truck would run, just to see if I needed the wild horses stainless steel dam.

I pulled out my timing light today and checked the timing, I had a very hard time reading the degrees with it, but it seemed to be at 11 degrees, I advanced it ever so slightly both ways, but ultimately put it back to its original spot as it seemed to run the best from what I could hear and feel, although I am no expert.

I am going to run a compression test to see if I have a head gasket leak, I got one of the kits that the water will change colors if carbon is detected in the coolant.

As for the FiTech, I have 0 idea on how to read the numbers, or what even the AFR's are.

I let the truck idle for a whole after I just replaced my thermostat again, on an incline, with a funnel to get all the air out. I am just about to close it all up and take it for a drive. While the cooling system was not under presser (cap was off) The temp would hit 200 or 203, then drop to 195 (thermostat setting) and then climb and drop. So for right now, all seems to be better, or I hope, I will update in a bit. Any help reading the fitech will be appreciated.

It is not that I was not going to do everything that was suggested. It was that I hadn't had time to spend a full day knocking everything out at once, I have a newborn, going through a remodel on the house and work 10 hour days. Just needed a day to run through everything and the Bronco is my daily driver. Thank you so much for the help!

edit:

grabbed my old thermostat just to test it, and realized it was a 160! It opened in boiling water at 160, but not fully until 180, and it also opened on an angle. The previous KoolFlow one, that was a week old that I just replaced, opened, and then wouldn't close.

 

[blubuckaroo]

This overheating stuff really isn't that mysterious or difficult to fix.
If you can't keep your engine in a proper heat range with stock components, you've got other problems. Quit throwing money at it with super pumps and radiators. You've got a thermostat, cracked head, or gasket problem.
I've got all stock stuff, and can sit in traffic or run 75 on the freeway on a 110* day with the A/C on and it stays around 200*.

 

[mduenas]

This overheating stuff really isn't that mysterious or difficult to fix.
If you can't keep your engine in a proper heat range with stock components, you've got other problems. Quit throwing money at it with super pumps and radiators. You've got a thermostat, cracked head, or gasket problem.
I've got all stock stuff, and can sit in traffic or run 75 on the freeway on a 110* day with the A/C on and it stays around 200*.

I got a rebuilt motor from west coast broncos, so I guess I’m hoping he head isn’t cracked or bad gaskets. I have nothing leaking.

I can drive with 0 issues on a hot day with ac, it is traffic that is the killer. I am going to check if I have a bad head gasket tomorrow, how do I check for a cracked head without tearing it apart?

 

[pcf_mark]

If your issue is isolated to idling then you have an airflow problem. You need to understand how the air is flowing into and out of the radiator core. Is there any way the air is sneaking around the core? For example is there a big gap around the edge or does it meet the rad support very closely?

Is your fan in a proper close fitting shroud? Is the shroud sealed to the core? Do you have a lift that may have moved the fan away from the core? Is it the stock fan with a clutch? Have any pictures?

 

[blubuckaroo]

I got a rebuilt motor from west coast broncos, so I guess I’m hoping he head isn’t cracked or bad gaskets. I have nothing leaking.

I can drive with 0 issues on a hot day with ac, it is traffic that is the killer. I am going to check if I have a bad head gasket tomorrow, how do I check for a cracked head without tearing it apart?

Head gaskets are often put in backwards. Probably because the assembler thinks both sides should have the gasket "pretty side up."
It happens. Nothing to be embarrassed about. I've been guilty of putting the thermostat in backwards myself.

The thing is, I can't remember a single case of factory components, in good repair, causing an overheating problem. Trouble shooting should always be first rather than throwing money at wonder drugs or parts.

 

[Broncobowsher]

If you can drive freeway speeds with the A/C on and not get hot you don't have any major issues. Nothing cracked, no bad gaskets.

As stated, you have an (idle) airflow issue.

 

[Joe473]

If you can drive freeway speeds with the A/C on and not get hot you don't have any major issues. Nothing cracked, no bad gaskets.

As stated, you have an (idle) airflow issue.

I have heard about different sized crank and water PMP pulleys mixed up to cause low fan speed and water pump speed at idle. Is is possible crank pulley is small version and water pump is large version. Maybe swapping pulleys to get a little more fan speed with a clutch fan to reduce drag at high rpm

Sent from my SM-G900V using Tapatalk

 

[bronconut73]

BC has the biggest crank pulley and smallest water pump pulley you can fit on an eb.

I would still suggest the Explorer serp swap.

 

[blubuckaroo]

mduenas, is yours an automatic tranny?
The idle speed on those is critical.

 

[nvrstuk]

Fix the fan and shroud issue...low rpm cooling issue like a dozen have already stated is airfloww-agreed.

IF the fan, shroud, radiator spaci g and clearances arent right, the fan cant compensate for that at low rpm idle speeds.

 

[DirtDonk]

...Next, I used a radiator cap tester to test the radiator cap I had just put on, bought from wild horses with a diode in it about 1 month ago, and it failed the test.

Well bummer. Sorry about that. When you have some time to deal with it, give us a call and we'll take it back and refund the money.
You may already have known that, or done it, but wanted to make sure you didn't think you were stuck with a defective part.

...I had a very hard time reading the degrees with it, but it seemed to be at 11 degrees, I advanced it ever so slightly both ways, but ultimately put it back to its original spot as it seemed to run the best from what I could hear and feel, although I am no expert.

Just what was it doing that made you think that a tiny amount one way or the other was not as good? Without driving it at least for a little time you really don't know 100% I don't believe.
While 11° seems to be right in the normal sweet spot, that's "assuming" that your timing marks are accurate. Which is not always the case with Ford engines in our family.
Shame really, that this even has to be something to worry about. But it is.

I still think you should advance it a few degrees even though it seems to be ok now. Just to rule out the possibility. If it really wasn't working well at the advanced settings, then there's nothing you can do but go back.
But I'm still not sure what you were feeling, when just going a couple of degrees advanced or retarded made you think it wasn't running as good.
Frankly, you shouldn't even be able to tell the difference at idle, and even when driving it's tough to make a decision anywhere between 4 degrees and 14 degrees. Other than the throttle response usually seems crisper at the higher advance numbers.

Back to the cap for a moment, this could have been at lest part of your issue. Not that running more pressure keeps an engine cooler in theory, but in reality it can in some cases.
The pressure does not change the thermal transfer ability of the radiator, or the flow capacity of the pump, or anything normal like that. It officially only changes the boiling point of the coolant. So in theory you only avoided boiling out above 220 degrees.
But in reality the pressurization of the coolant can increase the efficiency of the thermal conductivity of the coolant INSIDE the engine block itself. By keeping coolant flowing up against ALL the cast surfaces, rather than just blowing by some of the hotter ones where the heat itself can create very localized steam pockets. Causing an engine to run hot.

When everything is working properly and you don't have hot spots, you can run your engine all day long without a radiator cap installed and it won't overheat. But when something is borderline, you could go over that line with a bad cap.
Now that you have a known good cap, and whether you're still dealing with the overheating or not, then you should be able to determine if pressurizing the system has any part in it by leaving the cap installed for some tests, and then half-turned for other testing.
If there is any change in circumstances and how the temperature gauge indicates, then at least you have one more bit of data that might help determine what's going on.
If nothing changes with, or without the cap, no harm trying. And very little time spent experimenting.

But if you wouldn't mind, please describe what you were experiencing when changing the timing.

Thanks

Paul