Overheating problems - your suggestions?

Ksm · Apr 18, 2017

DirtDonk said:
Is it a 351 or 302?
What else has been done to the engine that you know of? Since it's been doing it all along (or is that just since the A/C install?) do you know the history of the engine?
Have you tuned it since you bought it?

I know you've been here awhile now, but I don't remember everything about your Bronco.
And if you have not experimented with tuning yet, I would do that asap.

Paul

New crate 302 engine was put in several years ago. It was fine until the A/C was put in at a later time. I'm not sure if it's been tuned since the engine was installed but that's something I'll add to the list.

phred · Apr 18, 2017

I've not had good luck with high flow pumps. They move the water/coolant through the radiator and block so fast that it is unable to absorb and expel the heat. My gut feel is you need more airflow. An air dam on top of the core support and blocking any holes in the core support that you can. This will force all the air through the radiator and keep the fan from pulling hot air back over or through the core support.

Sent from my iPhone using Tapatalk

Ksm · Apr 18, 2017

Oh and I'm not sure if this is helpful but my Bronco loves the highway. If I start overheating I just find an open road and take off. It takes a bit but will cool down. My problems are at slower speeds and idling.

Last summer I could spike my temperature just by running through the drive-through to get a drink. In that short of an amount of time. I get back out on the road and the temp goes down drastically.

And to reiterate, all this overheating is when the a/c is OFF. I know I can only use it when I'm driving fast. I've gotten into the habit of turning it off at every stoplight, idle, traffic, etc. I rarely use it.

Bronco Biff · Apr 18, 2017

So this to me seems to show that airflow is the issue .......

Ksm · Apr 18, 2017

Bronco Biff said:
So this to me seems to show that airflow is the issue .......

What should I focus on first then? Replacing the fan to the factory 7 blade?
I've gotten a lot of great suggestions. Just trying to figure out now what order to do everything in...

bteutsch · Apr 18, 2017

Ksm said:
What should I focus on first then? Replacing the fan to the factory 7 blade?

I've gotten a lot of great suggestions. Just trying to figure out now what order to do everything in...

I would start with the 195 degree thermostat. And then fan. Then possibly try a new water pump if the first two don't solve your problem. I would do one thing at a time and test drive it. When you do the thermostat you could also flush and refill the radiator with new coolant.

Sent from my iPhone using Tapatalk

Ksm · Apr 18, 2017

bteutsch said:
I would start with the 195 degree thermostat. And then fan. Then possibly try a new water pump if the first two don't solve your problem. I would do one thing at a time and test drive it. When you do the thermostat you could also flush and refill the radiator with new coolant.

Sent from my iPhone using Tapatalk

......says the man who helped dragged my overheating Bronco off a mountain I Arkansas!

okie4570 · Apr 18, 2017

Like mentioned earlier, start simple first imo. Tuning, timing. Then move to the "parts swap" stage. I'm not sure why air flow would now be an issue because you added a/c, especially when the unit is not in use even.

bteutsch · Apr 18, 2017

Yep I can verify it overheats, it is definitely not a gauge problem.

Sent from my iPhone using Tapatalk

okie4570 · Apr 18, 2017

Ksm said:
......says the man who helped dragged my overheating Bronco off a mountain I Arkansas!

Forgot about that, you shiny painted bronco members stick together at OCBR lol

Slowleak · Apr 18, 2017

okie4570 said:
Like mentioned earlier, start simple first imo. Tuning, timing. Then move to the "parts swap" stage. I'm not sure why air flow would now be an issue because you added a/c, especially when the unit is not in use even.

The condenser is blocking, or rerouting airflow to the radiator. It sounds like the shroud and fan may have been changed at the same time the a/c was added.

crankman · Apr 18, 2017

Ksm said:
What should I focus on first then? Replacing the fan to the factory 7 blade?
I've gotten a lot of great suggestions. Just trying to figure out now what order to do everything in...

Does sound like airflow how far in is your fan in the shroud? Does it have a fan shroud? Try this cheap test while engine running take a t shirt and toss it up flat against the front of your grill. If you have good airflow at idle it should suck that t shirt up and it will hold tight there on its own. Take a picture of your fan as suggested lets see how far in it sets.

okie4570 · Apr 18, 2017

Slowleak said:
The condenser is blocking, or rerouting airflow to the radiator. It sounds like the shroud and fan may have been changed at the same time the a/c was added.

This is why they pay you the big bucks

I'm learning something everyday!

73azbronco · Apr 18, 2017

If it overheats even with AC off its an obvious airlfow issue, all things equal. But start with a good tuneup, check timing, etc. Then think about the airflow issue.

Ksm · Apr 18, 2017

okie4570 said:
Forgot about that, you shiny painted bronco members stick together at OCBR lol

We can't help the fact our Broncos are how should we say more good-looking that your average crawler? Hahahahaa;D

okie4570 · Apr 18, 2017

Ksm said:
We can't help the fact our Broncos are how should we say more good-looking that your average crawler? Hahahahaa;D

Ouch...... but true ;D

Ksm · Apr 18, 2017

okie4570 said:
Ouch...... but true ;D

Your half-cab can join the club.

okie4570 · Apr 18, 2017

Ksm said:
Your half-cab can join the club.

I probably won't ever bring it back to OCBR.

bteutsch · Apr 18, 2017

Was yours the one that got rocks slung all over it?

Sent from my iPhone using Tapatalk

blubuckaroo · Apr 18, 2017

Ksm said:
I've been battling an overheating problem ever since I added the Vintage Air system. It overheats while idling at stoplights, traffic, etc. all with the a/c off.
I'm going to list out everything I have or have tried and hopefully y'all can give me some suggestion on what to try next????

Gen IV Vintage Air
Triple core radiator
16 lb radiator cap
shroud
pump pulley
6 blade fan (not a reverse fan)
High Volume water pump
180 thermostat

Any ideas on what I can try next? I'm thinking about switching to a 70/30 coolant mix. We're in Texas so it never gets cold anyway. Maybe switch to a seven blade fan? Switch to a 195 thermostat (even though that seems counter-intuitive). A clutch?
A wizard?

I see you've listed a "pump pulley" on your list of fix attempts. Can you explain what you did and why?
Also, is there a chance you've put the thermostat in backwards?

Overheating problems - your suggestions?

Bronco Guru

Bronco Guru

Bronco Guru

Sr. Member

Bronco Guru

Sr. Member

Bronco Guru

Bronco Guru

Sr. Member

Bronco Guru

Bronco Guru

Sr. Member

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Sr. Member

Grease Monkey

Similar threads