BeansWorld

Team,

My most recent changes were removal of the filler cap and installation of a block plate at the water filler neck (filler cap was actually just hitting the underside of the hood and had vibrated loose a few times, spewing antifreeze everywhere), with Milodon 180 degree hi-flow thermostat. I pulled a 195 degree thermostat out installed by the PO. I bled the system and refilled as necessary, running on ramps to elevate the radiator without the radiator cap until it got up to operating temperature. Electric fans engage. Thermostat opens, flows through the Be Cool radiator. Temp stays low and hot air running from the vents at all times. I put the radiator cap back on and the temp will start to climb.



Temp sensor for electric fans at intake manifold. Temp sensor for gauge installed in rear of water filler neck.

Should I be concerned about the location of the temperature sensor in the water filler housing? Heads are aftermarket so that limits OEM install location. Should I have used a plate with a bleeder valve? I should have enough clearance to do that.

Water pump is about 6 months old Edelbrock Victor series, hoses are new, heater core replaced by Vintage Air system. This is starting to drive me crazy.

Yesterday I drove for a good 30 minutes then pulled over for some pictures. I noticed the electric fans never came on during the drive, it was about 60 degrees and I was just cruising. These are supposed to come on around 185 degrees I believe. I didn't think much of it. I let the car idle during the second set of pictures and saw the temp gauge go over 210 in just three minutes. Shut it down, let it sit for a while with the electric fans on and after 15 minutes, started and it ran cool for the 30 minute drive home. I could sure use some help.

Anyway, here's a few pictures that made the day a winner.

Alan 71

Hi BW,
Remember when the car is sitting the cooling system gets it's air supply through the cut-outs in the lower valance.
Do you have the lower flap-seal between the valance and bottom of the core support and also the seals on the 4 sides of the radiator?
These are intended to FORCE the fan(s) to pull that fresh air through the radiator, not around it.
Maybe?
Regards,
Alan

This is the left side of the flap, it extends all the way across to the right-side apron.

1974ta

If you have a copy of your AIM, check out the seals in and around the radiator as well as the hood to radiator support. All the seals are as Alan says, to force the air through the radiator.

There was also a very recent post where too much RTV was used to seal up the intake and some of the water passages were blocked. While running take off the radiator cap and look in the radiator. When the thermostat opens, you should see the water flowing freely.

Love the 17" Cragar SS wheels. Did you have to do any mods to get them to fit?

Beautiful Ride.


Bill

Mike Ward

You have a problem with the fans.

C3Hawk

That's what I'm wondering. So if I understand you right, the fans never came on while the car was sitting there idling during the first and second picture session?

Mike Ward

I don't know of they did or not but since you only have a problem with extended idling, it doesn't sound like rad, pump or seals.

C3Hawk

It's not my car Mike, I was asking the OP if the fans came on or not!
I also agree the owner should look at the fan circuit.

BeansWorld

Alan71, I know the seals above the radiator are in place that push up against the hood. I'll check for those connecting to the sides etc.

Bill, thanks for the compliment! Suspension is full VBP with offset trailing arms in the rear. Rear tires are 275/40R17.

Problem with the fans seems likely. I need to verify if they turn on properly at 180 degrees, the fan light I have set on my gauge cluster definitely did not light while I was cruising to the photo location but I didn't think much of it at the time. I installed a trinary switch with the Vintage AC unit and just had the AC evacuated and charged earlier in the week. This was the first cruise with the AC operational. I need to verify the wiring to the fan relay and pay attention to when the fans actually engage. This seems to be a likely culprit since I didn't suffer from these symptoms prior to this week. Of course it was other problems beforehand!

Thanks team, I'll keep you posted.

-Eugene

doorgunner

AAAAAAAHAAA!

Vintage Air.......my '34 street truck NEVER overheated until I installed the V.A. unit.

I had to add a pair of low profile pusher fans to the front of the radiator----they were then wired into the compressor wiring using relays so that they would turn on with the compressor, which kept the condenser and radiator from overheating.

That solved my V.A. overheating problem.

BeansWorld

It's raining so I haven't had a chance to take a test run. But I've been thinking about this...

I ran the car nearly 1000 miles this summer without these symptoms. The Vintage AC system was installed but never evacuated and charged. So I never engaged the AC.

The electric fans always engaged properly prior to activating the AC system. Maybe the fans engage properly only when the AC was on? I rode home from the shop with the AC engaged, even though it was cold that day You would've done the same!

So that should rule out any issues when I tapped into the wiring from the electric fan relay to the temperature sensor. The rest of the trinary switch is simple: ground, compressor and wiring harness to condenser.

I suppose it could be coincidence that the AC was charged prior to this issue. Electric fan relay or temp sensor a possibility? I reached out to Be Cool for waring harness information and troubleshooting assistance.

Thanks again for the help, I think I'm moving towards a fix.

doorgunner

It took me a while to understand/verify what was happening with the overheating.....I verified it was A/C related immediately......then it took a while to understand how the electric fans needed to be wired.

You probably already know that the a/c condenser gets as hot or hotter than the coolant entering the radiator when the A/C is on....the radiator is dealing with double the heat and with less air-flow because of the condenser in front of the radiator.

Keep us updated (you might discover a better way to synchronize the fans than what I have now!)

BeansWorld

Doorgunner,

Oddly enough, the AC was not on when the car overheated at idle; since the fans were not engaged I assumed faulty wiring to the trinary switch. That may not be the case, so I'll need to test varying scenarios...

I had proper cooling all summer with the condenser in front of the radiator all summer though the AC was never engaged. Cooling was not an issue when I drove home with the AC engaged, though I had very little idle time.

I should know more once I test the failure scenarios, I'll be sure to post.

Thanks,

Eugene

doorgunner

I drove with my V.A. Uncharged during the summer also......the 2,200 c.f.m. Electric puller fan kept the engine at 180*. Heating problems didn,t start until I had it charged and began using it the next summer in temperatures above 90*.

Thanks for keeping us updated.

BeansWorld

We had a nice weekend here in Northern VA (about 60 degrees), so I ran another test. I let it warm up to around 180 degrees, the IR thermometer verified 170 degrees at the temperature sensor mounted in the rear of the thermostat housing and at the intake manifold where the temperature sensor for the electric fans is mounted. The electric fans engaged and the thermostat opened; the temp of the upper radiator hose increased around 20 degrees. It ran like this for a few minutes, then the electric fans disengaged, temp crawled up a bit and fans engaged then stayed on for the duration.

Here's the gauge reading when I verify around 170 degrees at the thermostat housing:



Here's the gauge reading after driving for a minute:



I had the heat engaged (blew hot), then engaged AC but saw no difference in operating temperature. Both temperature sensors measured around 200 degrees. Electric fans were operating as expected. I would've driven it beyond the immediate neighborhood but I'm having another issue and will start a new thread...

Be Cool recommended a 160 degree thermostat to allow the electric fans to disengage, claiming the sending unit activates the fans at 195 and turns them off at 175. I didn't experience these values when testing with the IR thermometer. I'm thinking more like 185/165 or maybe 180/160. Before replacing the thermostat, my electric fans never disengaged after reaching operating temperature.

I recently replaced the thermostat from a 195 to a 180 degree hi-flow Milodon unit. I also removed the cap at the thermostat housing to a blank plate to address hood clearance. I could potentially use a plate with a bleeder valve. The Vintage AC unit was recently charged and used for the first time, though I finished the installation in March. These are my only recent changes to the cooling system.

My last thought - should I keep a 195 degree thermostat considering the engine would be built for optimum performance at a specific operating temperature? I can't verify this but the PO had the 195 degree thermostat installed and the engine built at a local speed shop. Temperature gauge always read just a tick above the reading in the first picture when the 195 degree thermostat and cap at the thermostat housing / water filler neck was installed.

Any thoughts?