Running hot, where do I start the fix?

[47topless]

My stock '47 V8 Runs way too hot, even for a FH. By the time I get back from the grocery store, the heat gauge needle is buried. Getting back home, there is no angry steam spewing from the radiator and just a small amount of water dripping from the overflow. There appears to be some water weeping from the pumps, especially the right one.
Now where shall I begin to fix this problem?
1. Can I flush the radiator without removing, perhaps just remove the lower hoses? 2. Will I kill the engine if I run a flushing agent through it? What flushing agent is best? 3. Should I just get a couple of Haney pumps and replace the old ones? 4. Does anyone produce a radiator (fan) shroud for these cars?
5. Should I just give it up and buy a Prius?
Thank you,
Phil

[SoCalCoupe]

I'd start with verifying your temperature indication. If the temperature indicator is off you'll be chasing your tail. A decent infrared temp gun can be had for $25.

[mfirth]

Prius ?????? N E V E R !!!! Times 2 on what SoCalCoupe said. Slow down, be patient. I have an after market temp gauge for each head mounted under the dash. Much more accurate. New hoses & thermostats MIGHT be a place to start. Determine if you have a leaking pump & address that. It can be fixed, hang in there. Skip rebuilds them ......

[Floyd]

Relax, your car is not running too hot. Even Henry Ford himself said and printed it in the owners manual that if the car is NOT steaming, then it is not too hot.
Next item is nothing is more accurate and reliable then the Ford installed King Seeley temp gage and sender if it is properly wired and functioning. Aftermarket stuff is junk.
A leaking water pump is just that , a leaker but has nothing to do with "overheating"
The fact that the gage is "buried" after the trip means that the sender is bad and has lost its connection to the gage or
2 the wiring has opened up somewhere in the connection
3 you have low water and there is none in the head to measure.
A proper operating gage and sender will "bury " itself to the right side only if there is no power to the circuit just like when the ignition is "off".
If you were in an overheating situation and you were at boiling temperature of 212 F the gage would not be "buried" but would be at the "H" line and no higher.
Cleaning and flushing the cooling system is always a good idea and replacing a leaky pump (do both while at it) is also wise.
As mentioned, get an infrared heat gun at Harbor Freight or somewhere and use it to measure the water temp in the top tank with the cap off. You have a temp sensing problem first.

[drolston]

First, some questions: Did this problem come on suddenly, or creep up on you? Have you recently made any changes to the car? Carb, ignition, brakes, coolant, head gasket, etc.?

The steaming you report is the definition of too hot for a flathead. Where to start. First get the IR temp gun. Cheap.
- First basic: Be sure there is enough water in the radiator to cover the tubes by about half an inch to an inch. Be sure the coolant mix is not greater than 50/50. The higher the percentage of water, the better it will cool.
- Second basic: Check rubber hoses for collapsed or kinked; especially the bottom ones.
- Third basic: Be sure the radiator is not plugged with debris or have a lot of folded over fins.
- If all of that is good the first thing to check is for a stuck thermostat. Start it cold, let it idle, and check temp with the gun at the water outlet at the top of the cylinder heads on both sides. When the temp at those spots hits 160, start checking for the flow to be visible through the radiator cap. You should see brisk flow by the time the temp at the head outlets gets to 180. You should also see the temperature at the top input to the radiator start to come up to about that of the temp at the head outlet. If both sides show the temp equalize between the head and radiator inlet at something between 160 and 180 (depending on which thermostats), the thermostats are not the problem.

If the problem is not revealed by these tests, check back for advice on next steps.

[SoCalCoupe]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Floyd

nothing is more accurate and reliable then the Ford installed King Seeley temp gage and sender if it is properly wired and functioning. Aftermarket stuff is junk.

As mentioned, get an infrared heat gun at Harbor Freight or somewhere and use it to measure the water temp in the top tank with the cap off. You have a temp sensing problem first.

What Floyd said.


I had the same symptoms, bought the temperature gun, followed Floyd's steps to see what was really going on.


Can't guarantee what you'll find, but in my case, matching the indication on the 75 year old dashboard to the reality of a 21st century temperature gun was the answer to the problem.


Good luck!


Keep writing to tell us how you're progressing.

[47topless]

Great advise. I'm off to the local Harbor Fright store on Tuesday.
Thank you!!

[47topless]

Originally Posted by Floyd

Relax, your car is not running too hot. Even Henry Ford himself said and printed it in the owners manual that if the car is NOT steaming, then it is not too hot.
Next item is nothing is more accurate and reliable then the Ford installed King Seeley temp gage and sender if it is properly wired and functioning. Aftermarket stuff is junk.
A leaking water pump is just that , a leaker but has nothing to do with "overheating"
The fact that the gage is "buried" after the trip means that the sender is bad and has lost its connection to the gage or
2 the wiring has opened up somewhere in the connection
3 you have low water and there is none in the head to measure.
A proper operating gage and sender will "bury " itself to the right side only if there is no power to the circuit just like when the ignition is "off".
If you were in an overheating situation and you were at boiling temperature of 212 F the gage would not be "buried" but would be at the "H" line and no higher.
Cleaning and flushing the cooling system is always a good idea and replacing a leaky pump (do both while at it) is also wise.
As mentioned, get an infrared heat gun at Harbor Freight or somewhere and use it to measure the water temp in the top tank with the cap off. You have a temp sensing problem first.

Wonderful information. I will proceed as directed. LOve that handmade illustration. I will print and post in my garage. Thank you!

[47topless]

Originally Posted by drolston

First, some questions: Did this problem come on suddenly, or creep up on you? Have you recently made any changes to the car? Carb, ignition, brakes, coolant, head gasket, etc.?

The steaming you report is the definition of too hot for a flathead. Where to start. First get the IR temp gun. Cheap.
- First basic: Be sure there is enough water in the radiator to cover the tubes by about half an inch to an inch. Be sure the coolant mix is not greater than 50/50. The higher the percentage of water, the better it will cool.
- Second basic: Check rubber hoses for collapsed or kinked; especially the bottom ones.
- Third basic: Be sure the radiator is not plugged with debris or have a lot of folded over fins.
- If all of that is good the first thing to check is for a stuck thermostat. Start it cold, let it idle, and check temp with the gun at the water outlet at the top of the cylinder heads on both sides. When the temp at those spots hits 160, start checking for the flow to be visible through the radiator cap. You should see brisk flow by the time the temp at the head outlets gets to 180. You should also see the temperature at the top input to the radiator start to come up to about that of the temp at the head outlet. If both sides show the temp equalize between the head and radiator inlet at something between 160 and 180 (depending on which thermostats), the thermostats are not the problem.

If the problem is not revealed by these tests, check back for advice on next steps.

Just bought this car and it was there on my first test drive. Have not made any changes to engine, (yet!). Thank you

[cadillac512]

Before misinformation leads this thread astray, the owner did NOT say he had steam from the radiator. IN fact.... "Getting back home, there is no angry steam spewing from the radiator and just a small amount of water dripping from the overflow."
Carry on....


Terry

[Floyd]

To follow up what "cadillac Terry " just said. He has no steam, therefore my first line was that he does not have an overheating problem. Also from the image of the owners manual, even Henry says he does not have an overheating problem.
one thing that I did not cover but was picked up by "drolston" is to also check for stuck thermostat which will let the temp gage rise due to the blocked water flow, but the gage will not exceed the "H" line.
The temp numbers shown on the "children's art project" drawing are actual water temperatures measured with a thermistor using several genuine King-Seeley senders. No variation was found between the NOS and a vintage in-service senders. A proper operating OEM system in your car is that good! ( 6 Volt, all Henry)

[drolston]

Originally Posted by Floyd

To follow up what "cadillac Terry " just said. He has no steam, therefore my first line was that he does not have an overheating problem. Also from the image of the owners manual, even Henry says he does not have an overheating problem.
one thing that I did not cover but was picked up by "drolston" is to also check for stuck thermostat which will let the temp gage rise due to the blocked water flow, but the gage will not exceed the "H" line.
The temp numbers shown on the "children's art project" drawing are actual water temperatures measured with a thermistor using several genuine King-Seeley senders. No variation was found between the NOS and a vintage in-service senders. A proper operating OEM system in your car is that good! ( 6 Volt, all Henry)

My mistake regarding the steam. I missed the negative. Apologies to all.

[Floyd]

No apology needed here. You are the guy that noted a stuck thermostat could be the problem IF he had an overheating problem. I missed that item in my reply.

He is off to HF to get a temp gun. Hopefully we will have some real data to get him thru this situation.

[Tim Ayers]

The same company that makes No-Rosion sells a really good block/rad cleaner.

https://www.no-rosion.com/norosionflush.htm

Once you get things sorted out, may be a good idea to get things nice and clean so you know that's not a concern going forward.

[47topless]

Bought the infrared gun and made an attempt to do Floyd's test.
Cold start, at idle, no load.
1. Temp at head inlet, 165, no radiator flow
2. Temp at head inlet (both left and right about equal), 170, no radiator flow
Temp gauge now buried to the right.
still no flow seen in radiator cap opening.
3. Left side-head inlet temp at 180 and inlet at radiator temp 173
Right side head inlet temp at 180 and inlet at radiator temp 173.
NO FLOW IN RADIATOR, NO BOILING FLUID IN RADIATOR, GAUGE STILL BURIED TO RIGHT SIDE.

Would these results indicate a thermostat problem?
Do I also have a sending problem?
Thank you
Phil

[cadillac512]

I'm leaning toward a sender/wiring problem. But first, have you checked the temp of the cylinder heads ? That would be very valuable info to have. Right below the necks where the hoses attach would be a good spot to check.



Terry

[marko39]

feel the hoses above the stats, you can tell when they get hot indicating stats opening.

[47topless]

Originally Posted by cadillac512

I'm leaning toward a sender/wiring problem. But first, have you checked the temp of the cylinder heads ? That would be very valuable info to have. Right below the necks where the hoses attach would be a good spot to check.



Terry

Yes, I think I have a sender problem.
I did take the temp just below the hose attachment on the head.
Thanks

[47topless]

Originally Posted by marko39

feel the hoses above the stats, you can tell when they get hot indicating stats opening.

Now that is a commonsense idea. Thank you so much!