Overheating Checklist

Mike1291

Mike1291

Senior Member
Once I get the brakes on my car back together I plan on solving the issue I have with overheating. If I go fast (45 mph) when it's warm out (>75°F) it gets hot fast and starts running poorly after a minute or two. After 5 or 10 minutes I loose most of my power and coolant.

I'd like to get a checklist of things I can go through so I can troubleshoot what's going on. This is what I have so far, and I'd like your opinions/suggestions.
  • Plugged Radiator
  • Cracked head
  • Bad head gasket
  • Carb too lean

I already checked my timing and my coolant is in good shape, so that's covered.
 
Mike1291 said:
Once I get the brakes on my car back together I plan on solving the issue I have with overheating. If I go fast (45 mph) when it's warm out (>75°F) it gets hot fast and starts running poorly after a minute or two. After 5 or 10 minutes I loose most of my power and coolant.

I'd like to get a checklist of things I can go through so I can troubleshoot what's going on. This is what I have so far, and I'd like your opinions/suggestions.
  • Plugged Radiator
  • Cracked head
  • Bad head gasket
  • Carb too lean

I already checked my timing and my coolant is in good shape, so that's covered.
Click to expand...

They tend to get warm if too far retarded...

48914508956_3d7217047e_c.jpg
 
Mike I would suggest getting a dial type meat thermometer to place directly into the coolant while leaving the radiator cap off. You can drive the car with the cap off and the thermometer in place. Doing this will tell you the actual temperature of the coolant is. This will help in the diagnosis. You can use an infrared temperature gun but the dial type works every time and never needs batteries.
Blockhead is correct that running too retarded will cause an engine to overheat.
What steps did you take to set the timing?
 

Attachments

  • 2052.54af6933.jpg
    2052.54af6933.jpg
    5.6 KB · Views: 7
Wow! It's crazy that the A's exhaust could be that red. I timed my car by removing the timing dimple and inserting it in backwards, hand cranked my engine until I felt the dimple exactly on the mark on the timing gear, and set my distributor with a Nu-Rex wrench per it's procedures for TDC. I had my spark lever about two notches down from the top of it's travel. I regularly run with it ¾ or all the way down at speed.
 
Good method on the timing.
Did you check to see that the arm on the distributor was able to move fully in the slot on the distributor body and is able to touch each side of the opening?
I’d suggest setting the timing with the lever all the way up.
Driving with the lever all the way down usually isn’t necessary.
 
Yes, the spark lever has full range of motion and is properly aligned with the distributor body. I set mine to be two notches down in case I ever have to crank start it (all the way up is thus 4 degrees past TDC and thus no chance of kickback).
 
Good starting point knowing that the timing is properly set.

As far as a checklist for going forward:

Torque the head bolts.
Start with the torque wrench set at 35 lbs. Then go up to 45 and then to a final torque at 55lbs. This will give you an idea as to what the torque values were on each one instead of just setting it at 55 right off the bat.

Check the coolant for exhaust gases.
You can get a fairly inexpensive test kit from any of the automotive parts stores that pulls air from the radiator through a solution that will change color if exhaust gases are present. The kits are set up so you hook them to a vacuum line to pull the air through the solution but you can suck the air through by using your mouth sort of like puffing on a cigar without inhaling.
Maybe do this before you torque the head.

Check to see that your radiator fins are not clogged with dirt and grease blocking air flow.

Check to see if the fins are securely attached to the tubes.

Straighten any bent fins using a small flat bladed screw driver.

Clean the radiator.
I have had good success by removing the radiator then blocking the lower outlet and overflow tube and putting in one gallon of straight Simple Green for a few days while inverting the radiator several times each day sloshing it around. This will get the grease and dirt out making it easier to go after rust and lime scale afterwards if necessary.

If you have coolant puking out of the radiator cap you need to get a new gasket for the cap. Coolant shouldn't come out of the cap regardless if it is overheating or not it should come out of the overflow tube.

As I mentioned earlier knowing the actual temperature of the coolant will help.
Many have thought that their engines were overheating when actually it was just that the radiator was overfilled or they had a bad head gasket pushing coolant out when under heavy acceleration.
 
Thanks for all of the tips! I'm nearly on the road and I think the easiest thing to do right now is check for a head gasket leak using the exhaust gas tester. I could also run the car and measure the head using a laser thermometer to see if it's really overheating
 
With the head off,take and stick a magnet in the rear water jacket of the block, use a old broken band saw blade to work loose the crud buildup. This will take a couple of hours to get it all clean.
 
x2 with wick.

It is amazing the amount of crud that will come out of some engine water jackets with a magnet.
 
Also I found if I did not have the advance lever set right my car would overheat. The sweet spot for my '30was about the 9:30 position (A little below level with the horizon. Chap
 
I appreciate the comments. I'm definitely thinking it's head related because even in winter I'll have coolant come out of the overflow, even though the engine is barely warm (~115F). Only way it would come out there is if something pushed it out at that temperature.
 
old31 said:
x2 with wick.

It is amazing the amount of crud that will come out of some engine water jackets with a magnet.
Click to expand...

I use water pump lubricant, or something akin to that in my water every year to keep the rust in check. And when I start draining it in the fall, I pour that water back in the thing, so as not to intruduce fresh oxygenated water into the system
 
Mike1291 said:
I appreciate the comments. I'm definitely thinking it's head related because even in winter I'll have coolant come out of the overflow, even though the engine is barely warm (~115F). Only way it would come out there is if something pushed it out at that temperature.
Click to expand...

How full are you filling the radiator? The coolant will expand quite a lot as it warms up.
Knowing the temperature of the coolant when it is looking like it is overheating is key. Use the probe type thermometer placed directly into the coolant. Best way of determining the actual temperature of the coolant.
 
1crosscut said:
How full are you filling the radiator? The coolant will expand quite a lot as it warms up.
Click to expand...

Only until I can barely see it above the cores

1crosscut said:
Knowing the temperature of the coolant when it is looking like it is overheating is key. Use the probe type thermometer placed directly into the coolant. Best way of determining the actual temperature of the coolant.
Click to expand...

Will do. Planning to drive and test the temperature in the coming days when the weather is nicer.
 
very useful list check list for us all, Ford Barners ... can we add to it ?
Possible causes of overheating
• Cylinder head cracked
• Cylinder head insufficiently torqued
• Head gasket bad
• Fuel mixture too lean
• Water jacket filled with crud
• Ignition too retarded
• Water pump ineffective
• Radiator -plugged internal passages
• Radiator-plugged external fins
 
johnbuckley said:
very useful list check list for us all, Ford Barners ... can we add to it ?
Possible causes of overheating
• Cylinder head cracked
• Cylinder head insufficiently torqued ✓
• Head gasket bad
• Fuel mixture too lean
• Water jacket filled with crud
• Ignition too retarded ✓
• Water pump ineffective ✓
• Radiator -plugged internal passages
• Radiator-plugged external fins✓
Click to expand...

Great list of things. Checked off things I've tried that were OK. I will try the more invasive ones later.
 
Last edited:
You must log in or register to reply here.
Back
Top