Radiator steams after short drive.

JimG1127

JimG1127

Member
I'm the proud owner of a '29 roadster for all of 2 weeks! Much to learn! Under the hood looks very stock. A week ago I opened the Flying Quail radiator cap to check the coolant level. I could see a metal plate a few inches down. No coolant covering it. So I added some Prestone. Went for a drive of maybe a mile and a half. Parked it in my driveway and turned off the engine. Quite a bit of coolant came out the overflow tube. Quite hot. I have not added any more coolant since. Went for a drive today of maybe 2 miles. Parked the car and turned off the motor. Lots of steam coming out of the overflow tube.
- Is the Model A radiator pressurized?
- Is this normal? I've read here a Model A radiator will find the level it likes.
- Is the Quail radiator cap doing its job? I don't see a gasket on it.
I'm afraid right now of driving it and possibly overheating it.

I've been looking at Mikes Affordable and I like the idea of the oil filter kit. Anyone familiar with it? Is it good?
The gas line coming out of the firewall goes through a brass bulb looking thing. Is that a filter?
- Tips on winterizing? I have filled the gas tank and added stabilizer.
Thank you all for any much needed advice!
- Jim
 
Excess coolant will be expelled but steam is not normal. Several things can cause the car to run hot:

The radiator and engine need to be flushed. Some detergent will get rid of any grease scum and vinegar will help clean out the rust.

The radiator needs to be replaced.

The ignition is not set correctly.

The fuel/air ratio is not correct.

The radiator cap should have a gasket but not having one will not make the car run hot. Your radiator is open to atmospheric pressure, not pressurized.

I have the glass bulb on my car but I think the brass one is also a sediment trap like the glass one. Heavy particles will settle out of the gasoline and fall to the bottom of the trap. It should also have a screen at the top to further filter out stuff.
 
nkaminar said:
Excess coolant will be expelled but steam is not normal. Several things can cause the car to run hot:

The radiator and engine need to be flushed. Some detergent will get rid of any grease scum and vinegar will help clean out the rust.

The radiator needs to be replaced.

The ignition is not set correctly.

The fuel/air ratio is not correct.

The radiator cap should have a gasket but not having one will not make the car run hot. Your radiator is open to atmospheric pressure, not pressurized.
Click to expand...

Or a blown/leaking head basket. https://youtu.be/5ae4NDjHr4Y
 
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Thanks for the good info. I think I will flush out the system today and let it sit overnight with vinegar. A good cleaning should help.
Funny how when I test drove it before buying it this problem did not appear.
- Jim
 
There can be an internal leak in the head gasket that would not be seen on the outside. There can also be a crack. The test is to take your fan belt off and fill the radiator to the top. Run the engine and see if there are any bubbles coming up to the top of the coolant. Also see if there is steam out the exhaust pipe or water in the oil.

Your plan to flush the radiator is a good one.
 
How are you adjusting the timing, the lever on the left side of the steering wheel? Up to start then down a couple clicks for warning up, down about halfway for normal driving, all the way down for highway driving, move the lever up a few clicks if you hear or feel knocking
 
All the suggestions about timing, head gasket, cracks etc. are valid. But 9 times out of 10 it is a clogged radiator that causes overheating. Pull the radiator and bring it to a radiator shop to be rodded out.
 
Make absolutely sure that you are advancing the AFTER she starts. Many new owners don't know that this is model A timing and should be set with the RPM and the ear If not, she will over heat . Next Don't over fill. Fill up to the bass plate and no more. Is the car losing coolant? Take it out for a few more runs and see how much it's down (Below the plate) Check your exhaust for a lot of condensate (white steam) after it's hot. Try to figure out exactly what's going on before you start wrenching. It may be nothing or it may be serious.
Terry
 
Big hammer said:
How are you adjusting the timing, the lever on the left side of the steering wheel? Up to start then down a couple clicks for warning up, down about halfway for normal driving, all the way down for highway driving, move the lever up a few clicks if you hear or feel knocking
Click to expand...


Also - don't run with the fuel mixture too lean (learned that one the hard way!); for my Model, about a 1/4 turn open is just about right most of the time.
 
Mikes filter kits are great, I have a few of them.

If you fill the radiator to the top it is very common for the car to expel it out the overflow tube. Let it burp it out and leave it alone. Don't keep filling it.

Many times a head gasket will slowly let go just enough internally suck out some water as you are driving and you will not see and drips in the engine bay. i am not saying you have a bad gasket, I am just saying.

Winterizing, get yourself a cheap antifreeze tester Wallmart, Amazon, NAPA etc. If you use the concentrate you will be able to get the antifreeze to a good for -40 below. The 50/50 mix will not go that low.
 
Yes, i move the spark lever all the way up to start and then move down when running.
I think I found the problem. It had been masked by all of the steam coming out of the overflow tube. Today I filled the radiator all the way up with water. started the car and opened the hood and looked all around while it idled. What do you know, coolant seeping out of the water hose where it goes into the block. Wow! That simple. I tightened the clamp quite a bit. All of the clamps needed and got tightened. I let it run for a while and it looks like that was it. I'm going to replace the hoses and clamps because they look old. Appreciate the tips.
Would like to hear what you do to winterize your A.
Thanks.
 
For not a ton of money you can add a temp gauge to really see what the coolant temp is doing. I always thought my radiator was marginal. Added a temp gauge and found it runs in the 140-150 range. You might not have much of a problem other than overfilling.
 
So I put on new hoses, clamps, water pipe. New graphite packing on the water pump. Flushed water through system., Drained. Filled it with white vinegar and drove it around. Let it sit overnight. Drained it. Very rusty looking water. Filled with water. drove it around. Let it cool. Drained it. Did this flush process with water about 8 times. Water now comes out pretty clean.
After driving car while its idling I check it with an Infrared Thermometer. Upper radiator about 200 degress. Radiator gets cooler as I move down. When I turn off the engine the temp goes up.
Tried the water test. Took off the bottom hose. Stuffed a rag in the lower radiator opening. Filled the radiator with water. Pulled rag out. Water was coming out at a decent volume for about 8 seconds. From what I've read this is not good. Radiator has white stains on front but doesn't leak. Do I need a new radiator?
 
Take the radiator out and do your flow test with the radiator upside down. Taping the inlet closed and use a ball in place of the cap, do it until rust flakes stop coming out.
 
JimG1127@Gmail.com said:
After driving car while its idling I check it with an Infrared Thermometer. Upper radiator about 200 degress. Radiator gets cooler as I move down. When I turn off the engine the temp goes up.
Tried the water test. Took off the bottom hose. Stuffed a rag in the lower radiator opening. Filled the radiator with water. Pulled rag out. Water was coming out at a decent volume for about 8 seconds. From what I've read this is not good. Radiator has white stains on front but doesn't leak. Do I need a new radiator?
Click to expand...

200° is pretty warm. How warm is the water coming out of the bottom of the radiator? You may have to have your radiator rodded out. Hard to diagnose not knowing much about your engine and how it is timed. Retarded timing will make it run hot.

The temp rising after you shut it off is normal, heat soak. Any engine will get warmer when shut off. Take that off your worry list.
 
Anti-freeze chart, courtesy of Detroit Diesel.
 

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