still overheating

[Willynch]

1930 Tudor. I have replaced the radiator, had the carburetor overhauled. I have timed the engine, replaced spark plugs. I have power, speed and some pick up, even up hills.

Still over heating after about 30 minutes.

Not sure where to go from here.

I am wondering water pump or head.

I live in southeast michigan. Because of my job, I have not been able to make any of the local Modal clubs; figured that would be a good place for help.

Would appreciate guidance or suggestions. Thanks

[rscardina]

Have you checked the water temp or is it steaming out of the cap? Mine was running water out of the overflow but didn't appear to be overheating. I installed a thermostat and it appears to have resolved my issue. I haven't taken any long trips yet to test it though.

[FRANK PKNY]

If it's overfilled it will spew out coolant from around the cap and out the overflow. Are you sure it's boiling over (steam) the addition of a thermostat in the upper hose works very well for overflow problems. If it's steam you may have a deeper problem IE head gasket , perhaps a test for exhaust gas in the radiator should be done next, not an expensive kit from NAPA. Handy to help diagnose this type of problem.

[BILL WILLIAMSON]

Re-Torque the head bolts & add a jar of old fashioned Bars-Leaks & see I it helps. OH, drop a roofing nail in the top of the overflow, to prevent water "splash" over.
Bill W.

[WestCoast]

I would have the out side of the radiator scanned with an infra red heat gun, that's the positive way to tell what your radiator is doing, if rad is hot at the top and cool or cold at the bottom rad is restricted, hot all over engine problem, cracked head, block, slow timing, poor water circulation from bad water pump, or plugged water passages in the block, check compression to see if you have a leaking head gasket, and do check the rad with an infra red heat gun

[Mitch//pa]

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what did you use for a replacement radiator?

[Willynch]

Replacement radiator was a Brassworks; 6 fins per inch.

WHen it over heats I have been measuring temperature in the top tank with a meat thermometer; typically temp has been low 200's.

When idling, the temp is usually 195-ish.

Seems to me, 1895 when idling leaves little room for heat transfer when driving . Granted, the moving car will have air flow across the radiator.

There is always a little overflow as it heats up. I assumed that was the coolant (water) expanding as it warms and overflowing.

After driving for a while (10 minutes) the radiator seems the "belch" some coolant out of the radiator cap. Temperature drops for a while but then climbs again. When driving, I am relying on the Moto-Meter.

When I finish the drive, I have to refill the radiator requiring almost half a gallon every time. I cannot find a system leak so I am assuming the coolant is boiling away. Maybe that is a bad assumption but the water is going somewhere.

Thanks. Will keep plugging away. Using infra red to measure temp across radiator might be useful.

[burner31]

I have to agree with the others, thermostat.
It helps maintain the negative pressure in the block and regulate the flow into the rad, both will help with cooling/overflow problems.
Worked wonders on mine.

[1crosscut]

Refilling with a half gallon each time is not normal by any means. It makes me think that you may be keeping the radiator too full. As long at the tubes at the top of the radiator are covered you have enough water. Before refilling check to see if the tubes are covered. If so do not add any more water.
Very common for folks to keep adding too much water and feeling that it is over heating because it is puking out the extra water.
Let it find the level of water it is comfortable with.

You should not have any water coming out around the radiator cap. Tighten it down and/or replace the gasket. All your extra water should exit through the overflow tube.

[BILL WILLIAMSON]

DON'T forget the NAIL, it REALLY helps prevent water loss!!!! OH! I discovered that at a CONSTANT road speed, if your temp cycles UP & DOWN at regular intervals, "maybe" every 1 1/2 minutes, it's a SURE thing that you are LOW on water!
Bill W.

[Mike V. Florida]

Originally Posted by Willynch

When I finish the drive, I have to refill the radiator requiring almost half a gallon every time. I cannot find a system leak so I am assuming the coolant is boiling away. Maybe that is a bad assumption but the water is going somewhere.

That might just be the "normal" level for your radiator if you are adding the same amount each and every time.

Take it for a drive, leave it alone when you go back home and then on the second trip see if it needs more that the 1/2 gallon. The water is going out the overflow while you drive.

A couple of things can be done to reduce the water loss. Trimming the fins of the water pump or even drilling holes in the fins I have read works. The thermostat will slow the water from shooting into the neck and out the overflow.

Also remember that the radiator will only work if the water is getting though the block unimpeded, is the block passages clogged with rust?

[Dollar Bill]

When idling, the temp is usually 195-ish.

Does it reach 195 just by start/idling in your garage?

Do you have a thermostat in it? If so, what temperature?

[Jacksonlll]

Sounds to me like you have a pretty good head gasket leak into your water jacket. Combustion gasses getting in to the water. Any water in your oil? Level going up? Next time it is hot, lug it in third and see if it gets worse.

[BILL WILLIAMSON]

I know some don't like to add stuff, BUT a simple overflow bottle, hosed to the bottom of the OVERFLOW tube, & a very leakproof cap, WILL eliminate a lot of problems. When it's shut down & cools off, it WILL SUCK the coolant back into the RADUMATOR!
Bill W.

[nick c]

It could be a blown head gasket, sometimes it will not have water in the oil. It only pushes hot air into the water jacket under compression, on the intake stroke the leak is so small that it blows the small amount of water out the exhaust. Do a compression check and see if you have a cylinder that is lower than the others and look at that spark plug, it will look different than the others.
carry on nick c

[Mitch//pa]

you have not mentioned how high the coolant level is filled in the tank when cold before start up. as "1 crosscut" mentioned in his post
this is very important on the proper filiing on the model A cooling system

[Tom Wesenberg]

I would go to Menards and buy a 10 foot roll of clear plastic tubing that fits the overflow pipe. Then run the tubing into the passenger side and have it fit through a hole in the cap of an empty gallon milk jug. Run the hose to the bottom of the jug, then drive the car and see exactly when the coolant leaves the radiator and how much leaves. Drive the car up a couple hills and see if that makes the coolant leave the radiator. When the test is done you'll have the coolant to dump back in, that is unless it was being overfilled to start with.

[Ron Lachniet]

What you are adding in water is not from over filling. That would find it's own level just over the fins and stop. Don't settle for a bandaid fix. I had my radiator re-cored last winter and we drove from Michigan to the east coast and back through West Virginia on roads with 11% grades for up to three miles with 95 degree temperatures and after 2,500 miles I still do not have to add any coolant. I do have a 165 degree thermostat.

[Jacksonlll]

I sure hope you did not plug up your new radiator with crud from your engine. We are all assuming that the new rad. is good!!!!

[Mitch//pa]

Originally Posted by Jacksonlll

I sure hope you did not plug up your new radiator with crud from your engine. We are all assuming that the new rad. is good!!!!

yep i preach that all the time