39 Buick Overheating, Vapor Lock, 6V eletric fan

[Guest 39BuickSpecial]

A few week ago, my 39 Buick Special heated up waiting for a traffic light change on an interstate exit ramp. I was "keeping pace" with traffic doing a steady 55 to 60 mph. I was monitoring the temp gauge and averaging circa 168 to 170F, outside temperature was around 88F and humid.

No problems at all until waiting on the exit ramp for a green light.

While waiting the temp climbed from 170 to over 200 in less than a minute. Only a few blocks to my garage I proceeded cautiously but traffic kept the speed down to about 25mph. One block from my home I experienced vapor lock.

I've heard about the 39's reputation for over heating. But, this was my first and only time this occured in the three years I've had this car.

Anyone experience similar problems? How did you correct the problem? The Buick tech recommended insulating the fuel line, running a zero pressure radiator cap, and installing a six volt electric fan on the outside of the radiator. Don't know where to buy the fan. Thanks in advance for any suggestions or help.

[Steve_bigD]

Does any coolant get pushed out the overflow when this happens? If so and the temperature climbs that fast when you come to a stop after a high speed run I would suspect the possibility of a head gasket leak which pushes air into the system. Normally the temperature will climb after a high speed run when stopped but much more slowly than you indicated.

I had this happen with my rebuilt 38 special and found it was a small valve seat crack that the shop that did the head for me missed. After getting a new head, re-coring the radiator and using a 7 pound pressure cap my 38 special always runs 170 degrees and even after a high speed run only reaches 190 degrees or so after 15 minutes of idling.

BTW, make sure that you run 50% or less concentration of anti-freeze since it is not as good a transfer of heat as water and higher concentrations will make the engine run hotter.

Vapor lock is hard to avoid with modern gas but assuming the fuel pump is OK and the lines are dressed properly, you could add an electric fuel pump near the fuel tank. I added mine under the right rear door frame rail and added an inline filter between it and the tank. That will cure vapor lock. I used a KEM EFP6 pump with a separate fuse and under dash switch.

Steve D

[trp3141592]

Hi Larry,

I have never had any problem with my '37 Buick Roadmonster overheating. However, I am blessed (?) with two of the most notorious overheating cars ever made--a 1937 Cord and a 1940 LaSalle. Here's what I have learned that works. Use any or all and you'll see improvement.

1. Install a good electric fuel pump as your primary fuel pump. Avoid the AC Autopulse (and other brand clones) click-click-click-click diaphragm pump--I have experienced pinholes in the creases of the bellows, and that means that your car STOPS, always in the worst imaginable time and place. I use a rotary pump, 6 volt, easily available, lifetime warranty. I have a dash shut-off switch for it and I power it with a relay. I run it full time, and I by-passed the mechanical pump.

2. Insulate the fuel line under the hood.

3. Install sheet metal heat shields between the exhaust manifolds and the fuel line.

4. Install a 6 volt radiator fan. This really helps. I installed a dash on/off switch and powered it with a relay. They are available --->> IN SIX VOLTS !!!! <--- at Scotts Cooling Fans, 1-800-272-3267. His web site is not up yet.

I stayed away from a presurized cap--I was concerned about the seals in the water pump and how much pressure they were designed to handle.

Hope this helps.

--Tom

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Edited July 12, 2009 by trp3141592 (see edit history)

[Buicksplus]

Larry:

These are great suggestions. I certainly agree with Tom about the problems with the AC "Autopulse" pump (this inexpensive 6V pump is made under many different names, sold by JC Whitney and others). My 39 Buick vaporlocked badly until I removed this fractious little pump. It did better on the mechanical diaphram pump alone.

My experience with the 6V aux fan is not as favorable. This fan is not very powerful and may actually restrict air flow at high speeds. I had better luck installing an RV flex blade fan right on my waterpump hub. These fans are available at autoparts stores and they move much more air than the original Buick unit.

I might add that if you get the fuel system working right, your Buick can probably run reasonably well (not perfectly) with the engine in the 200 F range. Mine did OK in that range, though it was always hard to start when hot.

It does not hurt to check for exhaust leaks into the cooling system (bad head gasket or head cracks) and flow test the radiator. Any good radiator or repair shop can check these problems for reasonable cost. Make sure the basics are OK before adding a lot of gimicks to fix the problem.

Bill.

[Barney Eaton]

While I have yet to overheat (boil over) I am wondering about a few things.....

(1) do any of the anit-rust/water pump additives raise the boiling point?

(2) is there any advantage to adding a overflow tank?

I am considering adding an electric fan...... my thoughts are to find a common 12v fan and run it on 6V..... DC motors will run at half speed, and if their life is shortned by that, then they are readily available.

Second how about rigging one of thes patio misters to a garden sprayer. with a manual valve or even a solenoid valve, you could kick it in when in traffic. The mist should transfer heat but not be enough water to run all over the engine compartment. 1 or 2 mister heads on a 1 gallon garden sprayer should last quite a while in traffic.

Comments?

[egor]

Answer to question #1:

Evans Coolant has a boiling point of something like 375 degrees. It's pricey, but you never have to worry about boilover again, which may take care of question #2.