[AT] [Farmall] Engine Overheating

[Mike Sloane]

There are a LOT of reasons for a thermosyphon equipped engine to run 
hot, not just crud in the block:

  - Timing too far advanced
  - Cracked/warped head
  - Blown head gasket
  - Loose fan belt
  - Clogged radiator tubes
  - Clogged radiator fins
  - Collapsed lower hose
  - etc.

Take a look at the spark plugs - on an inline 4 cylinder engine, No. 4 
is usually the one that gets the hottest, especially when there is crud 
in the cooling system. If all the plugs look about the same, your 
problem may not be with crud. If you can borrow or find an infrared 
thermometer, that is something that is very handy for checking block 
temperatures. They used to be expensive, but I was able to pick one up 
for about $25 recently. They are also handy for checking the temperature 
of ignition coils, radiators, coolant temperature, hydraulic reservoirs, 
etc.
<http://www.harborfreight.com/infrared-thermometer-93984.html> and 
<http://www.harborfreight.com/non-contact-laser-thermometer-96451.html> 
are two examples, but I am sure you can find others.

Once you have eliminated all of the above, you can try various cooling 
system cleaner/flush products, although I am told that the current 
formulations are all but useless due to concerns about "product safety". 
The old stuff was mostly lye (I believe). There may be better compounds 
that only radiator, coil cleaning, engine rebuilders, and similar shops 
can buy.

There is one thing you can do before hauling the block down to the shop 
for "boiling out": you can remove all of the expansion plugs (also 
called "core" plugs), dig as much crud out as possible with whatever 
tools will fit, and then force air and/or water through those holes. The 
plugs are easy enough to remove with an awl or ice pick, and getting new 
ones back in isn't difficult (I use a socket turned backwards with a 6" 
extension, and tap them with a hammer, but I have seen some mechanics 
just set them with a ball peen hammer). Core plugs are cheap and come in 
standard sizes, so replacing them is not only inexpensive but a good 
idea on any old engine.

Here is an image of my Ford block with the plugs removed. I was taking 
the engine out anyway to have it worked on. 
<http://public.fotki.com/mikesloane/1946_ford_2n/2n_overhaul_4_4_05_08.html>

Mike

On 7/26/2011 3:58 PM, Ben Wagner wrote:
> Hi,
>
> I'm suspecting that my Farmall A is running very hot.  The coolant boils
> even after running the engine for 10 minutes, and the block can burn an
> unsuspecting hand.  I can run my Super A for the same amount of time, but
> the A is much hotter afterwards.  Part could be the engine, I know, but I'm
> also wondering if there isn't built-up deposits inside the engine that
> blocks the coolant flow.  This is a thermosyphon system.
>
> Is there any way to clean the cooling system in the block without taking the
> engine apart?
>
> Thanks!
>
> Ben Wagner
> _______________________________________________
> Farmall mailing list
> http://www.antique-tractor.com/mailman/listinfo/farmall
>