The Stovebolt Site Forums The Shop Area Engine Shop My 235 is getting warm

I have been driving My 59 for about two summers with my new A/C unit installed. It has been doing great however, this past Sunday I drove her about 2 miles to the Wall-Mart and she started spilling the coolant, when I turned off the motor. I didn't realize the guage was hot.
.. I went ahead and bought some more coolant there at the store, drove her home and checked the oil, belts and radiator... everything was good.

Tonight I drove the bolt to work with the A/C on, and again she got hot. I turned off the A/C, and drove for several more miles. Even at a stop light she was ok, no overheating. As long as the A/C unit was off she ran cool. It is still 90+ degrees here in Texas, nothing has changed from this summer...

Is there any thing else I should look for?

What am I forgetting?


Cliff59

Check and make sure your thermostat is opening. You shouldn't run a high % of coolant (antifreeze) in that hot weather...you might want to consider an 80%water /20% coolant mix...more water..better cooling.

I think the thermostat is ok... but I will check it out (or change it out) this week.

I have been running 50/50 but I will go ahead and make it an 80/20 mix.

Thanks

CLIFF59,

My thought would be to take a peek into the radiator...it is the variable in this situation.

Is it possible that it is becoming plugged and is just over the threshold of being able to cool your truck with the added load of the AC compressor on the engine.

Stuart

Huuuummmmmmm...... ???????

I have checked the Radiator before but not in about 6 months... I have never noticed plaque
or anything out of the ordinary.

I will take a closer look this week.

Thanks Stuart


Cliff59

I was having some of the same problems with my ride. Running a 50/50 mix with new alum. radiator with A/C on. Pull off the interstate into heavy traffic in August and the heat would build. The people who built my radiator said the thing is good for a lot more ponies than my L6 is making. I noticed my aftermarket radiator cap was getting corrosion on it. Got a "water-wetter" as it has anti-corrosive stuff in it. The antifreeze mix is 25/75 with a quart of this "water-wetter" in it. The heating problem has gone away. No more than a 5 deg. swing in any traffic condition. Don't know what fixed it...the ratio mix or the "water-wetter".

I go about 70/30 alla time here, it just don't get that cold to need 50/50.

Ethylene Glycol is denser than water and will therefore carry more heat away from the engine. The boiling point of Ethylene Glycol is up around 275°F vs 212°F for water. The reason that 50/50 mixture is commonly recommended is because it is a good all round mix that gives better heat conduction than plain water and covers most of the low temperature conditions that we run into in the States. Most Ethylene Glycol manufactures call out a maximum 70% mixture should you be exposed to extreme cold which will give you protection down to –75°F or –80° F. Of course these numbers will vary depending on the pressure the system is under.

If you didn’t have cooling problems in the past then it is only logical to assume that you are having a problem with the stat, the cap or with a blockage somewhere in the cooling system.
Denny Graham
Sandwich, IL

This may sound like a silly question, but have you cleaned all of the bugs out of your A/C condensor and/or your radiator. I had the same symptoms you are describing with my 1991 Chevy truck when I lived in Stephenville, TX. It seems like the spring and early fall are bad times for bugs building up and blocking the airflow through your radiator. Since this has been a wet year, the bugs are probably worse.

Denny,plain water is a better coolant than Glycol,but water obiviously doesn't have frreze or corrosion protection.

I been all through this , Fast truck has it right . Water is best at transfeering heat . The water wetter is supposed to help but have heard it were it did nothng , yea I poured a bottle in my drag car .Anti freeze is just that and a anti corrosion agent .
On my nova i have gone to a electric fan, A few extra HP from not having that fan to spin and better cooling . I use a 2 spd fan from a ford Taurus , pulls a suprising 3200cfm

As a point of fact, pure water transfers heat about 50% better than anti-freeze or a substantial anti-freeze mix. However, as previously noted anti-freeze does raise the boiling point and is a corrosion inhibitor. So a mix based on your temperature situation is indicated.

Also, make sure timing is up to specks, and the vacuum advance is working properly. If it still has points, double check the dwell.

If the timing gets a little slow, it will cause heating problems.

Just read this paper and I stand corrected. http://crownsolutions.com/pdfs/Glycol.pdf I have been operating for more years than I care to admit under the false assumption that the denser fluids would transfer the heat best. Learning something new every day is what keeps life interesting.
Denny Graham
Sandwich, IL

changed the thermostat and the oil.
had the radiator checked and..............

the Radiator is A-OK
the oil was getting thick and bad.
the thermostat looked ok but (what the hay)?

now the bolt is running cool! and happy,
even with the A/C running and at a stop light!


thanks guys

Cliff59

good to know info!


cliff59