The Stovebolt Site Forums The Shop Area Engine Shop Overheating ?

My 235 seems to be overheating all of a sudden. My temp gauge is new but seems to be broken...maybe by being over heated ? So I just ran my truck for about 15 min and left it at idle when I got home for a few minutes to check the block in various places with a laser pyrometer. Is that a reliable way to check for overheating ? Sure seems logical. Yep, it's reading 205 + on each side and top of radiator is 212.

The elec fan is set to come on at about 180 but it's not on. Also I guess could be bad water pump or thermostat...or ? The whole motor was rebuilt from the ground up last Spring

Mark, sounds like it might be the sending unit for the electric fan. Try jumping the terminals to turn the fan on. If that works, and the fan is not coming on at temperature as you describe, it is probably a bad sending unit.

Matt

Electric fan not working and you wonder why it is over heating? Do you have a mechanical fan in addition to the electric one? What year is your 235?
Carl

No Carl... I don't wonder. That's only one possibility. Sometimes it comes on and other times it does not.

Yes reliable way, but not on radiator. Check block. Check inlet hose vs outlet hose on Rad. Many engines are at operating temp at 195-215 deg. Isn't electric fan supposed cycle on and off depending on it's own thermostat switch? (you say it works sometimes)
What is answer as to if you have a mechanical fan?
First thing to do it check "new" temp gauge and sender in a pan of water with a kitchen thermometer. You have to be sure if it's working or not. Use the laser also, so as to calibrate it at the same time.
What exactly makes you think it is overheating?

What made me think it's over heating is that the new temp gauge went max hot and now has stayed there....must be defective. So then I got out the pyrometer and checked all over.... Block after a 20 drive is 210 or so...different places show different temps but all high. Yes, I think the fan is in play here and no I don't have a mech fan. Does not seem to be room for it. My motor is 235 from 57 car... There is a fan shroud which seemed to help. It's been holding temp fine until this new gauge went south. I think ? that over heating can destroy these gauges. ???

If it's an electric gauge, can't be hurt by heat. Mis-wire, yes. Mechanical gauge: don't think so either. Why are you blaming the gauge? May be the sender. Aye? At any rate, check them on the stove!
My guess is that it is not over heating and I think that is what you are thinking also. Make sure timing is correct while you are at it. That can cause a little heat. If you have the correct radiator cap and thermostat and it is not boiling over like crazy, it's not hot.

These are all mechanical and the sending unit, tubing, and gauge are all part of the same unit...no parts can be replaced. No not boiling over. Water pump and thermostat work OK... Fan may be the problem

Probably. Sounds like you have a handle on it.

If you want to go with a mechanical fan, you can make room for it and place it in the center of the radiator with an early style water pump relocation/adapter plate (search pre-'68 Dave water pump adapter plate), and a pre-'55.1 water pump (it sits higher than the '57)
I have never been a big fan of electric-only cooling fan setups. I can tell when my fan belt flies off, but I can't tell the difference between if the electric fan shuts off because it isn't hot enough, or if it shut off because of a defective sensor/fan motor, and meanwhile the engine is overheating.
Carl

I would not want just an electric fan either and you have now seen why.

I wasn't happy with the system either. We looked at that re-location plate and it just didn't look good with so few attachments. We opted for elec only. Just had it fixed. It was the fan controller. I'll talk to my guy again and see what he thinks about putting in a mech fan and using the re-location plate...Big job but likely worth it. This controller lasted only a few years...not good.

Glad you got it working. That plate system Carl is talking about from Dave: lot's have used it, lot's have loved it. They say it's not hard to do if you have some mechanical skills.
http://www.fiftee6.com/Water%20pump%20adapter%20plate%20install/

I am familiar with the plate and it's popularity. My mechanic was not and was not sure it would hold up with limited mounting bolts. He talked me into the elec fan. Next time I need to tear down a bit I'll likel go with it and the mech fan.

Roger.

You need to change your bumper sticker unless you REEEEALLY want her !!!... LOL

I talked to my mechanic yesterday about this plate and he told me that it won't work on my motor because it's a car motor. I had bought one but he couldn't see where it went and how it mounted so he called around and that's what he found out. He never mentioned that to me before....or I just plain forgot which is likely the case

Your mechanic should join this site

You should find a different "mechanic"- - - -he gives real mechanics a bad name! There's no difference in "truck" and "car" 235 engines where the water pump mounting is concerned.
Jerry

That is just what he was told when he tried to research installation info. He doesn't specialize in this era of cars and trucks. Having said that, he has done excellent work for me for the past two plus years and taught motor shop at the local HS for several years before opening his own shop.

It just sounds like he doesn't want to work on an old vehicle and he's making up excuses not to. There's nothing difficult about the relocation plate- - - -it replaces the rear plate on a 216/early 235 water pump and requires drilling/tapping two holes in the front of the block. I taught high school auto mechanics for over 30 years, and just about any of my first-year rookies could have accomplished that job in a couple of hours.
Jerry

There's no need to start trashing people you don't know a thing about... He does a darn good job but may have gotten bad info from somewhere. No one knows everything...not even you.

In my opinion, your darn good mechanic (and I'm sure he is) needs to learn how to say, "I don't know" after someone introduces him to another way to solve a problem, especially one with the successful track record which this adapter plate has. Once he learns that skill, he will become an excellent mechanic.
Carl

Uhhhh, Carl. He did say I dunno and asked someone. Turns out that someone, whom he trusted at the time, maybe gave him bad info. How many times do I have to say this ??? Geeeze..

Drop this already... Da** this is a tough crowd...

Well I don't know how tough this crowd is, and I will certainly drop it after this post, but you inquired about what you should do, implied that your mechanic gave you incomplete information on how to remedy the situation, and I tried to lead you in the right direction. It is entirely up to you what to do now.
I meant no disrespect to you or anyone else. I'm just trying to help.
Carl

OK...fine