The Stovebolt Site Forums The Shop Area Engine Shop Thermostat

I think that the thermostat in my 216 isn't working, or is the wrong one. It got up to 180° F tonight, which, by my estimation, is twenty to forty degrees too hot.

So, I opened up my shop manual to see where the bloody thing is so that I can pull it, only to find that the author of the shop manual tells you how to remove and test it, but not where it is. I guess that he figures that it goes without saying.

So, anybody know where it is?

Should be in the housing where the upper radiator hose hooks up to the engine. Should be two bolts holding the housing in place. Will be round in shape.

180 is not too hot. A 160 is about the lowest generally available and with a good cooling system you will probably run between 180 and 190 on hot days regardless.

I know that 180 won't hurt anything, but she starts running really badly when she gets there. I've had her stall out on me before -- which isn't fun!

I was doing some tree pulling last night and checked the radiator temp with my handy dandy probe thermometer from he kitchen. It showed that the radiator temp was 183°, which suggests to me that the thermostat is working.

It seems to be better when I drive down the road, so maybe I just need to tear down my cooling system and have the components checked out.

The bad running may not be related to the coolant temperature, it could be the coil breaking down or the carb percolating due to underhood temperature. Also check the point gap and timing when engine is hot. Plugs could also be a problem.

Baldy is right. 180 is great, you probably have somthing else wrong for poor running after warm. UUUUH are you pushing the choke back in?

Yes. I'm not as dumb as I look.

Brendan,

I did a min-search on your engines operating temperature...the general consensus was 160F.

I am with you, I think 180 is too hot for this old stump puller. When you checked the radiator with your thermometer, where was the needle in the dash temp gauge. I'll bet if the gauge works, the needle was higher than mid scale, or normal.

If you can't control the engine temp with the "valve"...the thermostat, then the cooling system is plugged somewhere. Usually the tubes in the radiator!

If under hood temperatures are elevated to a state to cause other components to malfunction, I would definitely classify this as a coolant, or cooling system problem!


Stuart

I was sort of figuring that my running issue was a side effect of it being 180°, and not a direct effect. It runs fine -- beautifully, even -- at 160°.

The point gap is set to .18". I will check it when it's hot tonight.

The plugs were new and properly gapped as of last summer, but I replaced them with what had been in there, and those may have been incorrect.

The Coil, AFAIK, is original to the engine and may indeed be giving up the ghost. I will look into a replacement.

Carb Percolation... How do I stop it?

Hi Stuart!

My shop manual says that the stock thermostat in these old girls was a 140° model, but if you run coolant/antifreeze all of the time, then they suggested a 160° model. From what I can tell, dealers often did the swap before they were sold.

Obviously, I have no idea what is in there; my grandpa is infamous for having the 'fix it so that it works now' mindset, so it probably has the wrong one. But, seeing as I'm not quite done with my tree pulling project, I'm a bit reluctant to tear into it right now.

The gauge was pointing at 180(ish) when I tested the radiator, which is why I suspect that the thermostat is working. (I was also shocked as hell, but that's another story. )

The pump is definitely moving water/coolant: I can see it moving when I look into the radiator.

Another thing that might be an issue is that the radiator is mounted ahead of the support ring, with a pretty good gap between it and the fan. I'm not sure why this was, but I do know that the truck has had the engine out of it five times, and I assume that someone either had a longer engine in there (e.g. a GM) or they just moved it ahead to make it easier to pull the block out. Either way, they never put it back where it belonged.

I will check on the components that Baldy suggested and check my hoses in case there is a kink or something something somewhere.

If all else fails, I'll take it to the radiator shop.

Does the motor diesel at all? What kind of carburetor do you have? My junker Rochester B would ALWAYS percolate and the floats would stick... I've gotten use to carrying around a long screw driver so I can whack it a few times; should it decide to throw a fit. It seems to work, the floats unstick that way. If you have a Rochester B, consider getting a Monojet! Check timing, valves, blah blah blah.

They've got special chemicals (kind of like liquid Drain-o) that you can flush through your cooling system and then replace all of the water 2 or 3 times. I know a 250 isn't a 216, but I think that 180 deg is perfecly acceptable. My engine runs reall good up until 200deg and then begins to crap out on me. So I figure anything between 160 and 190 is acceptable, after that is when I get paranoid.

So, you should go to a 160 thermostat and just flush your cooling pipes.

I'm not sure what you mean by dieseling, but it does sound a little bit like a diesel when it's running badly.

I'm running the Venerable Carter W-1 on the old girl. I've nver had a problem with percolating, but I suppose it's possible. The float only got stuck that one time when some crap got into the needle valve. I rebuilt the carburetor and put in a filter (which I just changed the element on).

My 216 runs on the stock non-pressureized cooling system, which means that 212° is its "red line" -- at least, on the gauge. I agree that 180° won't physically hurt the block, but the temp gets a little too warm and stuff stops working right. :mad:

I'm sort of thinking about just pulling the thermostat out and eliminating that point of failure. I don't drive it in the winter, so that won't really be too much of an issue not having one. Besides, my panel of illustrious old fart mechanics (namely, my 80 year old uncle) tell me that I "don't need any !@#$%&! thermostat". He's an interesting man, my uncle.

I may have to give that radiator drano a shot.

They got you too, huh?

[snerk]

I think that Fumbin46 said it best when he said:

"My '46 two ton truck with a 235 has enough torque to change the rotation of the earth in 1st gear."

By "dieseling", he means does it run on when the ignition is turned off? Often engines that ping will also run on, but 216s are unlikely to ping because of their low compression. Your carb could be percolating if you don't have a phenolic spacer between it and the manifold. A heat riser sticking in the warm up position can also cause percolation. You might try advancing the timing a bit to see if that helps the cooling, as insufficient advance often causes overheating.

Brendan,

Just what the heck is a "theromstat" anyway? I thought you told us you weren't as dumb as you looked.


Stuart-Merriam-Webster

Ah. No. There's no run on. You turn the key, and she shuts right off.

The Carb is mounted right on the manifold, just as GM intended. I know where to get spacers, though.

Can a heat riser stick after the truck's been running for a while?

I can try playing with the advance a little.

I just have fat fingers!

You definetly need that spacer and it was normally there. Its actually a heat insulator intended to avoid heat related issues with the carby. Cheap and easy to install though I have found slow and careful is in order or you will crack it because its a tight fit. I do think you have other issues thogh. If you are serious about what is a thermostat its a bi-metallic device that fits between the upper hose "goose neck" and the block. It opens at a predetermined temperature and designed to allow the water temp to reach a given temp and maintains it by opening at that temp to allow water circulation to the radiator. Until it opens the water only circulates in the engine. The thermostats can be put in backwards so be careful when installing. I have been running a 180 degree thermostat in my '51 216 for years without any issues whatsoever.

I've ordered the spacer.

I'll report back as soon as I put it on.

180 is normal operating Temp for the 216 here in the DFW area on my truck, runs great with no problems.If you radiator boil's over you got different problems.I still use the 4lb.originional cap.Flush your radiadior.

Brendan

Don't be tempted to run without a thermostat - just replace it if you suspect it is faulty. If your engine's running too cold it will suffer more than running too warm (within reason). As long as the thermostat is working normally, & is correct for your engine, it won't be contributing to any overheating problems.

Beaver:

I haven't had it boil over yet. I think the main problem with the way it runs when it hits 180 is the lack of a spacer plate under the carb. Either that, or the coil is about to die.

A Radiator flush is on the list of things to do, but it is pretty far down the list.

Ken:

I haven't torn into the thermostat yet. Once I do, I'll check to see what it is, and get the right one if it's not.

Brendan M. I agree with you on both.