I would not be so fast to say that if you read some of the post.
It sounded like he changed the stat, 195* in also normal for my 300 six, but did not refill the radiator or let it run with the cap off to "burp" air out of the system.

When cold he should open the radiator and top off the coolant. leave cap off and get the motor up to temp.
It nay burp coolant out when the stat opens but should level off after the stat opens a few times.
Top it off cap it and make sure you have a hose to the over flow tank and it goes almost to the bottom.

Dose the factory temp gauge work?
Think you said you can measure temps?
If yes to both good. When out to temp the factory gauge should be in the middle.
Measure the temp at the stat housing, top of the radiator and if you can the bottom. Top should be hotter than the bottom.
Till we have numbers of the cooling system it is a guess if over heating.

That is my take on this
Dave ----

ps if the radiator level is low look inside at the tube ends do they have any crusty stuff around them?

 

Here's a search for PCV air filter, so he may have an idea what one is.

https://www.google.com/search?q=pcv+air+filter&sca_esv=a24d50f4328fb081&r lz=1C1OKWM_enUS906US906&sxsrf=ADLYWIKbSi77m6aZX6U1 pfK_-akLyFGhqA%3A1716988262295&ei=ZilXZoPaEeuuptQP4P6wk Aw&oq=pcv+air+filter&gs_lp=Egxnd3Mtd2l6LXNlcnAiDnB jdiBhaXIgZmlsdGVyKgIIADIKECMYgAQYJxiKBTIGEAAYBxgeM gYQABgHGB4yCBAAGAcYHhgPMgYQABgeGA8yBhAAGAUYHjIGEAA YCBgeMgYQABgIGB4yCxAAGIAEGIYDGIoFMgsQABiABBiGAxiKB Ui6KVD0CFjiC3ABeAGQAQCYAWugAcMBqgEDMS4xuAEByAEA-AEBmAIDoALeAcICChAAGLADGNYEGEfCAgsQABiABBiRAhiKBZg DAIgGAZAGCJIHAzIuMaAHqgw&sclient=gws-wiz-serp

 

Welcome to the forum. Now, where did I leave my 11-foot pole?

The following is meant in the kindest, most gentle manner possible. When troubleshooting, a good rule of thumb is to avoid running around in circles like a chicken with its head cut off. Three pages so far in less than 24 hours, all over the place! Just reading the story so far, I feel like I'm trapped inside a pinball machine. Overheating! Zing! New thermostat! Zing! Fumes from the valve cover! Zing! Puking coolant! Zing!

To get to the bottom of the issue, I've been authorized to break out the forum tranquilizer dart gun. This short educational video explains the process:


It's important to understand this is for your own good. Do NOT pull out the dart. When you regain consciousness, we can take our time and figure out exactly what is happening. My hunch is nothing serious is afoot. You've probably got a few minor issues that need some love. Once these items are corrected, you may have yourself a nice truck. Remember, there may be more than one fault, so don't expect a magic fix in one shot.

1) Who installed that metal line on the top of the passenger side valve cover? That is part of the Positive Crankcase Ventilation (PCV) system and is designed to clear harmful fumes from inside the crankcase. The metal line is designed to fit nicely inboard of the valve cover, on top of the engine. How in the world did Bubba cobble that together like he did? You will need to hide in the bushes at his house and wait for him. When he appears, jump out, take him by surprise, and beat the snot out of him. Brass knuckles are recommended. He'll know why you're there. You won't need to say a word. Workmanship like that has me shaking my head.

2) The PCV system long predates any emissions controls, and is VERY beneficial to the engine. Over on the driver's side valve cover, you need a filter on that open port where oily fumes are escaping. In the factory configuration, a hose connected to a separate filter inside the air cleaner housing. Because air is usually sucked into that open port, and the original filter arrangement is long gone, you will need to figure out something else. Some of the previous links showed some options.

3) Oily fumes escaping from that open port is NOT a major cause for concern. Normally the PCV system draws fresh air into that port. Under certain conditions, oily fumes can blow back out instead, especially at idle. This is more prevalent due to normal wear as an engine ages and is no need to panic. My 351W did that for years and I put many miles on it. You do need a filter on the open port, but don't worry about the presence of fumes.

Here's a good link explaining the operation of the PCV system:

https://www.aa1car.com/library/pcv.htm

4) The PCV valve itself plugs into the passenger side valve cover. It might be worth replacing it, as they are a normal wear and tear item.

5) Puking coolant from the small hose below the radiator cap? The cap is designed to vent if pressure gets too high, but a bad one could be venting early. Gamble $10 on a quality replacement cap and see what happens.

6) Self-induced fears about a blown head gasket? Beg, borrow, or steal a cooling system pressure tester. This looks like a bicycle tire pump with a gauge on it, and connects to the radiator neck in place of the cap. Pump up the system to the rated value on the cap. Watch the needle and wait 15 minutes. If the system is good, the gauge will not drop more than a needle's width. If the pressure does drop, we can walk you through further steps to isolate the leak. Don't automatically convince yourself a bad head gasket is the only possible source. Some auto parts stores have free loaner tools, so don't worry about the expense.

7) You mentioned having an infrared thermometer. With the engine warmed up, measure the temperature at the thermostat housing. Use this value to determine what's really going on with the temperature.

 

When he shut down the engine that's when the overflow bottle overflowed. When I shut down the radiator begins to take water back from the overflow bottle. He said coolant appeared to be boiling out. Makes me question the condition of the radiator. If the radiator is plugged up shutting down could heat coolant in the engine more causing the boil over. You do need a good radiator, good cap and clean coolant to expect your cooling system to work properly. Some people put tap water in their system and that will eventually kill your cooling system and soon after your engine.

 

UPDATE!!
I changed hoses on the pcv valve and sure enough no more white smoke. I also added a rag attached by a wire on the breather tube as suggested. Now i am running it with the radiator cap off and saw that the level dropped. So that means thermostat is working correct?

just shut it down and now i have to go buy more coolant lol. I will get temp readings tonight hopefully.

 

Yes, when the T stat opens it sucks, or water pump, pumps coolant into the engine.

What does the seal look like on the radiator cap ?
Here's what my 86 gets,

 

UPDATE #2

No more smoke from oil breather or cover gasket. It seems putting a better hose on the pcv valve worked for this issue. My guess is that it was clogged.

I drove for around 10 minutes and when I returned home, no more steam shooting out of the radiator overflow hose! I did however feel my upper radiator hose and it feels like it’s pressurized? That that normal?

also here’s a picture of the cap.

 

Cap looks shot to me. Replace it. Consider the lever release type. Also a new truck to you maybe flush your cooling system. Is that rust I see on the cap? Gasket is cracked up.

 

I will buy a new one soon. And no, not rust just orange fluid from radiator.

also, temps
thermostat housing 225 degrees
top of radiator 240 degrees
bottom of radiator 234 degrees

these temps fluctuated A LOT so it was hard ti get a soild reading. Do these seem accurate? Should i re-try it?

 

Orange coolant ???

It should be green. or is it, https://www.google.com/search?q=oran...client=gws-wiz

Along with a new cap, maybe pick up a coolant tester, they are a few bucks at Walmart. and check out how good the coolant is for low temp.

In the morning, check the coolant level, before you start it. Top off to the bottom of the neck, if needed.

 

Yeah it’s orange from inside the carburetor I mixed water in with the coolant just to test out things. Got new bottle of coolant sitting in the cab with a new radiator cap. Autozone says I can buy the tester kit and use it and then return it for my money back so I’m going to do that sometime this week.

I also wanted to take the opportunity to thank everyone who has added input to this thread. I can be a little squirrelly at times but I think we’re doing a lot better since I replaced the pcv valve hose. If the issue of overheating is still present tomorrow I plan to create a new thread to clean up from the pcv valve discussions.

Before I close this out can anyone tell me what temp ranges are normal for my thermostat housing, upper radiator, and lower radiator? Any comments on where to measure and what temps they should be would be helpful.

Thank you all again. God bless.

 

I am pretty sure when he changed the stat he did not purge the air out of the system so when he shut it down it burped the air out.
The rest you are right on but I think he needs to get the system from burping and that sounds like he is good now.

Way to go with the PCV

If there was air in the cooling system then yes when the stat open it would drop.

Yes the cooling system will build pressure as it heats up this innormal.
If you look on the cap it will show something like 13 psi again normal.
For every 1 PSI the boiling point goes up 2* So if water boils at 212*f put a 1 psi cap on and it will now boil at 214*f
I will let you do the math for a 13 psi cap and when the water will boil. Add coolant mix and that will raise it some also.

I dont think the cap looks bad but will not hurt if you got anew one.

I think you meant radiator not the carb
Yes some coolant is orange and I thing AZ is that way for "all makes cooling systems".

BTW the tenps you got with the gun seam high but if they are all close I would not worry too much at this time.
The reading will be higher at the stat * top of the radiator as hot coolant from the motor come out there.
As it goes thru the radiator and cools down temps at the bottom will be cooler.
If you can get to the front of the radiator, no AC, motor cold cap off watch for when the water moves / stat opens.
You can also feel the upper radiator hose for when it gets hot.
Then feel the front of the radiator core in different areas. If the tubes are not plugged you should feel the same temp every where on the core.
Do the same after the stat opens a few times, be careful as it can now be pretty hot. Any cold spots means clogged tubes and they are not cooling the coolant.
I dont know if a temp gun will show this or not?
Dave ----

 

IF (big if) the cooling system is working properly, those numbers are a bit high. Normally you'll see within about 10 degrees of the thermostat rating. Please note I did not say to rush out and buy another thermostat, at least not yet.

When test results don't seem to make any sense, I like to revisit the whole process. For example, it's possible your thermometer is inaccurate. I'd check that first. To test, boil a pot of water on the kitchen stove. With the water boiling, measure the outside of the pot. The water and pot should be right around 212F. (Measuring the water itself with an infrared gun may give inaccurate results.) So if your gun shows the pot close to 212F, we know it's accurate. If not, we'll have to adjust the readings.

Different materials measure differently with an infrared gun. It's best to take readings on metal, not rubber hoses.

The readings on the radiator? You have a crossflow radiator, where hot coolant leaves the engine via the upper hose and enters the passenger side of the radiator. Coolant then flows sideways to the driver's side of the radiator, for return to the engine. Airflow through the radiator core should drop the temperature at least 30F from inlet to outlet. So regardless whether your thermometer gun is accurate, look for a drop of at least 30F across the radiator.

If you see less than this, there are two main possibilities.

1) Inadequate airflow through the radiator core will reduce heat transfer. This could be bugs and debris blocking the airflow passages. A missing radiator shroud will reduce the airflow, but I see one in your pictures.

2) Scale can build up inside the radiator and act like an insulator. This reduces heat transfer, too. Coolant is still flowing, but heat is not being transferred to the air like it should.


Check the temp drop from radiator inlet to outlet and let us know what you have. This will help determine the next steps to take.

 

I like the idea of checking engine, cooling system, with the infrared thermometer. I checked my IT with a pot of boiling water. Perfect. Then went to my truck to check temps there. I have the 6.9l diesel the thermostat is 190 and was checked before installation. Shooting the thermostat cap on the 6.9 was way below 190. The cap on the diesel is very thick. The engine block is also very heavy. Even when fully warmed up the highest temp I could find was right on the temperature sender and that was 185 max. I know the coolant flowing past the thermostat has to be 190 but with the heavy duty diesel engine I got around 170 on the cap. Diesels dissapate heat well. So you will read lower temps on the exterior. With gas engines you probably will measure temps closer to your thermostat rating.

 

Just finished playing in the kitchen with my infrared thermometer. I wanted to verify my theory about checking the accuracy with a pot of boiling water. I figured boiling water would be an easily duplicated reference and is right in the range we'd expect to see for a cooling system.

I had been thinking the infrared action has trouble measuring liquid temperatures, but it seemed fine. With the water boiling, I recorded 206F. My home is about 1000' elevation. That drops the boiling point to 210F (didn't factor baro pressure), so I'd say a difference of only 4F is pretty much right on the money.

However, I was surprised when I tried measuring the outside of the pot. It's stainless steel, maybe .050" thick. I would have expected it to be very close to the 206F for the water inside. Instead, I'd see about 100F, a SUBSTANTIAL difference. I know different materials affect the accuracy of an infrared reading, but I wasn't expecting such a major variance.

In the past, I've measured radiator inlet temperatures and they were close to the thermostat rating, which seemed reasonably accurate. Maybe there's something about the reflectivity of stainless, I don't know.

Edit: Tried again with a different pot. Got about 220F for the outside of the pot, which seemed more reasonable. Moral of the story? Don’t use stainless.

Back to those circa 230F readings you got. Was this after a test drive, with lots of radiant heat under the hood? That could be skewing your results. I'm still curious what you record with boiling water. Just want to be sure your infrared gun is reasonably accurate.